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39 hoursMerge tag 'net-next-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core & protocols: - Wrap datapath globals into net_aligned_data, to avoid false sharing - Preserve MSG_ZEROCOPY in forwarding (e.g. out of a container) - Add SO_INQ and SCM_INQ support to AF_UNIX - Add SIOCINQ support to AF_VSOCK - Add TCP_MAXSEG sockopt to MPTCP - Add IPv6 force_forwarding sysctl to enable forwarding per interface - Make TCP validation of whether packet fully fits in the receive window and the rcv_buf more strict. With increased use of HW aggregation a single "packet" can be multiple 100s of kB - Add MSG_MORE flag to optimize large TCP transmissions via sockmap, improves latency up to 33% for sockmap users - Convert TCP send queue handling from tasklet to BH workque - Improve BPF iteration over TCP sockets to see each socket exactly once - Remove obsolete and unused TCP RFC3517/RFC6675 loss recovery code - Support enabling kernel threads for NAPI processing on per-NAPI instance basis rather than a whole device. Fully stop the kernel NAPI thread when threaded NAPI gets disabled. Previously thread would stick around until ifdown due to tricky synchronization - Allow multicast routing to take effect on locally-generated packets - Add output interface argument for End.X in segment routing - MCTP: add support for gateway routing, improve bind() handling - Don't require rtnl_lock when fetching an IPv6 neighbor over Netlink - Add a new neighbor flag ("extern_valid"), which cedes refresh responsibilities to userspace. This is needed for EVPN multi-homing where a neighbor entry for a multi-homed host needs to be synced across all the VTEPs among which the host is multi-homed - Support NUD_PERMANENT for proxy neighbor entries - Add a new queuing discipline for IETF RFC9332 DualQ Coupled AQM - Add sequence numbers to netconsole messages. Unregister netconsole's console when all net targets are removed. Code refactoring. Add a number of selftests - Align IPSec inbound SA lookup to RFC 4301. Only SPI and protocol should be used for an inbound SA lookup - Support inspecting ref_tracker state via DebugFS - Don't force bonding advertisement frames tx to ~333 ms boundaries. Add broadcast_neighbor option to send ARP/ND on all bonded links - Allow providing upcall pid for the 'execute' command in openvswitch - Remove DCCP support from Netfilter's conntrack - Disallow multiple packet duplications in the queuing layer - Prevent use of deprecated iptables code on PREEMPT_RT Driver API: - Support RSS and hashing configuration over ethtool Netlink - Add dedicated ethtool callbacks for getting and setting hashing fields - Add support for power budget evaluation strategy in PSE / Power-over-Ethernet. Generate Netlink events for overcurrent etc - Support DPLL phase offset monitoring across all device inputs. Support providing clock reference and SYNC over separate DPLL inputs - Support traffic classes in devlink rate API for bandwidth management - Remove rtnl_lock dependency from UDP tunnel port configuration Device drivers: - Add a new Broadcom driver for 800G Ethernet (bnge) - Add a standalone driver for Microchip ZL3073x DPLL - Remove IBM's NETIUCV device driver - Ethernet high-speed NICs: - Broadcom (bnxt): - support zero-copy Tx of DMABUF memory - take page size into account for page pool recycling rings - Intel (100G, ice, idpf): - idpf: XDP and AF_XDP support preparations - idpf: add flow steering - add link_down_events statistic - clean up the TSPLL code - preparations for live VM migration - nVidia/Mellanox: - support zero-copy Rx/Tx interfaces (DMABUF and io_uring) - optimize context memory usage for matchers - expose serial numbers in devlink info - support PCIe congestion metrics - Meta (fbnic): - add 25G, 50G, and 100G link modes to phylink - support dumping FW logs - Marvell/Cavium: - support for CN20K generation of the Octeon chips - Amazon: - add HW clock (without timestamping, just hypervisor time access) - Ethernet virtual: - VirtIO net: - support segmentation of UDP-tunnel-encapsulated packets - Google (gve): - support packet timestamping and clock synchronization - Microsoft vNIC: - add handler for device-originated servicing events - allow dynamic MSI-X vector allocation - support Tx bandwidth clamping - Ethernet NICs consumer, and embedded: - AMD: - amd-xgbe: hardware timestamping and PTP clock support - Broadcom integrated MACs (bcmgenet, bcmasp): - use napi_complete_done() return value to support NAPI polling - add support for re-starting auto-negotiation - Broadcom switches (b53): - support BCM5325 switches - add bcm63xx EPHY power control - Synopsys (stmmac): - lots of code refactoring and cleanups - TI: - icssg-prueth: read firmware-names from device tree - icssg: PRP offload support - Microchip: - lan78xx: convert to PHYLINK for improved PHY and MAC management - ksz: add KSZ8463 switch support - Intel: - support similar queue priority scheme in multi-queue and time-sensitive networking (taprio) - support packet pre-emption in both - RealTek (r8169): - enable EEE at 5Gbps on RTL8126 - Airoha: - add PPPoE offload support - MDIO bus controller for Airoha AN7583 - Ethernet PHYs: - support for the IPQ5018 internal GE PHY - micrel KSZ9477 switch-integrated PHYs: - add MDI/MDI-X control support - add RX error counters - add cable test support - add Signal Quality Indicator (SQI) reporting - dp83tg720: improve reset handling and reduce link recovery time - support bcm54811 (and its MII-Lite interface type) - air_en8811h: support resume/suspend - support PHY counters for QCA807x and QCA808x - support WoL for QCA807x - CAN drivers: - rcar_canfd: support for Transceiver Delay Compensation - kvaser: report FW versions via devlink dev info - WiFi: - extended regulatory info support (6 GHz) - add statistics and beacon monitor for Multi-Link Operation (MLO) - support S1G aggregation, improve S1G support - add Radio Measurement action fields - support per-radio RTS threshold - some work around how FIPS affects wifi, which was wrong (RC4 is used by TKIP, not only WEP) - improvements for unsolicited probe response handling - WiFi drivers: - RealTek (rtw88): - IBSS mode for SDIO devices - RealTek (rtw89): - BT coexistence for MLO/WiFi7 - concurrent station + P2P support - support for USB devices RTL8851BU/RTL8852BU - Intel (iwlwifi): - use embedded PNVM in (to be released) FW images to fix compatibility issues - many cleanups (unused FW APIs, PCIe code, WoWLAN) - some FIPS interoperability - MediaTek (mt76): - firmware recovery improvements - more MLO work - Qualcomm/Atheros (ath12k): - fix scan on multi-radio devices - more EHT/Wi-Fi 7 features - encapsulation/decapsulation offload - Broadcom (brcm80211): - support SDIO 43751 device - Bluetooth: - hci_event: add support for handling LE BIG Sync Lost event - ISO: add socket option to report packet seqnum via CMSG - ISO: support SCM_TIMESTAMPING for ISO TS - Bluetooth drivers: - intel_pcie: support Function Level Reset - nxpuart: add support for 4M baudrate - nxpuart: implement powerup sequence, reset, FW dump, and FW loading" * tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1742 commits) dpll: zl3073x: Fix build failure selftests: bpf: fix legacy netfilter options ipv6: annotate data-races around rt->fib6_nsiblings ipv6: fix possible infinite loop in fib6_info_uses_dev() ipv6: prevent infinite loop in rt6_nlmsg_size() ipv6: add a retry logic in net6_rt_notify() vrf: Drop existing dst reference in vrf_ip6_input_dst net/sched: taprio: align entry index attr validation with mqprio net: fsl_pq_mdio: use dev_err_probe selftests: rtnetlink.sh: remove esp4_offload after test vsock: remove unnecessary null check in vsock_getname() igb: xsk: solve negative overflow of nb_pkts in zerocopy mode stmmac: xsk: fix negative overflow of budget in zerocopy mode dt-bindings: ieee802154: Convert at86rf230.txt yaml format net: dsa: microchip: Disable PTP function of KSZ8463 net: dsa: microchip: Setup fiber ports for KSZ8463 net: dsa: microchip: Write switch MAC address differently for KSZ8463 net: dsa: microchip: Use different registers for KSZ8463 net: dsa: microchip: Add KSZ8463 switch support to KSZ DSA driver dt-bindings: net: dsa: microchip: Add KSZ8463 switch support ...
