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2020-10-05rxrpc: Fix server keyring leakDavid Howells
If someone calls setsockopt() twice to set a server key keyring, the first keyring is leaked. Fix it to return an error instead if the server key keyring is already set. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-05rxrpc: The server keyring isn't network-namespacedDavid Howells
The keyring containing the server's tokens isn't network-namespaced, so it shouldn't be looked up with a network namespace. It is expected to be owned specifically by the server, so namespacing is unnecessary. Fixes: a58946c158a0 ("keys: Pass the network namespace into request_key mechanism") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-05rxrpc: Fix accept on a connection that need securingDavid Howells
When a new incoming call arrives at an userspace rxrpc socket on a new connection that has a security class set, the code currently pushes it onto the accept queue to hold a ref on it for the socket. This doesn't work, however, as recvmsg() pops it off, notices that it's in the SERVER_SECURING state and discards the ref. This means that the call runs out of refs too early and the kernel oopses. By contrast, a kernel rxrpc socket manually pre-charges the incoming call pool with calls that already have user call IDs assigned, so they are ref'd by the call tree on the socket. Change the mode of operation for userspace rxrpc server sockets to work like this too. Although this is a UAPI change, server sockets aren't currently functional. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-05rxrpc: Fix some missing _bh annotations on locking conn->state_lockDavid Howells
conn->state_lock may be taken in softirq mode, but a previous patch replaced an outer lock in the response-packet event handling code, and lost the _bh from that when doing so. Fix this by applying the _bh annotation to the state_lock locking. Fixes: a1399f8bb033 ("rxrpc: Call channels should have separate call number spaces") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-05rxrpc: Downgrade the BUG() for unsupported token type in rxrpc_read()David Howells
If rxrpc_read() (which allows KEYCTL_READ to read a key), sees a token of a type it doesn't recognise, it can BUG in a couple of places, which is unnecessary as it can easily get back to userspace. Fix this to print an error message instead. Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)") Signed-off-by: David Howells <dhowells@redhat.com>
2020-10-05rxrpc: Fix rxkad token xdr encodingMarc Dionne
The session key should be encoded with just the 8 data bytes and no length; ENCODE_DATA precedes it with a 4 byte length, which confuses some existing tools that try to parse this format. Add an ENCODE_BYTES macro that does not include a length, and use it for the key. Also adjust the expected length. Note that commit 774521f353e1d ("rxrpc: Fix an assertion in rxrpc_read()") had fixed a BUG by changing the length rather than fixing the encoding. The original length was correct. Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)") Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2020-09-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi Kivilinna. 2) Fix loss of RTT samples in rxrpc, from David Howells. 3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu. 4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka. 5) We disable BH for too lokng in sctp_get_port_local(), add a cond_resched() here as well, from Xin Long. 6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu. 7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from Yonghong Song. 8) Missing of_node_put() in mt7530 DSA driver, from Sumera Priyadarsini. 9) Fix crash in bnxt_fw_reset_task(), from Michael Chan. 10) Fix geneve tunnel checksumming bug in hns3, from Yi Li. 11) Memory leak in rxkad_verify_response, from Dinghao Liu. 12) In tipc, don't use smp_processor_id() in preemptible context. From Tuong Lien. 13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu. 14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter. 15) Fix ABI mismatch between driver and firmware in nfp, from Louis Peens. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits) net/smc: fix sock refcounting in case of termination net/smc: reset sndbuf_desc if freed net/smc: set rx_off for SMCR explicitly net/smc: fix toleration of fake add_link messages tg3: Fix soft lockup when tg3_reset_task() fails. doc: net: dsa: Fix typo in config code sample net: dp83867: Fix WoL SecureOn password nfp: flower: fix ABI mismatch between driver and firmware tipc: fix shutdown() of connectionless socket ipv6: Fix sysctl max for fib_multipath_hash_policy drivers/net/wan/hdlc: Change the default of hard_header_len to 0 net: gemini: Fix another missing clk_disable_unprepare() in probe net: bcmgenet: fix mask check in bcmgenet_validate_flow() amd-xgbe: Add support for new port mode net: usb: dm9601: Add USB ID of Keenetic Plus DSL vhost: fix typo in error message net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init() pktgen: fix error message with wrong function name net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode cxgb4: fix thermal zone device registration ...