3 daysMerge tag 'vfs-6.17-rc1.pidfs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull pidfs updates from Christian Brauner: - persistent info Persist exit and coredump information independent of whether anyone currently holds a pidfd for the struct pid. The current scheme allocated pidfs dentries on-demand repeatedly. This scheme is reaching it's limits as it makes it impossible to pin information that needs to be available after the task has exited or coredumped and that should not be lost simply because the pidfd got closed temporarily. The next opener should still see the stashed information. This is also a prerequisite for supporting extended attributes on pidfds to allow attaching meta information to them. If someone opens a pidfd for a struct pid a pidfs dentry is allocated and stashed in pid->stashed. Once the last pidfd for the struct pid is closed the pidfs dentry is released and removed from pid->stashed. So if 10 callers create a pidfs dentry for the same struct pid sequentially, i.e., each closing the pidfd before the other creates a new one then a new pidfs dentry is allocated every time. Because multiple tasks acquiring and releasing a pidfd for the same struct pid can race with each another a task may still find a valid pidfs entry from the previous task in pid->stashed and reuse it. Or it might find a dead dentry in there and fail to reuse it and so stashes a new pidfs dentry. Multiple tasks may race to stash a new pidfs dentry but only one will succeed, the other ones will put their dentry. The current scheme aims to ensure that a pidfs dentry for a struct pid can only be created if the task is still alive or if a pidfs dentry already existed before the task was reaped and so exit information has been was stashed in the pidfs inode. That's great except that it's buggy. If a pidfs dentry is stashed in pid->stashed after pidfs_exit() but before __unhash_process() is called we will return a pidfd for a reaped task without exit information being available. The pidfds_pid_valid() check does not guard against this race as it doens't sync at all with pidfs_exit(). The pid_has_task() check might be successful simply because we're before __unhash_process() but after pidfs_exit(). Introduce a new scheme where the lifetime of information associated with a pidfs entry (coredump and exit information) isn't bound to the lifetime of the pidfs inode but the struct pid itself. The first time a pidfs dentry is allocated for a struct pid a struct pidfs_attr will be allocated which will be used to store exit and coredump information. If all pidfs for the pidfs dentry are closed the dentry and inode can be cleaned up but the struct pidfs_attr will stick until the struct pid itself is freed. This will ensure minimal memory usage while persisting relevant information. The new scheme has various advantages. First, it allows to close the race where we end up handing out a pidfd for a reaped task for which no exit information is available. Second, it minimizes memory usage. Third, it allows to remove complex lifetime tracking via dentries when registering a struct pid with pidfs. There's no need to get or put a reference. Instead, the lifetime of exit and coredump information associated with a struct pid is bound to the lifetime of struct pid itself. - extended attributes Now that we have a way to persist information for pidfs dentries we can start supporting extended attributes on pidfds. This will allow userspace to attach meta information to tasks. One natural extension would be to introduce a custom pidfs.* extended attribute space and allow for the inheritance of extended attributes across fork() and exec(). The first simple scheme will allow privileged userspace to set trusted extended attributes on pidfs inodes. - Allow autonomous pidfs file handles Various filesystems such as pidfs and drm support opening file handles without having to require a file descriptor to identify the filesystem. The filesystem are global single instances and can be trivially identified solely on the information encoded in the file handle. This makes it possible to not have to keep or acquire a sentinal file descriptor just to pass it to open_by_handle_at() to identify the filesystem. That's especially useful when such sentinel file descriptor cannot or should not be acquired. For pidfs this means a file handle can function as full replacement for storing a pid in a file. Instead a file handle can be stored and reopened purely based on the file handle. Such autonomous file handles can be opened with or without specifying a a file descriptor. If no proper file descriptor is used the FD_PIDFS_ROOT sentinel must be passed. This allows us to define further special negative fd sentinels in the future. Userspace can trivially test for support by trying to open the file handle with an invalid file descriptor. - Allow pidfds for reaped tasks with SCM_PIDFD messages This is a logical continuation of the earlier work to create pidfds for reaped tasks through the SO_PEERPIDFD socket option merged in 923ea4d4482b ("Merge patch series "net, pidfs: enable handing out pidfds for reaped sk->sk_peer_pid""). - Two minor fixes: * Fold fs_struct->{lock,seq} into a seqlock * Don't bother with path_{get,put}() in unix_open_file() * tag 'vfs-6.17-rc1.pidfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (37 commits) don't bother with path_get()/path_put() in unix_open_file() fold fs_struct->{lock,seq} into a seqlock selftests: net: extend SCM_PIDFD test to cover stale pidfds af_unix: enable handing out pidfds for reaped tasks in SCM_PIDFD af_unix: stash pidfs dentry when needed af_unix/scm: fix whitespace errors af_unix: introduce and use scm_replace_pid() helper af_unix: introduce unix_skb_to_scm helper af_unix: rework unix_maybe_add_creds() to allow sleep selftests/pidfd: decode pidfd file handles withou having to specify an fd fhandle, pidfs: support open_by_handle_at() purely based on file handle uapi/fcntl: add FD_PIDFS_ROOT uapi/fcntl: add FD_INVALID fcntl/pidfd: redefine PIDFD_SELF_THREAD_GROUP uapi/fcntl: mark range as reserved fhandle: reflow get_path_anchor() pidfs: add pidfs_root_path() helper fhandle: rename to get_path_anchor() fhandle: hoist copy_from_user() above get_path_from_fd() fhandle: raise FILEID_IS_DIR in handle_type ...
2025-07-14don't bother with path_get()/path_put() in unix_open_file()Al Viro
Once unix_sock ->path is set, we are guaranteed that its ->path will remain unchanged (and pinned) until the socket is closed. OTOH, dentry_open() does not modify the path passed to it. IOW, there's no need to copy unix_sk(sk)->path in unix_open_file() - we can just pass it to dentry_open() and be done with that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/20250712054157.GZ1880847@ZenIV Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-07-08af_unix: Introduce SO_INQ.Kuniyuki Iwashima
We have an application that uses almost the same code for TCP and AF_UNIX (SOCK_STREAM). TCP can use TCP_INQ, but AF_UNIX doesn't have it and requires an extra syscall, ioctl(SIOCINQ) or getsockopt(SO_MEMINFO) as an alternative. Let's introduce the generic version of TCP_INQ. If SO_INQ is enabled, recvmsg() will put a cmsg of SCM_INQ that contains the exact value of ioctl(SIOCINQ). The cmsg is also included when msg->msg_get_inq is non-zero to make sockets io_uring-friendly. Note that SOCK_CUSTOM_SOCKOPT is flagged only for SOCK_STREAM to override setsockopt() for SOL_SOCKET. By having the flag in struct unix_sock, instead of struct sock, we can later add SO_INQ support for TCP and reuse tcp_sk(sk)->recvmsg_inq. Note also that supporting custom getsockopt() for SOL_SOCKET will need preparation for other SOCK_CUSTOM_SOCKOPT users (UDP, vsock, MPTCP). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250702223606.1054680-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08af_unix: Cache state->msg in unix_stream_read_generic().Kuniyuki Iwashima
In unix_stream_read_generic(), state->msg is fetched multiple times. Let's cache it in a local variable. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250702223606.1054680-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08af_unix: Use cached value for SOCK_STREAM in unix_inq_len().Kuniyuki Iwashima
Compared to TCP, ioctl(SIOCINQ) for AF_UNIX SOCK_STREAM socket is more expensive, as unix_inq_len() requires iterating through the receive queue and accumulating skb->len. Let's cache the value for SOCK_STREAM to a new field during sendmsg() and recvmsg(). The field is protected by the receive queue lock. Note that ioctl(SIOCINQ) for SOCK_DGRAM returns the length of the first skb in the queue. SOCK_SEQPACKET still requires iterating through the queue because we do not touch functions shared with unix_dgram_ops. But, if really needed, we can support it by switching __skb_try_recv_datagram() to a custom version. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250702223606.1054680-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08af_unix: Don't use skb_recv_datagram() in unix_stream_read_skb().Kuniyuki Iwashima
unix_stream_read_skb() calls skb_recv_datagram() with MSG_DONTWAIT, which is mostly equivalent to sock_error(sk) + skb_dequeue(). In the following patch, we will add a new field to cache the number of bytes in the receive queue. Then, we want to avoid introducing atomic ops in the fast path, so we will reuse the receive queue lock. As a preparation for the change, let's not use skb_recv_datagram() in unix_stream_read_skb(). Note that sock_error() is now moved out of the u->iolock mutex as the mutex does not synchronise the peer's close() at all. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250702223606.1054680-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08af_unix: Don't check SOCK_DEAD in unix_stream_read_skb().Kuniyuki Iwashima
unix_stream_read_skb() checks SOCK_DEAD only when the dequeued skb is OOB skb. unix_stream_read_skb() is called for a SOCK_STREAM socket in SOCKMAP when data is sent to it. The function is invoked via sk_psock_verdict_data_ready(), which is set to sk->sk_data_ready(). During sendmsg(), we check if the receiver has SOCK_DEAD, so there is no point in checking it again later in ->read_skb(). Also, unix_read_skb() for SOCK_DGRAM does not have the test either. Let's remove the SOCK_DEAD test in unix_stream_read_skb(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250702223606.1054680-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08af_unix: Don't hold unix_state_lock() in __unix_dgram_recvmsg().Kuniyuki Iwashima
When __skb_try_recv_datagram() returns NULL in __unix_dgram_recvmsg(), we hold unix_state_lock() unconditionally. This is because SOCK_SEQPACKET sk needs to return EOF in case its peer has been close()d concurrently. This behaviour totally depends on the timing of the peer's close() and reading sk->sk_shutdown, and taking the lock does not play a role. Let's drop the lock from __unix_dgram_recvmsg() and use READ_ONCE(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250702223606.1054680-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-08net: splice: Drop unused @gfpMichal Luczaj
Since its introduction in commit 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES"), skb_splice_from_iter() never used the @gfp argument. Remove it and adapt callers. No functional change intended. Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Michal Luczaj <mhal@rbox.co> Link: https://patch.msgid.link/20250702-splice-drop-unused-v3-2-55f68b60d2b7@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-04af_unix: stash pidfs dentry when neededAlexander Mikhalitsyn
We need to ensure that pidfs dentry is allocated when we meet any struct pid for the first time. This will allows us to open pidfd even after the task it corresponds to is reaped. Basically, we need to identify all places where we fill skb/scm_cookie with struct pid reference for the first time and call pidfs_register_pid(). Tricky thing here is that we have a few places where this happends depending on what userspace is doing: - [__scm_replace_pid()] explicitly sending an SCM_CREDENTIALS message and specified pid in a numeric format - [unix_maybe_add_creds()] enabled SO_PASSCRED/SO_PASSPIDFD but didn't send SCM_CREDENTIALS explicitly - [scm_send()] force_creds is true. Netlink case, we don't need to touch it. Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Leon Romanovsky <leon@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christian Brauner <brauner@kernel.org> Cc: Kuniyuki Iwashima <kuniyu@google.com> Cc: Lennart Poettering <mzxreary@0pointer.de> Cc: Luca Boccassi <bluca@debian.org> Cc: David Rheinsberg <david@readahead.eu> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/20250703222314.309967-6-aleksandr.mikhalitsyn@canonical.com Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-07-04af_unix/scm: fix whitespace errorsAlexander Mikhalitsyn
Fix whitespace/formatting errors. Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Leon Romanovsky <leon@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christian Brauner <brauner@kernel.org> Cc: Kuniyuki Iwashima <kuniyu@google.com> Cc: Lennart Poettering <mzxreary@0pointer.de> Cc: Luca Boccassi <bluca@debian.org> Cc: David Rheinsberg <david@readahead.eu> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/20250703222314.309967-5-aleksandr.mikhalitsyn@canonical.com Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-07-04af_unix: introduce unix_skb_to_scm helperAlexander Mikhalitsyn
Instead of open-coding let's consolidate this logic in a separate helper. This will simplify further changes. Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Leon Romanovsky <leon@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christian Brauner <brauner@kernel.org> Cc: Kuniyuki Iwashima <kuniyu@google.com> Cc: Lennart Poettering <mzxreary@0pointer.de> Cc: Luca Boccassi <bluca@debian.org> Cc: David Rheinsberg <david@readahead.eu> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/20250703222314.309967-3-aleksandr.mikhalitsyn@canonical.com Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-07-04af_unix: rework unix_maybe_add_creds() to allow sleepAlexander Mikhalitsyn
As a preparation for the next patches we need to allow sleeping in unix_maybe_add_creds() and also return err. Currently, we can't do that as unix_maybe_add_creds() is being called under unix_state_lock(). There is no need for this, really. So let's move call sites of this helper a bit and do necessary function signature changes. Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Leon Romanovsky <leon@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christian Brauner <brauner@kernel.org> Cc: Kuniyuki Iwashima <kuniyu@google.com> Cc: Lennart Poettering <mzxreary@0pointer.de> Cc: Luca Boccassi <bluca@debian.org> Cc: David Rheinsberg <david@readahead.eu> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/20250703222314.309967-2-aleksandr.mikhalitsyn@canonical.com Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.16-rc4). Conflicts: Documentation/netlink/specs/mptcp_pm.yaml 9e6dd4c256d0 ("netlink: specs: mptcp: replace underscores with dashes in names") ec362192aa9e ("netlink: specs: fix up indentation errors") https://lore.kernel.org/20250626122205.389c2cd4@canb.auug.org.au Adjacent changes: Documentation/netlink/specs/fou.yaml 791a9ed0a40d ("netlink: specs: fou: replace underscores with dashes in names") 880d43ca9aa4 ("netlink: specs: clean up spaces in brackets") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-24af_unix: Don't set -ECONNRESET for consumed OOB skb.Kuniyuki Iwashima
Christian Brauner reported that even after MSG_OOB data is consumed, calling close() on the receiver socket causes the peer's recv() to return -ECONNRESET: 1. send() and recv() an OOB data. >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) >>> s1.send(b'x', MSG_OOB) 1 >>> s2.recv(1, MSG_OOB) b'x' 2. close() for s2 sets ECONNRESET to s1->sk_err even though s2 consumed the OOB data >>> s2.close() >>> s1.recv(10, MSG_DONTWAIT) ... ConnectionResetError: [Errno 104] Connection reset by peer Even after being consumed, the skb holding the OOB 1-byte data stays in the recv queue to mark the OOB boundary and break recv() at that point. This must be considered while close()ing a socket. Let's skip the leading consumed OOB skb while checking the -ECONNRESET condition in unix_release_sock(). Fixes: 314001f0bf92 ("af_unix: Add OOB support") Reported-by: Christian Brauner <brauner@kernel.org> Closes: https://lore.kernel.org/netdev/20250529-sinkt-abfeuern-e7b08200c6b0@brauner/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Christian Brauner <brauner@kernel.org> Link: https://patch.msgid.link/20250619041457.1132791-4-kuni1840@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-06-24af_unix: Don't leave consecutive consumed OOB skbs.Kuniyuki Iwashima