2020-08-27rxrpc: Fix memory leak in rxkad_verify_response()Dinghao Liu
Fix a memory leak in rxkad_verify_response() whereby the response buffer doesn't get freed if we fail to allocate a ticket buffer. Fixes: ef68622da9cc ("rxrpc: Handle temporary errors better in rxkad security") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-20rxrpc: Make rxrpc_kernel_get_srtt() indicate validityDavid Howells
Fix rxrpc_kernel_get_srtt() to indicate the validity of the returned smoothed RTT. If we haven't had any valid samples yet, the SRTT isn't useful. Fixes: c410bf01933e ("rxrpc: Fix the excessive initial retransmission timeout") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20rxrpc: Fix loss of RTT samples due to interposed ACKDavid Howells
The Rx protocol has a mechanism to help generate RTT samples that works by a client transmitting a REQUESTED-type ACK when it receives a DATA packet that has the REQUEST_ACK flag set. The peer, however, may interpose other ACKs before transmitting the REQUESTED-ACK, as can be seen in the following trace excerpt: rxrpc_tx_data: c=00000044 DATA d0b5ece8:00000001 00000001 q=00000001 fl=07 rxrpc_rx_ack: c=00000044 00000001 PNG r=00000000 f=00000002 p=00000000 n=0 rxrpc_rx_ack: c=00000044 00000002 REQ r=00000001 f=00000002 p=00000001 n=0 ... DATA packet 1 (q=xx) has REQUEST_ACK set (bit 1 of fl=xx). The incoming ping (labelled PNG) hard-acks the request DATA packet (f=xx exceeds the sequence number of the DATA packet), causing it to be discarded from the Tx ring. The ACK that was requested (labelled REQ, r=xx references the serial of the DATA packet) comes after the ping, but the sk_buff holding the timestamp has gone and the RTT sample is lost. This is particularly noticeable on RPC calls used to probe the service offered by the peer. A lot of peers end up with an unknown RTT because we only ever sent a single RPC. This confuses the server rotation algorithm. Fix this by caching the information about the outgoing packet in RTT calculations in the rxrpc_call struct rather than looking in the Tx ring. A four-deep buffer is maintained and both REQUEST_ACK-flagged DATA and PING-ACK transmissions are recorded in there. When the appropriate response ACK is received, the buffer is checked for a match and, if found, an RTT sample is recorded. If a received ACK refers to a packet with a later serial number than an entry in the cache, that entry is presumed lost and the entry is made available to record a new transmission. ACKs types other than REQUESTED-type and PING-type cause any matching sample to be cancelled as they don't necessarily represent a useful measurement. If there's no space in the buffer on ping/data transmission, the sample base is discarded. Fixes: 50235c4b5a2f ("rxrpc: Obtain RTT data by requesting ACKs on DATA packets") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-20rxrpc: Keep the ACK serial in a var in rxrpc_input_ack()David Howells
Keep the ACK serial number in a variable in rxrpc_input_ack() as it's used frequently. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Resolved kernel/bpf/btf.c using instructions from merge commit 69138b34a7248d2396ab85c8652e20c0c39beaba Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30rxrpc: Fix race between recvmsg and sendmsg on immediate call failureDavid Howells
There's a race between rxrpc_sendmsg setting up a call, but then failing to send anything on it due to an error, and recvmsg() seeing the call completion occur and trying to return the state to the user. An assertion fails in rxrpc_recvmsg() because the call has already been released from the socket and is about to be released again as recvmsg deals with it. (The recvmsg_q queue on the socket holds a ref, so there's no problem with use-after-free.) We also have to be careful not to end up reporting an error twice, in such a way that both returns indicate to userspace that the user ID supplied with the call is no longer in use - which could cause the client to malfunction if it recycles the user ID fast enough. Fix this by the following means: (1) When sendmsg() creates a call after the point that the call has been successfully added to the socket, don't return any errors through sendmsg(), but rather complete the call and let recvmsg() retrieve them. Make sendmsg() return 0 at this point. Further calls to sendmsg() for that call will fail with ESHUTDOWN. Note that at this point, we haven't send any packets yet, so the server doesn't yet know about the call. (2) If sendmsg() returns an error when it was expected to create a new call, it means that the user ID wasn't used. (3) Mark the call disconnected before marking it completed to prevent an oops in rxrpc_release_call(). (4) recvmsg() will then retrieve the error and set MSG_EOR to indicate that the user ID is no longer known by the kernel. An oops like the following is produced: kernel BUG at net/rxrpc/recvmsg.c:605! ... RIP: 0010:rxrpc_recvmsg+0x256/0x5ae ... Call Trace: ? __init_waitqueue_head+0x2f/0x2f ____sys_recvmsg+0x8a/0x148 ? import_iovec+0x69/0x9c ? copy_msghdr_from_user+0x5c/0x86 ___sys_recvmsg+0x72/0xaa ? __fget_files+0x22/0x57 ? __fget_light+0x46/0x51 ? fdget+0x9/0x1b do_recvmmsg+0x15e/0x232 ? _raw_spin_unlock+0xa/0xb ? vtime_delta+0xf/0x25 __x64_sys_recvmmsg+0x2c/0x2f do_syscall_64+0x4c/0x78 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 357f5ef64628 ("rxrpc: Call rxrpc_release_call() on error in rxrpc_new_client_call()") Reported-by: syzbot+b54969381df354936d96@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The UDP reuseport conflict was a little bit tricky. The net-next code, via bpf-next, extracted the reuseport handling into a helper so that the BPF sk lookup code could invoke it. At the same time, the logic for reuseport handling of unconnected sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace which changed the logic to carry on the reuseport result into the rest of the lookup loop if we do not return immediately. This requires moving the reuseport_has_conns() logic into the callers. While we are here, get rid of inline directives as they do not belong in foo.c files. The other changes were cases of more straightforward overlapping modifications. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24net: pass a sockptr_t into ->setsockoptChristoph Hellwig
Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154] Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20rxrpc: Fix sendmsg() returning EPIPE due to recvmsg() returning ENODATADavid Howells
rxrpc_sendmsg() returns EPIPE if there's an outstanding error, such as if rxrpc_recvmsg() indicating ENODATA if there's nothing for it to read. Change rxrpc_recvmsg() to return EAGAIN instead if there's nothing to read as this particular error doesn't get stored in ->sk_err by the networking core. Also change rxrpc_sendmsg() so that it doesn't fail with delayed receive errors (there's no way for it to report which call, if any, the error was caused by). Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13net: rxrpc: kerneldoc fixesAndrew Lunn
Simple fixes which require no deep knowledge of the code. Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-20rxrpc: Fix notification call on completion of discarded callsDavid Howells
When preallocated service calls are being discarded, they're passed to ->discard_new_call() to have the caller clean up any attached higher-layer preallocated pieces before being marked completed. However, the act of marking them completed now invokes the call's notification function - which causes a problem because that function might assume that the previously freed pieces of memory are still there. Fix this by setting a dummy notification function on the socket after calling ->discard_new_call(). This results in the following kasan message when the kafs module is removed. ================================================================== BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 fs/afs/rxrpc.c:707 Write of size 1 at addr ffff8880946c39e4 by task kworker/u4:1/21 CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 afs_wake_up_async_call+0x6aa/0x770 fs/afs/rxrpc.c:707 rxrpc_notify_socket+0x1db/0x5d0 net/rxrpc/recvmsg.c:40 __rxrpc_set_call_completion.part.0+0x172/0x410 net/rxrpc/recvmsg.c:76 __rxrpc_call_completed net/rxrpc/recvmsg.c:112 [inline] rxrpc_call_completed+0xca/0xf0 net/rxrpc/recvmsg.c:111 rxrpc_discard_prealloc+0x781/0xab0 net/rxrpc/call_accept.c:233 rxrpc_listen+0x147/0x360 net/rxrpc/af_rxrpc.c:245 afs_close_socket+0x95/0x320 fs/afs/rxrpc.c:110 afs_net_exit+0x1bc/0x310 fs/afs/main.c:155 ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186 cleanup_net+0x511/0xa50 net/core/net_namespace.c:603 process_one_work+0x965/0x1690 kernel/workqueue.c:2269 worker_thread+0x96/0xe10 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 6820: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] afs_alloc_call+0x55/0x630 fs/afs/rxrpc.c:141 afs_charge_preallocation+0xe9/0x2d0 fs/afs/rxrpc.c:757 afs_open_socket+0x292/0x360 fs/afs/rxrpc.c:92 afs_net_init+0xa6c/0xe30 fs/afs/main.c:125 ops_init+0xaf/0x420 net/core/net_namespace.c:151 setup_net+0x2de/0x860 net/core/net_namespace.c:341 copy_net_ns+0x293/0x590 net/core/net_namespace.c:482 create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:231 ksys_unshare+0x43d/0x8e0 kernel/fork.c:2983 __do_sys_unshare kernel/fork.c:3051 [inline] __se_sys_unshare kernel/fork.c:3049 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3049 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 21: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 afs_put_call+0x585/0xa40 fs/afs/rxrpc.c:190 rxrpc_discard_prealloc+0x764/0xab0 net/rxrpc/call_accept.c:230 rxrpc_listen+0x147/0x360 net/rxrpc/af_rxrpc.c:245 afs_close_socket+0x95/0x320 fs/afs/rxrpc.c:110 afs_net_exit+0x1bc/0x310 fs/afs/main.c:155 ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186 cleanup_net+0x511/0xa50 net/core/net_namespace.c:603 process_one_work+0x965/0x1690 kernel/workqueue.c:2269 worker_thread+0x96/0xe10 