Jann Horn reported a use-after-free in unix_stream_read_generic(). The following sequences reproduce the issue: $ python3 from socket import * s1, s2 = socketpair(AF_UNIX, SOCK_STREAM) s1.send(b'x', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'y', MSG_OOB) s2.recv(1, MSG_OOB) # leave a consumed OOB skb s1.send(b'z', MSG_OOB) s2.recv(1) # recv 'z' illegally s2.recv(1, MSG_OOB) # access 'z' skb (use-after-free) Even though a user reads OOB data, the skb holding the data stays on the recv queue to mark the OOB boundary and break the next recv(). After the last send() in the scenario above, the sk2's recv queue has 2 leading consumed OOB skbs and 1 real OOB skb. Then, the following happens during the next recv() without MSG_OOB 1. unix_stream_read_generic() peeks the first consumed OOB skb 2. manage_oob() returns the next consumed OOB skb 3. unix_stream_read_generic() fetches the next not-yet-consumed OOB skb 4. unix_stream_read_generic() reads and frees the OOB skb , and the last recv(MSG_OOB) triggers KASAN splat. The 3. above occurs because of the SO_PEEK_OFF code, which does not expect unix_skb_len(skb) to be 0, but this is true for such consumed OOB skbs. while (skip >= unix_skb_len(skb)) { skip -= unix_skb_len(skb); skb = skb_peek_next(skb, &sk->sk_receive_queue); ... } In addition to this use-after-free, there is another issue that ioctl(SIOCATMARK) does not function properly with consecutive consumed OOB skbs. So, nothing good comes out of such a situation. Instead of complicating manage_oob(), ioctl() handling, and the next ECONNRESET fix by introducing a loop for consecutive consumed OOB skbs, let's not leave such consecutive OOB unnecessarily. Now, while receiving an OOB skb in unix_stream_recv_urg(), if its previous skb is a consumed OOB skb, it is freed. [0]: BUG: KASAN: slab-use-after-free in unix_stream_read_actor (net/unix/af_unix.c:3027) Read of size 4 at addr ffff888106ef2904 by task python3/315 CPU: 2 UID: 0 PID: 315 Comm: python3 Not tainted 6.16.0-rc1-00407-gec315832f6f9 #8 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:409 mm/kasan/report.c:521) kasan_report (mm/kasan/report.c:636) unix_stream_read_actor (net/unix/af_unix.c:3027) unix_stream_read_generic (net/unix/af_unix.c:2708 net/unix/af_unix.c:2847) unix_stream_recvmsg (net/unix/af_unix.c:3048) sock_recvmsg (net/socket.c:1063 (discriminator 20) net/socket.c:1085 (discriminator 20)) __sys_recvfrom (net/socket.c:2278) __x64_sys_recvfrom (net/socket.c:2291 (discriminator 1) net/socket.c:2287 (discriminator 1) net/socket.c:2287 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f8911fcea06 Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 RSP: 002b:00007fffdb0dccb0 EFLAGS: 00000202 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007fffdb0dcdc8 RCX: 00007f8911fcea06 RDX: 0000000000000001 RSI: 00007f8911a5e060 RDI: 0000000000000006 RBP: 00007fffdb0dccd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000202 R12: 00007f89119a7d20 R13: ffffffffc4653600 R14: 0000000000000000 R15: 0000000000000000 </TASK> Allocated by task 315: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) __kasan_slab_alloc (mm/kasan/common.c:348) kmem_cache_alloc_node_noprof (./include/linux/kasan.h:250 mm/slub.c:4148 mm/slub.c:4197 mm/slub.c:4249) __alloc_skb (net/core/skbuff.c:660 (discriminator 4)) alloc_skb_with_frags (./include/linux/skbuff.h:1336 net/core/skbuff.c:6668) sock_alloc_send_pskb (net/core/sock.c:2993) unix_stream_sendmsg (./include/net/sock.h:1847 net/unix/af_unix.c:2256 net/unix/af_unix.c:2418) __sys_sendto (net/socket.c:712 (discriminator 20) net/socket.c:727 (discriminator 20) net/socket.c:2226 (discriminator 20)) __x64_sys_sendto (net/socket.c:2233 (discriminator 1) net/socket.c:2229 (discriminator 1) net/socket.c:2229 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 315: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) kasan_save_free_info (mm/kasan/generic.c:579 (discriminator 1)) __kasan_slab_free (mm/kasan/common.c:271) kmem_cache_free (mm/slub.c:4643 (discriminator 3) mm/slub.c:4745 (discriminator 3)) unix_stream_read_generic (net/unix/af_unix.c:3010) unix_stream_recvmsg (net/unix/af_unix.c:3048) sock_recvmsg (net/socket.c:1063 (discriminator 20) net/socket.c:1085 (discriminator 20)) __sys_recvfrom (net/socket.c:2278) __x64_sys_recvfrom (net/socket.c:2291 (discriminator 1) net/socket.c:2287 (discriminator 1) net/socket.c:2287 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) The buggy address belongs to the object at ffff888106ef28c0 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 68 bytes inside of freed 224-byte region [ffff888106ef28c0, ffff888106ef29a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888106ef3cc0 pfn:0x106ef2 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff8881001d28c0 ffffea000422fe00 0000000000000004 raw: ffff888106ef3cc0 0000000080190010 00000000f5000000 0000000000000000 head: 0200000000000040 ffff8881001d28c0 ffffea000422fe00 0000000000000004 head: ffff888106ef3cc0 0000000080190010 00000000f5000000 0000000000000000 head: 0200000000000001 ffffea00041bbc81 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888106ef2800: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888106ef2880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888106ef2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888106ef2980: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff888106ef2a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 314001f0bf92 ("af_unix: Add OOB support") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jann Horn <jannh@google.com> Link: https://patch.msgid.link/20250619041457.1132791-2-kuni1840@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-06-23net: remove sock_i_uid()Eric Dumazet
Difference between sock_i_uid() and sk_uid() is that after sock_orphan(), sock_i_uid() returns GLOBAL_ROOT_UID while sk_uid() returns the last cached sk->sk_uid value. None of sock_i_uid() callers care about this. Use sk_uid() which is much faster and inlined. Note that diag/dump users are calling sock_i_ino() and can not see the full benefit yet. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://patch.msgid.link/20250620133001.4090592-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-19pidfs: remove pidfs_{get,put}_pid()Christian Brauner
Now that we stash persistent information in struct pid there's no need to play volatile games with pinning struct pid via dentries in pidfs. Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-8-98f3456fd552@kernel.org Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-12af_unix: Allow passing cred for embryo without SO_PASSCRED/SO_PASSPIDFD.Kuniyuki Iwashima
Before the cited commit, the kernel unconditionally embedded SCM credentials to skb for embryo sockets even when both the sender and listener disabled SO_PASSCRED and SO_PASSPIDFD. Now, the credentials are added to skb only when configured by the sender or the listener. However, as reported in the link below, it caused a regression for some programs that assume credentials are included in every skb, but sometimes not now. The only problematic scenario would be that a socket starts listening before setting the option. Then, there will be 2 types of non-small race window, where a client can send skb without credentials, which the peer receives as an "invalid" message (and aborts the connection it seems ?): Client Server ------ ------ s1.listen() <-- No SO_PASS{CRED,PIDFD} s2.connect() s2.send() <-- w/o cred s1.setsockopt(SO_PASS{CRED,PIDFD}) s2.send() <-- w/ cred or Client Server ------ ------ s1.listen() <-- No SO_PASS{CRED,PIDFD} s2.connect() s2.send() <-- w/o cred s3, _ = s1.accept() <-- Inherit cred options s2.send() <-- w/o cred but not set yet s3.setsockopt(SO_PASS{CRED,PIDFD}) s2.send() <-- w/ cred It's unfortunate that buggy programs depend on the behaviour, but let's restore the previous behaviour. Fixes: 3f84d577b79d ("af_unix: Inherit sk_flags at connect().") Reported-by: Jacek Łuczak <difrost.kernel@gmail.com> Closes: https://lore.kernel.org/all/68d38b0b-1666-4974-85d4-15575789c8d4@gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Tested-by: Christian Heusel <christian@heusel.eu> Tested-by: André Almeida <andrealmeid@igalia.com> Tested-by: Jacek Łuczak <difrost.kernel@gmail.com> Link: https://patch.msgid.link/20250611202758.3075858-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-28Merge tag 'net-next-6.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core: - Implement the Device Memory TCP transmit path, allowing zero-copy data transmission on top of TCP from e.g. GPU memory to the wire. - Move all the IPv6 routing tables management outside the RTNL scope, under its own lock and RCU. The route control path is now 3x times faster. - Convert queue related netlink ops to instance lock, reducing again the scope of the RTNL lock. This improves the control plane scalability. - Refactor the software crc32c implementation, removing unneeded abstraction layers and improving significantly the related micro-benchmarks. - Optimize the GRO engine for UDP-tunneled traffic, for a 10% performance improvement in related stream tests. - Cover more per-CPU storage with local nested BH locking; this is a prep work to remove the current per-CPU lock in local_bh_disable() on PREMPT_RT. - Introduce and use nlmsg_payload helper, combining buffer bounds verification with accessing payload carried by netlink messages. Netfilter: - Rewrite the procfs conntrack table implementation, improving considerably the dump performance. A lot of user-space tools still use this interface. - Implement support for wildcard netdevice in netdev basechain and flowtables. - Integrate conntrack information into nft trace infrastructure. - Export set count and backend name to userspace, for better introspection. BPF: - BPF qdisc support: BPF-qdisc can be implemented with BPF struct_ops programs and can be controlled in similar way to traditional qdiscs using the "tc qdisc" command. - Refactor the UDP socket iterator, addressing long standing issues WRT duplicate hits or missed sockets. Protocols: - Improve TCP receive buffer auto-tuning and increase the default upper bound for the receive buffer; overall this improves the single flow maximum thoughput on 200Gbs link by over 60%. - Add AFS GSSAPI security class to AF_RXRPC; it provides transport security for connections to the AFS fileserver and VL server. - Improve TCP multipath routing, so that the sources address always matches the nexthop device. - Introduce SO_PASSRIGHTS for AF_UNIX, to allow disabling SCM_RIGHTS, and thus preventing DoS caused by passing around problematic FDs. - Retire DCCP socket. DCCP only receives updates for bugs, and major distros disable it by default. Its removal allows for better organisation of TCP fields to reduce the number of cache lines hit in the fast path. - Extend TCP drop-reason support to cover PAWS checks. Driver API: - Reorganize PTP ioctl flag support to require an explicit opt-in for the drivers, avoiding the problem of drivers not rejecting new unsupported flags. - Converted several device drivers to timestamping APIs. - Introduce per-PHY ethtool dump helpers, improving the support for dump operations targeting PHYs. Tests and tooling: - Add support for classic netlink in user space C codegen, so that ynl-c can now read, create and modify links, routes addresses and qdisc layer configuration. - Add ynl sub-types for binary attributes, allowing ynl-c to output known struct instead of raw binary data, clarifying the classic netlink output. - Extend MPTCP selftests to improve the code-coverage. - Add tests for XDP tail adjustment in AF_XDP. New hardware / drivers: - OpenVPN virtual driver: offload OpenVPN data channels processing to the kernel-space, increasing the data transfer throughput WRT the user-space implementation. - Renesas glue driver for the gigabit ethernet RZ/V2H(P) SoC. - Broadcom asp-v3.0 ethernet driver. - AMD Renoir ethernet device. - ReakTek MT9888 2.5G ethernet PHY driver. - Aeonsemi 10G C45 PHYs driver. Drivers: - Ethernet high-speed NICs: - nVidia/Mellanox (mlx5): - refactor the steering table handling to significantly reduce the amount of memory used - add support for complex matches in H/W flow steering - improve flow streeing error handling - convert to netdev instance locking - Intel (100G, ice, igb, ixgbe, idpf): - ice: add switchdev support for LLDP traffic over VF - ixgbe: add firmware manipulation and regions devlink support - igb: introduce support for frame transmission premption - igb: adds persistent NAPI configuration - idpf: introduce RDMA support - idpf: add initial PTP support - Meta (fbnic): - extend hardware stats coverage - add devlink dev flash support - Broadcom (bnxt): - add support for RX-side device memory TCP - Wangxun (txgbe): - implement support for udp tunnel offload - complete PTP and SRIOV support for AML 25G/10G devices - Ethernet NICs embedded and virtual: - Google (gve): - add device memory TCP TX support - Amazon (ena): - support persistent per-NAPI config - Airoha: - add H/W support for L2 traffic offload - add per flow stats for flow offloading - RealTek (rtl8211): add support for WoL magic packet - Synopsys (stmmac): - dwmac-socfpga 1000BaseX support - add Loongson-2K3000 support - introduce support for hardware-accelerated VLAN stripping - Broadcom (bcmgenet): - expose more H/W stats - Freescale (enetc, dpaa2-eth): - enetc: add MAC filter, VLAN filter RSS and loopback support - dpaa2-eth: convert to H/W timestamping APIs - vxlan: convert FDB table to rhashtable, for better scalabilty - veth: apply qdisc backpressure on full ring to reduce TX drops - Ethernet switches: - Microchip (kzZ88x3): add ETS scheduler support - Ethernet PHYs: - RealTek (rtl8211): - add support for WoL magic packet - add support for PHY LEDs - CAN: - Adds RZ/G3E CANFD support to the rcar_canfd driver. - Preparatory work for CAN-XL support. - Add self-tests framework with support for CAN physical interfaces. - WiFi: - mac80211: - scan improvements with multi-link operation (MLO) - Qualcomm (ath12k): - enable AHB support for IPQ5332 - add monitor interface support to QCN9274 - add multi-link operation support to WCN7850 - add 802.11d scan offload support to WCN7850 - monitor mode for WCN7850, better 6 GHz regulatory - Qualcomm (ath11k): - restore hibernation support - MediaTek (mt76): - WiFi-7 improvements - implement support for mt7990 - Intel (iwlwifi): - enhanced multi-link single-radio (EMLSR) support on 5 GHz links - rework device configuration - RealTek (rtw88): - improve throughput for RTL8814AU - RealTek (rtw89): - add multi-link operation support - STA/P2P concurrency improvements - support different SAR configs by antenna - Bluetooth: - introduce HCI Driver protocol - btintel_pcie: do not generate coredump for diagnostic events - btusb: add HCI Drv commands for configuring altsetting - btusb: add RTL8851BE device 0x0bda:0xb850 - btusb: add new VID/PID 13d3/3584 for MT7922 - btusb: add new VID/PID 13d3/3630 and 13d3/3613 for MT7925 - btnxpuart: implement host-wakeup feature" * tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1611 commits) selftests/bpf: Fix bpf selftest build warning selftests: netfilter: Fix skip of wildcard interface test net: phy: mscc: Stop clearing the the UDPv4 checksum for L2 frames net: openvswitch: Fix the dead loop of MPLS parse calipso: Don't call calipso functions for AF_INET sk. selftests/tc-testing: Add a test for HFSC eltree double add with reentrant enqueue behaviour on netem net_sched: hfsc: Address reentrant enqueue adding class to eltree twice octeontx2-pf: QOS: Refactor TC_HTB_LEAF_DEL_LAST callback octeontx2-pf: QOS: Perform cache sync on send queue teardown net: mana: Add support for Multi Vports on Bare metal net: devmem: ncdevmem: remove unused variable net: devmem: ksft: upgrade rx test to send 1K data net: devmem: ksft: add 5 tuple FS support net: devmem: ksft: add exit_wait to make rx test pass net: devmem: ksft: add ipv4 support net: devmem: preserve sockc_err page_pool: fix ugly page_pool formatting net: devmem: move list_add to net_devmem_bind_dmabuf. selftests: netfilter: nft_queue.sh: include file transfer duration in log message net: phy: mscc: Fix memory leak when using one step timestamping ...