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff8880946c3800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 484 bytes inside of 1024-byte region [ffff8880946c3800, ffff8880946c3c00) The buggy address belongs to the page: page:ffffea000251b0c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002546508 ffffea00024fa248 ffff8880aa000c40 raw: 0000000000000000 ffff8880946c3000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880946c3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880946c3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880946c3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880946c3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880946c3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: syzbot+d3eccef36ddbd02713e9@syzkaller.appspotmail.com Fixes: 5ac0d62226a0 ("rxrpc: Fix missing notification") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-17rxrpc: Fix afs large storage transmission performance dropDavid Howells
Commit 2ad6691d988c, which moved the modification of the status annotation for a packet in the Tx buffer prior to the retransmission moved the state clearance, but managed to lose the bit that set it to UNACK. Consequently, if a retransmission occurs, the packet is accidentally changed to the ACK state (ie. 0) by masking it off, which means that the packet isn't counted towards the tally of newly-ACK'd packets if it gets hard-ACK'd. This then prevents the congestion control algorithm from recovering properly. Fix by reinstating the change of state to UNACK. Spotted by the generic/460 xfstest. Fixes: 2ad6691d988c ("rxrpc: Fix race between incoming ACK parser and retransmitter") Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-17rxrpc: Fix handling of rwind from an ACK packetDavid Howells
The handling of the receive window size (rwind) from a received ACK packet is not correct. The rxrpc_input_ackinfo() function currently checks the current Tx window size against the rwind from the ACK to see if it has changed, but then limits the rwind size before storing it in the tx_winsize member and, if it increased, wake up the transmitting process. This means that if rwind > RXRPC_RXTX_BUFF_SIZE - 1, this path will always be followed. Fix this by limiting rwind before we compare it to tx_winsize. The effect of this can be seen by enabling the rxrpc_rx_rwind_change tracepoint. Fixes: 702f2ac87a9a ("rxrpc: Wake up the transmitter if Rx window size increases on the peer") Signed-off-by: David Howells <dhowells@redhat.com>
2020-06-11rxrpc: Fix race between incoming ACK parser and retransmitterDavid Howells
There's a race between the retransmission code and the received ACK parser. The problem is that the retransmission loop has to drop the lock under which it is iterating through the transmission buffer in order to transmit a packet, but whilst the lock is dropped, the ACK parser can crank the Tx window round and discard the packets from the buffer. The retransmission code then updated the annotations for the wrong packet and a later retransmission thought it had to retransmit a packet that wasn't there, leading to a NULL pointer dereference. Fix this by: (1) Moving the annotation change to before we drop the lock prior to transmission. This means we can't vary the annotation depending on the outcome of the transmission, but that's fine - we'll retransmit again later if it failed now. (2) Skipping the packet if the skb pointer is NULL. The following oops was seen: BUG: kernel NULL pointer dereference, address: 000000000000002d Workqueue: krxrpcd rxrpc_process_call RIP: 0010:rxrpc_get_skb+0x14/0x8a ... Call Trace: rxrpc_resend+0x331/0x41e ? get_vtime_delta+0x13/0x20 rxrpc_process_call+0x3c0/0x4ac process_one_work+0x18f/0x27f worker_thread+0x1a3/0x247 ? create_worker+0x17d/0x17d kthread+0xe6/0xeb ? kthread_delayed_work_timer_fn+0x83/0x83 ret_from_fork+0x1f/0x30 Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-08Merge tag 'rxrpc-fixes-20200605' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs David Howells says: ==================== rxrpc: Fix hang due to missing notification Here's a fix for AF_RXRPC. Occasionally calls hang because there are circumstances in which rxrpc generate a notification when a call is completed - primarily because initial packet transmission failed and the call was killed off and an error returned. But the AFS filesystem driver doesn't check this under all circumstances, expecting failure to be delivered by asynchronous notification. There are two patches: the first moves the problematic bits out-of-line and the second contains the fix. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-05Merge tag 'afs-next-20200604' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull AFS updates from David Howells: "There's some core VFS changes which affect a couple of filesystems: - Make the inode hash table RCU safe and providing some RCU-safe accessor functions. The search can then be done without taking the inode_hash_lock. Care must be taken because the object may be being deleted and no wait is made. - Allow iunique() to avoid taking the inode_hash_lock. - Allow AFS's callback processing to avoid taking the inode_hash_lock when using the inode table to find an inode to notify. - Improve Ext4's time updating. Konstantin Khlebnikov said "For now, I've plugged this issue with try-lock in ext4 lazy time update. This solution is much better." Then there's a set of changes to make a number of improvements to the AFS driver: - Improve callback (ie. third party change notification) processing by: (a) Relying more on the fact we're doing this under RCU and by using fewer locks. This makes use of the RCU-based inode searching outlined above. (b) Moving to keeping volumes in a tree indexed by volume ID rather than a flat list. (c) Making the server and volume records logically part of the cell. This means that a server record now points directly at the cell and the tree of volumes is there. This removes an N:M mapping table, simplifying things. - Improve keeping NAT or firewall channels open for the server callbacks to reach the client by actively polling the fileserver on a timed basis, instead of only doing it when we have an operation to process. - Improving detection of delayed or lost callbacks by including the parent directory in the list of file IDs to be queried when doing a bulk status fetch from lookup. We can then check to see if our copy of the directory has changed under us without us getting notified. - Determine aliasing of cells (such as a cell that is pointed to be a DNS alias). This allows us to avoid having ambiguity due to apparently different cells using the same volume and file servers. - Improve the fileserver rotation to do more probing when it detects that all of the addresses to a server are listed as non-responsive. It's possible that an address that previously stopped responding has become responsive again. Beyond that, lay some foundations for making some calls asynchronous: - Turn the fileserver cursor struct into a general operation struct and hang the parameters off of that rather than keeping them in local variables and hang results off of that rather than the call struct. - Implement some general operation handling code and simplify the callers of operations that affect a volume or a volume component (such as a file). Most of the operation is now done by core code. - Operations are supplied with a table of operations to issue different variants of RPCs and to manage the completion, where all the required data is held in the operation object, thereby allowing these to be called from a workqueue. - Put the standard "if (begin), while(select), call op, end" sequence into a canned function that just emulates the current behaviour for now. There are also some fixes interspersed: - Don't let the EACCES from ICMP6 mapping reach the user as such, since it's confusing as to whether it's a filesystem error. Convert it to EHOSTUNREACH. - Don't use the epoch value acquired through probing a server. If we have two servers with the same UUID but in different cells, it's hard to draw conclusions from them having different epoch values. - Don't interpret the argument to the CB.ProbeUuid RPC as a fileserver UUID and look up a fileserver from it. - Deal with servers in different cells having the same UUIDs. In the event that a CB.InitCallBackState3 RPC is received, we have to break the callback promises for every server record matching that UUID. - Don't let afs_statfs return values that go below 0. - Don't use running fileserver probe state to make server selection and address selection decisions on. Only make decisions on final state as the running state is cleared at the start of probing" Acked-by: Al Viro <viro@zeniv.linux.org.uk> (fs/inode.c part) * tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (27 commits) afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly afs: Show more a bit more server state in /proc/net/afs/servers afs: Don't use probe running state to make decisions outside probe code afs: Fix afs_statfs() to not let the values go below zero afs: Fix the by-UUID server tree to allow servers with the same UUID afs: Reorganise volume and server trees to be rooted on the cell afs: Add a tracepoint to track the lifetime of the afs_volume struct afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op afs: Detect cell aliases 2 - Cells with no root volumes afs: Detect cell aliases 1 - Cells with root volumes afs: Implement client support for the YFSVL.GetCellName RPC op afs: Retain more of the VLDB record for alias detection afs: Fix handling of CB.ProbeUuid cache manager op afs: Don't get epoch from a server because it may be ambiguous afs: Build an abstraction around an "operation" concept afs: Rename struct afs_fs_cursor to afs_operation afs: Remove the error argument from afs_protocol_error() afs: Set error flag rather than return error from file status decode afs: Make callback processing more efficient. afs: Show more information in /proc/net/afs/servers ...