2025-05-23af_unix: Introduce SO_PASSRIGHTS.Kuniyuki Iwashima
As long as recvmsg() or recvmmsg() is used with cmsg, it is not possible to avoid receiving file descriptors via SCM_RIGHTS. This behaviour has occasionally been flagged as problematic, as it can be (ab)used to trigger DoS during close(), for example, by passing a FUSE-controlled fd or a hung NFS fd. For instance, as noted on the uAPI Group page [0], an untrusted peer could send a file descriptor pointing to a hung NFS mount and then close it. Once the receiver calls recvmsg() with msg_control, the descriptor is automatically installed, and then the responsibility for the final close() now falls on the receiver, which may result in blocking the process for a long time. Regarding this, systemd calls cmsg_close_all() [1] after each recvmsg() to close() unwanted file descriptors sent via SCM_RIGHTS. However, this cannot work around the issue at all, because the final fput() may still occur on the receiver's side once sendmsg() with SCM_RIGHTS succeeds. Also, even filtering by LSM at recvmsg() does not work for the same reason. Thus, we need a better way to refuse SCM_RIGHTS at sendmsg(). Let's introduce SO_PASSRIGHTS to disable SCM_RIGHTS. Note that this option is enabled by default for backward compatibility. Link: https://uapi-group.org/kernel-features/#disabling-reception-of-scm_rights-for-af_unix-sockets #[0] Link: https://github.com/systemd/systemd/blob/v257.5/src/basic/fd-util.c#L612-L628 #[1] Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-23af_unix: Inherit sk_flags at connect().Kuniyuki Iwashima
For SOCK_STREAM embryo sockets, the SO_PASS{CRED,PIDFD,SEC} options are inherited from the parent listen()ing socket. Currently, this inheritance happens at accept(), because these attributes were stored in sk->sk_socket->flags and the struct socket is not allocated until accept(). This leads to unintentional behaviour. When a peer sends data to an embryo socket in the accept() queue, unix_maybe_add_creds() embeds credentials into the skb, even if neither the peer nor the listener has enabled these options. If the option is enabled, the embryo socket receives the ancillary data after accept(). If not, the data is silently discarded. This conservative approach works for SO_PASS{CRED,PIDFD,SEC}, but would not for SO_PASSRIGHTS; once an SCM_RIGHTS with a hung file descriptor was sent, it'd be game over. To avoid this, we will need to preserve SOCK_PASSRIGHTS even on embryo sockets. Commit aed6ecef55d7 ("af_unix: Save listener for embryo socket.") made it possible to access the parent's flags in sendmsg() via unix_sk(other)->listener->sk->sk_socket->flags, but this introduces an unnecessary condition that is irrelevant for most sockets, accept()ed sockets and clients. Therefore, we moved SOCK_PASSXXX into struct sock. Let’s inherit sk->sk_scm_recv_flags at connect() to avoid receiving SCM_RIGHTS on embryo sockets created from a parent with SO_PASSRIGHTS=0. Note that the parent socket is locked in connect() so we don't need READ_ONCE() for sk_scm_recv_flags. Now, we can remove !other->sk_socket check in unix_maybe_add_creds() to avoid slow SOCK_PASS{CRED,PIDFD} handling for embryo sockets created from a parent with SO_PASS{CRED,PIDFD}=0. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-23af_unix: Move SOCK_PASS{CRED,PIDFD,SEC} to struct sock.Kuniyuki Iwashima
As explained in the next patch, SO_PASSRIGHTS would have a problem if we assigned a corresponding bit to socket->flags, so it must be managed in struct sock. Mixing socket->flags and sk->sk_flags for similar options will look confusing, and sk->sk_flags does not have enough space on 32bit system. Also, as mentioned in commit 16e572626961 ("af_unix: dont send SCM_CREDENTIALS by default"), SOCK_PASSCRED and SOCK_PASSPID handling is known to be slow, and managing the flags in struct socket cannot avoid that for embryo sockets. Let's move SOCK_PASS{CRED,PIDFD,SEC} to struct sock. While at it, other SOCK_XXX flags in net.h are grouped as enum. Note that assign_bit() was atomic, so the writer side is moved down after lock_sock() in setsockopt(), but the bit is only read once in sendmsg() and recvmsg(), so lock_sock() is not needed there. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-23af_unix: Don't pass struct socket to maybe_add_creds().Kuniyuki Iwashima
We will move SOCK_PASS{CRED,PIDFD,SEC} from struct socket.flags to struct sock for better handling with SOCK_PASSRIGHTS. Then, we don't need to access struct socket in maybe_add_creds(). Let's pass struct sock to maybe_add_creds() and its caller queue_oob(). While at it, we append the unix_ prefix and fix double spaces around the pid assignment. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-23af_unix: Factorise test_bit() for SOCK_PASSCRED and SOCK_PASSPIDFD.Kuniyuki Iwashima
Currently, the same checks for SOCK_PASSCRED and SOCK_PASSPIDFD are scattered across many places. Let's centralise the bit tests to make the following changes cleaner. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-21coredump: add coredump socketChristian Brauner
Coredumping currently supports two modes: (1) Dumping directly into a file somewhere on the filesystem. (2) Dumping into a pipe connected to a usermode helper process spawned as a child of the system_unbound_wq or kthreadd. For simplicity I'm mostly ignoring (1). There's probably still some users of (1) out there but processing coredumps in this way can be considered adventurous especially in the face of set*id binaries. The most common option should be (2) by now. It works by allowing userspace to put a string into /proc/sys/kernel/core_pattern like: |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h The "|" at the beginning indicates to the kernel that a pipe must be used. The path following the pipe indicator is a path to a binary that will be spawned as a usermode helper process. Any additional parameters pass information about the task that is generating the coredump to the binary that processes the coredump. In the example core_pattern shown above systemd-coredump is spawned as a usermode helper. There's various conceptual consequences of this (non-exhaustive list): - systemd-coredump is spawned with file descriptor number 0 (stdin) connected to the read-end of the pipe. All other file descriptors are closed. That specifically includes 1 (stdout) and 2 (stderr). This has already caused bugs because userspace assumed that this cannot happen (Whether or not this is a sane assumption is irrelevant.). - systemd-coredump will be spawned as a child of system_unbound_wq. So it is not a child of any userspace process and specifically not a child of PID 1. It cannot be waited upon and is in a weird hybrid upcall which are difficult for userspace to control correctly. - systemd-coredump is spawned with full kernel privileges. This necessitates all kinds of weird privilege dropping excercises in userspace to make this safe. - A new usermode helper has to be spawned for each crashing process. This series adds a new mode: (3) Dumping into an AF_UNIX socket. Userspace can set /proc/sys/kernel/core_pattern to: @/path/to/coredump.socket The "@" at the beginning indicates to the kernel that an AF_UNIX coredump socket will be used to process coredumps. The coredump socket must be located in the initial mount namespace. When a task coredumps it opens a client socket in the initial network namespace and connects to the coredump socket. - The coredump server uses SO_PEERPIDFD to get a stable handle on the connected crashing task. The retrieved pidfd will provide a stable reference even if the crashing task gets SIGKILLed while generating the coredump. - By setting core_pipe_limit non-zero userspace can guarantee that the crashing task cannot be reaped behind it's back and thus process all necessary information in /proc/<pid>. The SO_PEERPIDFD can be used to detect whether /proc/<pid> still refers to the same process. The core_pipe_limit isn't used to rate-limit connections to the socket. This can simply be done via AF_UNIX sockets directly. - The pidfd for the crashing task will grow new information how the task coredumps. - The coredump server should mark itself as non-dumpable. - A container coredump server in a separate network namespace can simply bind to another well-know address and systemd-coredump fowards coredumps to the container. - Coredumps could in the future also be handled via per-user/session coredump servers that run only with that users privileges. The coredump server listens on the coredump socket and accepts a new coredump connection. It then retrieves SO_PEERPIDFD for the client, inspects uid/gid and hands the accepted client to the users own coredump handler which runs with the users privileges only (It must of coure pay close attention to not forward crashing suid binaries.). The new coredump socket will allow userspace to not have to rely on usermode helpers for processing coredumps and provides a safer way to handle them instead of relying on super privileged coredumping helpers that have and continue to cause significant CVEs. This will also be significantly more lightweight since no fork()+exec() for the usermodehelper is required for each crashing process. The coredump server in userspace can e.g., just keep a worker pool. Link: https://lore.kernel.org/20250516-work-coredump-socket-v8-4-664f3caf2516@kernel.org Acked-by: Luca Boccassi <luca.boccassi@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Reviewed-by: Jann Horn <jannh@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-26net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pidChristian Brauner
SO_PEERPIDFD currently doesn't support handing out pidfds if the sk->sk_peer_pid thread-group leader has already been reaped. In this case it currently returns EINVAL. Userspace still wants to get a pidfd for a reaped process to have a stable handle it can pass on. This is especially useful now that it is possible to retrieve exit information through a pidfd via the PIDFD_GET_INFO ioctl()'s PIDFD_INFO_EXIT flag. Another summary has been provided by David in [1]: > A pidfd can outlive the task it refers to, and thus user-space must > already be prepared that the task underlying a pidfd is gone at the time > they get their hands on the pidfd. For instance, resolving the pidfd to > a PID via the fdinfo must be prepared to read `-1`. > > Despite user-space knowing that a pidfd might be stale, several kernel > APIs currently add another layer that checks for this. In particular, > SO_PEERPIDFD returns `EINVAL` if the peer-task was already reaped, > but returns a stale pidfd if the task is reaped immediately after the > respective alive-check. > > This has the unfortunate effect that user-space now has two ways to > check for the exact same scenario: A syscall might return > EINVAL/ESRCH/... *or* the pidfd might be stale, even though there is no > particular reason to distinguish both cases. This also propagates > through user-space APIs, which pass on pidfds. They must be prepared to > pass on `-1` *or* the pidfd, because there is no guaranteed way to get a > stale pidfd from the kernel. > Userspace must already deal with a pidfd referring to a reaped task as > the task may exit and get reaped at any time will there are still many > pidfds referring to it. In order to allow handing out reaped pidfd SO_PEERPIDFD needs to ensure that PIDFD_INFO_EXIT information is available whenever a pidfd for a reaped task is created by PIDFD_INFO_EXIT. The uapi promises that reaped pidfds are only handed out if it is guaranteed that the caller sees the exit information: TEST_F(pidfd_info, success_reaped) { struct pidfd_info info = { .mask = PIDFD_INFO_CGROUPID | PIDFD_INFO_EXIT, }; /* * Process has already been reaped and PIDFD_INFO_EXIT been set. * Verify that we can retrieve the exit status of the process. */ ASSERT_EQ(ioctl(self->child_pidfd4, PIDFD_GET_INFO, &info), 0); ASSERT_FALSE(!!(info.mask & PIDFD_INFO_CREDS)); ASSERT_TRUE(!!(info.mask & PIDFD_INFO_EXIT)); ASSERT_TRUE(WIFEXITED(info.exit_code)); ASSERT_EQ(WEXITSTATUS(info.exit_code), 0); } To hand out pidfds for reaped processes we thus allocate a pidfs entry for the relevant sk->sk_peer_pid at the time the sk->sk_peer_pid is stashed and drop it when the socket is destroyed. This guarantees that exit information will always be recorded for the sk->sk_peer_pid task and we can hand out pidfds for reaped processes. Link: https://lore.kernel.org/lkml/20230807085203.819772-1-david@readahead.eu [1] Link: https://lore.kernel.org/20250425-work-pidfs-net-v2-2-450a19461e75@kernel.org Reviewed-by: David Rheinsberg <david@readahead.eu> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-10af_unix: Remove unix_unhash()Michal Luczaj
Dummy unix_unhash() was introduced for sockmap in commit 94531cfcbe79 ("af_unix: Add unix_stream_proto for sockmap"), but there's no need to implement it anymore. ->unhash() is only called conditionally: in unix_shutdown() since commit d359902d5c35 ("af_unix: Fix NULL pointer bug in unix_shutdown"), and in BPF proto's sock_map_unhash() since commit 5b4a79ba65a1 ("bpf, sockmap: Don't let sock_map_{close,destroy,unhash} call itself"). Remove it. Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250409-cleanup-drop-unix-unhash-v1-1-1659e5b8ee84@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-26unix: fix up for "apparmor: add fine grained af_unix mediation"Stephen Rothwell
After merging the apparmor tree, today's linux-next build (x86_64 allmodconfig) failed like this: security/apparmor/af_unix.c: In function 'unix_state_double_lock': security/apparmor/af_unix.c:627:17: error: implicit declaration of function 'unix_state_lock'; did you mean 'unix_state_double_lock'? [-Wimplicit-function-declaration] 627 | unix_state_lock(sk1); | ^~~~~~~~~~~~~~~ | unix_state_double_lock security/apparmor/af_unix.c: In function 'unix_state_double_unlock': security/apparmor/af_unix.c:642:17: error: implicit declaration of function 'unix_state_unlock'; did you mean 'unix_state_double_lock'? [-Wimplicit-function-declaration] 642 | unix_state_unlock(sk1); | ^~~~~~~~~~~~~~~~~ | unix_state_double_lock Caused by commit c05e705812d1 ("apparmor: add fine grained af_unix mediation") interacting with commit 84960bf24031 ("af_unix: Move internal definitions to net/unix/.") from the net-next tree. Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://patch.msgid.link/20250326150148.72d9138d@canb.auug.org.au Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25af_unix: Clean up #include under net/unix/.Kuniyuki Iwashima
net/unix/*.c include many unnecessary header files (rtnetlink.h, netdevice.h, etc). Let's clean them up. af_unix.c: +uapi/linux/sockios.h : Only exist under include/uapi +uapi/linux/termios.h : Only exist under include/uapi -linux/freezer.h : No longer use freezable_schedule_timeout() -linux/in.h : No ipv4_is_XXX() etc -linux/module.h : No longer support CONFIG_UNIX=m -linux/netdevice.h : No dev used -linux/rtnetlink.h : Not part of rtnetlink API -linux/signal.h : signal_pending() is defined in sched/signal.h -linux/stat.h : No struct stat used -net/checksum.h : CHECKSUM_UNNECESSARY is defined in skbuff.h diag.c: +linux/dcache.h : struct dentry in sk_diag_dump_vfs() +linux/user_namespace.h : struct user_namespace in sk_diag_dump_uid() +uapi/linux/unix_diag.h : Only exist under include/uapi/ garbage.c: +linux/list.h : struct unix_{vertex,edge}, etc +linux/workqueue.h : DECLARE_WORK(unix_gc_work, ...) -linux/file.h : No fget() etc -linux/kernel.h : No cond_resched() etc -linux/netdevice.h : No dev used -linux/proc_fs.h : No procfs provided -linux/string.h : No memcpy(), kmemdup(), etc sysctl_net_unix.c: +linux/string.h : kmemdup() +net/net_namespace.h : struct net, net_eq() -linux/mm.h : slab.h is enough Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250318034934.86708-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25af_unix: Explicitly include headers for non-pointer struct fields.Kuniyuki Iwashima
include/net/af_unix.h indirectly includes some definitions for structs. Let's include such headers explicitly. linux/atomic.h : scm_stat.nr_fds linux/net.h : unix_sock.peer_wq linux/path.h : unix_sock.path linux/spinlock.h : unix_sock.lock linux/wait.h : unix_sock.peer_wake uapi/linux/un.h : unix_address.name[] linux/socket.h is removed as the structs there are not used directly, and linux/un.h is clarified with uapi as un.h only exists under include/uapi. While at it, duplicate headers are removed from .c files. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250318034934.86708-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25af_unix: Move internal definitions to net/unix/.Kuniyuki Iwashima
net/af_unix.h is included by core and some LSMs, but most definitions need not be. Let's move struct unix_{vertex,edge} to net/unix/garbage.c and other definitions to net/unix/af_unix.h. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250318034934.86708-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-25af_unix: Sort headers.Kuniyuki Iwashima
This is a prep patch to make the following changes cleaner. No functional change intended. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250318034934.86708-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.14-rc5). Conflicts: drivers/net/ethernet/cadence/macb_main.c fa52f15c745c ("net: cadence: macb: Synchronize stats calculations") 75696dd0fd72 ("net: cadence: macb: Convert to get_stats64") https://lore.kernel.org/20250224125848.68ee63e5@canb.auug.org.au Adjacent changes: drivers/net/ethernet/intel/ice/ice_sriov.c 79990cf5e7ad ("ice: Fix deinitializing VF in error path") a203163274a4 ("ice: simplify VF MSI-X managing") net/ipv4/tcp.c 18912c520674 ("tcp: devmem: don't write truncated dmabuf CMSGs to userspace") 297d389e9e5b ("net: prefix devmem specific helpers") net/mptcp/subflow.c 8668860b0ad3 ("mptcp: reset when MPTCP opts are dropped after join") c3349a22c200 ("mptcp: consolidate subflow cleanup") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-26af_unix: Fix memory leak in unix_dgram_sendmsg()Adrian Huang