2020-06-05rxrpc: Fix missing notificationDavid Howells
Under some circumstances, rxrpc will fail a transmit a packet through the underlying UDP socket (ie. UDP sendmsg returns an error). This may result in a call getting stuck. In the instance being seen, where AFS tries to send a probe to the Volume Location server, tracepoints show the UDP Tx failure (in this case returing error 99 EADDRNOTAVAIL) and then nothing more: afs_make_vl_call: c=0000015d VL.GetCapabilities rxrpc_call: c=0000015d NWc u=1 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000dd89ee8a rxrpc_call: c=0000015d Gus u=2 sp=rxrpc_new_client_call+0x14f/0x580 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d SEE u=2 sp=rxrpc_activate_one_channel+0x7b/0x1c0 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d CON u=2 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000e20e4b08 rxrpc_tx_fail: c=0000015d r=1 ret=-99 CallDataNofrag The problem is that if the initial packet fails and the retransmission timer hasn't been started, the call is set to completed and an error is returned from rxrpc_send_data_packet() to rxrpc_queue_packet(). Though rxrpc_instant_resend() is called, this does nothing because the call is marked completed. So rxrpc_notify_socket() isn't called and the error is passed back up to rxrpc_send_data(), rxrpc_kernel_send_data() and thence to afs_make_call() and afs_vl_get_capabilities() where it is simply ignored because it is assumed that the result of a probe will be collected asynchronously. Fileserver probing is similarly affected via afs_fs_get_capabilities(). Fix this by always issuing a notification in __rxrpc_set_call_completion() if it shifts a call to the completed state, even if an error is also returned to the caller through the function return value. Also put in a little bit of optimisation to avoid taking the call state_lock and disabling softirqs if the call is already in the completed state and remove some now redundant rxrpc_notify_socket() calls. Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Reported-by: Gerry Seidman <gerry@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
2020-06-05rxrpc: Move the call completion handling out of lineDavid Howells
Move the handling of call completion out of line so that the next patch can add more code in that area. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
2020-05-31rxrpc: Adjust /proc/net/rxrpc/calls to display call->debug_id not user_IDDavid Howells
The user ID value isn't actually much use - and leaks a kernel pointer or a userspace value - so replace it with the call debug ID, which appears in trace points. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-31rxrpc: Map the EACCES error produced by some ICMP6 to EHOSTUNREACHDavid Howells
Map the EACCES error that is produced by some ICMP6 packets to EHOSTUNREACH when we get them as EACCES has other meanings within a filesystem context. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-28rxrpc: add rxrpc_sock_set_min_security_levelChristoph Hellwig
Add a helper to directly set the RXRPC_MIN_SECURITY_LEVEL sockopt from kernel space without going through a fake uaccess. Thanks to David Howells for the documentation updates. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv6: add ip6_sock_set_recverrChristoph Hellwig
Add a helper to directly set the IPV6_RECVERR sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_mtu_discoverChristoph Hellwig
Add a helper to directly set the IP_MTU_DISCOVER sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> [rxrpc bits] Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_recverrChristoph Hellwig
Add a helper to directly set the IP_RECVERR sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28net: add sock_enable_timestampsChristoph Hellwig
Add a helper to directly enable timestamps instead of setting the SO_TIMESTAMP* sockopts from kernel space and going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The MSCC bug fix in 'net' had to be slightly adjusted because the register accesses are done slightly differently in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-23rxrpc: Fix a memory leak in rxkad_verify_response()Qiushi Wu
A ticket was not released after a call of the function "rxkad_decrypt_ticket" failed. Thus replace the jump target "temporary_error_free_resp" by "temporary_error_free_ticket". Fixes: 8c2f826dc3631 ("rxrpc: Don't put crypto buffers on the stack") Signed-off-by: Qiushi Wu <wu000273@umn.edu> Signed-off-by: David Howells <dhowells@redhat.com> cc: Markus Elfring <Markus.Elfring@web.de>
2020-05-20rxrpc: Fix ack discardDavid Howells
The Rx protocol has a "previousPacket" field in it that is not handled in the same way by all protocol implementations. Sometimes it contains the serial number of the last DATA packet received, sometimes the sequence number of the last DATA packet received and sometimes the highest sequence number so far received. AF_RXRPC is using this to weed out ACKs that are out of date (it's possible for ACK packets to get reordered on the wire), but this does not work with OpenAFS which will just stick the sequence number of the last packet seen into previousPacket. The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are timing out when partly sent. A trace was captured, with an additional tracepoint to show ACKs being discarded in rxrpc_input_ack(). Here's an excerpt showing the problem. 