After running the 'sendmsg02' program of Linux Test Project (LTP), kmemleak reports the following memory leak: # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff888243866800 (size 2048): comm "sendmsg02", pid 67, jiffies 4294903166 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 5e 00 00 00 00 00 00 00 ........^....... 01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............ backtrace (crc 7e96a3f2): kmemleak_alloc+0x56/0x90 kmem_cache_alloc_noprof+0x209/0x450 sk_prot_alloc.constprop.0+0x60/0x160 sk_alloc+0x32/0xc0 unix_create1+0x67/0x2b0 unix_create+0x47/0xa0 __sock_create+0x12e/0x200 __sys_socket+0x6d/0x100 __x64_sys_socket+0x1b/0x30 x64_sys_call+0x7e1/0x2140 do_syscall_64+0x54/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e Commit 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") defers sock_put() in the error handling path. However, it fails to account for the condition 'msg->msg_namelen != 0', resulting in a memory leak when the code jumps to the 'lookup' label. Fix issue by calling sock_put() if 'msg->msg_namelen != 0' is met. Fixes: 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Acked-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250225021457.1824-1-ahuang12@lenovo.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-20af_unix: Fix undefined 'other' errorPurva Yeshi
Fix an issue with the sparse static analysis tool where an "undefined 'other'" error occurs due to `__releases(&unix_sk(other)->lock)` being placed before 'other' is in scope. Remove the `__releases()` annotation from the `unix_wait_for_peer()` function to eliminate the sparse error. The annotation references `other` before it is declared, leading to a false positive error during static analysis. Since AF_UNIX does not use sparse annotations, this annotation is unnecessary and does not impact functionality. Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250218141045.38947-1-purvayeshi550@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Use consume_skb() in connect() and sendmsg().Kuniyuki Iwashima
This is based on Donald Hunter's patch. These functions could fail for various reasons, sometimes triggering kfree_skb(). * unix_stream_connect() : connect() * unix_stream_sendmsg() : sendmsg() * queue_oob() : sendmsg(MSG_OOB) * unix_dgram_sendmsg() : sendmsg() Such kfree_skb() is tied to the errno of connect() and sendmsg(), and we need not define skb drop reasons. Let's use consume_skb() not to churn kfree_skb() events. Link: https://lore.kernel.org/netdev/eb30b164-7f86-46bf-a5d3-0f8bda5e9398@redhat.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-10-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Reuse out_pipe label in unix_stream_sendmsg().Kuniyuki Iwashima
This is a follow-up of commit d460b04bc452 ("af_unix: Clean up error paths in unix_stream_sendmsg()."). If we initialise skb with NULL in unix_stream_sendmsg(), we can reuse the existing out_pipe label for the SEND_SHUTDOWN check. Let's rename it and adjust the existing label as out_pipe_lock. While at it, size and data_len are moved to the while loop scope. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-9-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_dgram_disconnected().Kuniyuki Iwashima
unix_dgram_disconnected() is called from two places: 1. when a connect()ed socket dis-connect()s or re-connect()s to another socket 2. when sendmsg() fails because the peer socket that the client has connect()ed to has been close()d Then, the client's recv queue is purged to remove all messages from the old peer socket. Let's define a new drop reason for that case. # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> >>> # s1 has a message from s2 >>> s1, s2 = socketpair(AF_UNIX, SOCK_DGRAM) >>> s2.send(b'hello world') >>> >>> # re-connect() drops the message from s2 >>> s3 = socket(AF_UNIX, SOCK_DGRAM) >>> s3.bind('') >>> s1.connect(s3.getsockname()) # cat /sys/kernel/tracing/trace_pipe python3-250 ... kfree_skb: ... location=skb_queue_purge_reason+0xdc/0x110 reason: UNIX_DISCONNECT Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-8-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_stream_read_skb().Kuniyuki Iwashima
unix_stream_read_skb() is called when BPF SOCKMAP reads some data from a socket in the map. SOCKMAP does not support MSG_OOB, and reading OOB results in a drop. Let's set drop reasons respectively. * SOCKET_CLOSE : the socket in SOCKMAP was close()d * UNIX_SKIP_OOB : OOB was read from the socket in SOCKMAP Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in manage_oob().Kuniyuki Iwashima
AF_UNIX SOCK_STREAM socket supports MSG_OOB. When OOB data is sent to a socket, recv() will break at that point. If the next recv() does not have MSG_OOB, the normal data following the OOB data is returned. Then, the OOB skb is dropped. Let's define a new drop reason for that case in manage_oob(). # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX) >>> s1.send(b'a', MSG_OOB) >>> s1.send(b'b') >>> s2.recv(2) b'b' # cat /sys/kernel/tracing/trace_pipe ... python3-223 ... kfree_skb: ... location=unix_stream_read_generic+0x59e/0xc20 reason: UNIX_SKIP_OOB Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in __unix_gc().Kuniyuki Iwashima
Inflight file descriptors by SCM_RIGHTS hold references to the struct file. AF_UNIX sockets could hold references to each other, forming reference cycles. Once such sockets are close()d without the fd recv()ed, they will be unaccessible from userspace but remain in kernel. __unix_gc() garbage-collects skb with the dead file descriptors and frees them by __skb_queue_purge(). Let's set SKB_DROP_REASON_SOCKET_CLOSE there. # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> from array import array >>> >>> # Create a reference cycle >>> s1 = socket(AF_UNIX, SOCK_DGRAM) >>> s1.bind('') >>> s1.sendmsg([b"nop"], [(SOL_SOCKET, SCM_RIGHTS, array("i", [s1.fileno()]))], 0, s1.getsockname()) >>> s1.close() >>> >>> # Trigger GC >>> s2 = socket(AF_UNIX) >>> s2.close() # cat /sys/kernel/tracing/trace_pipe ... kworker/u16:2-42 ... kfree_skb: ... location=__unix_gc+0x4ad/0x580 reason: SOCKET_CLOSE Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_sock_destructor().Kuniyuki Iwashima
unix_sock_destructor() is called as sk->sk_destruct() just before the socket is actually freed. Let's use SKB_DROP_REASON_SOCKET_CLOSE for skb_queue_purge(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_release_sock().Kuniyuki Iwashima
unix_release_sock() is called when the last refcnt of struct file is released. Let's define a new drop reason SKB_DROP_REASON_SOCKET_CLOSE and set it for kfree_skb() in unix_release_sock(). # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX) >>> s1.send(b'hello world') >>> s2.close() # cat /sys/kernel/tracing/trace_pipe ... python3-280 ... kfree_skb: ... protocol=0 location=unix_release_sock+0x260/0x420 reason: SOCKET_CLOSE To be precise, unix_release_sock() is also called for a new child socket in unix_stream_connect() when something fails, but the new sk does not have skb in the recv queue then and no event is logged. Note that only tcp_inbound_ao_hash() uses a similar drop reason, SKB_DROP_REASON_TCP_CLOSE, and this can be generalised later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-19af_unix: Add a prompt to CONFIG_AF_UNIX_OOBFlorent Revest
This makes it possible to disable the MSG_OOB support in .config. Signed-off-by: Florent Revest <revest@chromium.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241218143334.1507465-1-revest@chromium.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-17af_unix: Remove unix_our_peer().Kuniyuki Iwashima
unix_our_peer() is used only in unix_may_send(). Let's inline it in unix_may_send(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up error paths in unix_dgram_sendmsg().Kuniyuki Iwashima
The error path is complicated in unix_dgram_sendmsg() because there are two timings when other could be non-NULL: when it's fetched from unix_peer_get() and when it's looked up by unix_find_other(). Let's move unix_peer_get() to the else branch for unix_find_other() and clean up the error paths. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up SOCK_DEAD error paths in unix_dgram_sendmsg().Kuniyuki Iwashima
When other has SOCK_DEAD in unix_dgram_sendmsg(), we hold unix_state_lock() for the sender socket first. However, we do not need it for sk->sk_type. Let's move the lock down a bit. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().Kuniyuki Iwashima
When other has SOCK_DEAD in unix_dgram_sendmsg(), we call sock_put() for it first and then set NULL to other before jumping to the error path. This is to skip sock_put() in the error path. Let's not set NULL to other and defer the sock_put() to the error path to clean up the labels later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>