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09 A DATA packet with sequence number 00024499 has been transmitted (the "q=" field). ... 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2 The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence number 00024499, but did see seq 0002449a (previousPacket, shown as "p=", skipped the number, but firstPacket, "f=", which shows the bottom of the window is set at that point). 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS* The packet has been retransmitted. Retransmission recurs until the peer says it got the packet. 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6 More OOS ACKs indicate that the other packets that are already in the transmission pipeline are being received. The specific-ACK list is up to 6 ACKs and NAKs. ... 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS* 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32 At this point, the server's receive window is full (n=32) with presumably 1 NAK'd packet and 31 ACK'd packets. We can't transmit any more packets. 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS* 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25 And now we've received an ACK indicating that a DATA retransmission was received. 7 packets have been processed (the occupied part of the window moved, as indicated by f= and n=). 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8 However, the DLY ACK gets discarded because its previousPacket has gone backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the ACK at 52873.293850). We then end up in a continuous cycle of retransmit/discard. kafs fails to update its window because it's discarding the ACKs and can't transmit an extra packet that would clear the issue because the window is full. OpenAFS doesn't change the previousPacket value in the ACKs because no new DATA packets are received with a different previousPacket number. Fix this by altering the discard check to only discard an ACK based on previousPacket if there was no advance in the firstPacket. This allows us to transmit a new packet which will cause previousPacket to advance in the next ACK. The check, however, needs to allow for the possibility that previousPacket may actually have had the serial number placed in it instead - in which case it will go outside the window and we should ignore it. Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks") Reported-by: Dave Botsch <botsch@cnf.cornell.edu> Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-20rxrpc: Trace discarded ACKsDavid Howells
Add a tracepoint to track received ACKs that are discarded due to being outside of the Tx window. Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-11rxrpc: Fix the excessive initial retransmission timeoutDavid Howells
rxrpc currently uses a fixed 4s retransmission timeout until the RTT is sufficiently sampled. This can cause problems with some fileservers with calls to the cache manager in the afs filesystem being dropped from the fileserver because a packet goes missing and the retransmission timeout is greater than the call expiry timeout. Fix this by: (1) Copying the RTT/RTO calculation code from Linux's TCP implementation and altering it to fit rxrpc. (2) Altering the various users of the RTT to make use of the new SRTT value. (3) Replacing the use of rxrpc_resend_timeout to use the calculated RTO value instead (which is needed in jiffies), along with a backoff. Notes: (1) rxrpc provides RTT samples by matching the serial numbers on outgoing DATA packets that have the RXRPC_REQUEST_ACK set and PING ACK packets against the reference serial number in incoming REQUESTED ACK and PING-RESPONSE ACK packets. (2) Each packet that is transmitted on an rxrpc connection gets a new per-connection serial number, even for retransmissions, so an ACK can be cross-referenced to a specific trigger packet. This allows RTT information to be drawn from retransmitted DATA packets also. (3) rxrpc maintains the RTT/RTO state on the rxrpc_peer record rather than on an rxrpc_call because many RPC calls won't live long enough to generate more than one sample. (4) The calculated SRTT value is in units of 8ths of a microsecond rather than nanoseconds. The (S)RTT and RTO values are displayed in /proc/net/rxrpc/peers. Fixes: 17926a79320a ([AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both"") Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-30docs: networking: convert rxrpc.txt to ReSTMauro Carvalho Chehab
- add SPDX header; - adjust title markup; - use autonumbered list markups; - mark code blocks and literals as such; - mark tables as such; - adjust identation, whitespaces and blank lines where needed; - add to networking/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-14rxrpc: Fix DATA Tx to disable nofrag for UDP on AF_INET6 socketDavid Howells
Fix the DATA packet transmission to disable nofrag for UDPv4 on an AF_INET6 socket as well as UDPv6 when trying to transmit fragmentably. Without this, packets filled to the normal size used by the kernel AFS client of 1412 bytes be rejected by udp_sendmsg() with EMSGSIZE immediately. The ->sk_error_report() notification hook is called, but rxrpc doesn't generate a trace for it. This is a temporary fix; a more permanent solution needs to involve changing the size of the packets being filled in accordance with the MTU, which isn't currently done in AF_RXRPC. The reason for not doing so was that, barring the last packet in an rx jumbo packet, jumbos can only be assembled out of 1412-byte packets - and the plan was to construct jumbos on the fly at transmission time. Also, there's no point turning on IPV6_MTU_DISCOVER, since IPv6 has to engage in this anyway since fragmentation is only done by the sender. We can then condense the switch-statement in rxrpc_send_data_packet(). Fixes: 75b54cb57ca3 ("rxrpc: Add IPv6 support") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29KEYS: Don't write out to userspace while holding key semaphoreWaiman Long
A lockdep circular locking dependency report was seen when running a keyutils test: [12537.027242] ====================================================== [12537.059309] WARNING: possible circular locking dependency detected [12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE --------- - - [12537.125253] ------------------------------------------------------ [12537.153189] keyctl/25598 is trying to acquire lock: [12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0 [12537.208365] [12537.208365] but task is already holding lock: [12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12537.270476] [12537.270476] which lock already depends on the new lock. [12537.270476] [12537.307209] [12537.307209] the existing dependency chain (in reverse order) is: [12537.340754] [12537.340754] -> #3 (&type->lock_class){++++}: [12537.367434] down_write+0x4d/0x110 [12537.385202] __key_link_begin+0x87/0x280 [12537.405232] request_key_and_link+0x483/0xf70 [12537.427221] request_key+0x3c/0x80 [12537.444839] dns_query+0x1db/0x5a5 [dns_resolver] [12537.468445] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.496731] cifs_reconnect+0xe04/0x2500 [cifs] [12537.519418] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.546263] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.573551] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.601045] kthread+0x30c/0x3d0 [12537.617906] ret_from_fork+0x3a/0x50 [12537.636225] [12537.636225] -> #2 (root_key_user.cons_lock){+.+.}: [12537.664525] __mutex_lock+0x105/0x11f0 [12537.683734] request_key_and_link+0x35a/0xf70 [12537.705640] request_key+0x3c/0x80 [12537.723304] dns_query+0x1db/0x5a5 [dns_resolver] [12537.746773] dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs] [12537.775607] cifs_reconnect+0xe04/0x2500 [cifs] [12537.798322] cifs_readv_from_socket+0x461/0x690 [cifs] [12537.823369] cifs_read_from_socket+0xa0/0xe0 [cifs] [12537.847262] cifs_demultiplex_thread+0x311/0x2db0 [cifs] [12537.873477] kthread+0x30c/0x3d0 [12537.890281] ret_from_fork+0x3a/0x50 [12537.908649] [12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}: [12537.935225] __mutex_lock+0x105/0x11f0 [12537.954450] cifs_call_async+0x102/0x7f0 [cifs] [12537.977250] smb2_async_readv+0x6c3/0xc90 [cifs] [12538.000659] cifs_readpages+0x120a/0x1e50 [cifs] [12538.023920] read_pages+0xf5/0x560 [12538.041583] __do_page_cache_readahead+0x41d/0x4b0 [12538.067047] ondemand_readahead+0x44c/0xc10 [12538.092069] filemap_fault+0xec1/0x1830 [12538.111637] __do_fault+0x82/0x260 [12538.129216] do_fault+0x419/0xfb0 [12538.146390] __handle_mm_fault+0x862/0xdf0 [12538.167408] handle_mm_fault+0x154/0x550 [12538.187401] __do_page_fault+0x42f/0xa60 [12538.207395] do_page_fault+0x38/0x5e0 [12538.225777] page_fault+0x1e/0x30 [12538.243010] [12538.243010] -> #0 (&mm->mmap_sem){++++}: [12538.267875] lock_acquire+0x14c/0x420 [12538.286848] __might_fault+0x119/0x1b0 [12538.306006] keyring_read_iterator+0x7e/0x170 [12538.327936] assoc_array_subtree_iterate+0x97/0x280 [12538.352154] keyring_read+0xe9/0x110 [12538.370558] keyctl_read_key+0x1b9/0x220 [12538.391470] do_syscall_64+0xa5/0x4b0 [12538.410511] entry_SYSCALL_64_after_hwframe+0x6a/0xdf [12538.435535] [12538.435535] other info that might help us debug this: [12538.435535] [12538.472829] Chain exists of: [12538.472829] &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class [12538.472829] [12538.524820] Possible unsafe locking scenario: [12538.524820] [12538.551431] CPU0 CPU1 [12538.572654] ---- ---- [12538.595865] lock(&type->lock_class); [12538.613737] lock(root_key_user.cons_lock); [12538.644234] lock(&type->lock_class); [12538.672410] lock(&mm->mmap_sem); [12538.687758] [12538.687758] *** DEADLOCK *** [12538.687758] [12538.714455] 1 lock held by keyctl/25598: [12538.732097] #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220 [12538.770573] [12538.770573] stack backtrace: [12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G [12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015 [12538.881963] Call Trace: [12538.892897] dump_stack+0x9a/0xf0 [12538.907908] print_circular_bug.isra.25.cold.50+0x1bc/0x279 [12538.932891] ? save_trace+0xd6/0x250 [12538.948979] check_prev_add.constprop.32+0xc36/0x14f0 [12538.971643] ? keyring_compare_object+0x104/0x190 [12538.992738] ? check_usage+0x550/0x550 [12539.009845] ? sched_clock+0x5/0x10 [12539.025484] ? sched_clock_cpu+0x18/0x1e0 [12539.043555] __lock_acquire+0x1f12/0x38d0 [12539.061551] ? trace_hardirqs_on+0x10/0x10 [12539.080554] lock_acquire+0x14c/0x420 [12539.100330] ? __might_fault+0xc4/0x1b0 [12539.119079] __might_fault+0x119/0x1b0 [12539.135869] ? __might_fault+0xc4/0x1b0 [12539.153234] keyring_read_iterator+0x7e/0x170 [12539.172787] ? keyring_read+0x110/0x110 [12539.190059] assoc_array_subtree_iterate+0x97/0x280 [12539.211526] keyring_read+0xe9/0x110 [12539.227561] ? keyring_gc_check_iterator+0xc0/0xc0 [12539.249076] keyctl_read_key+0x1b9/0x220 [12539.266660] do_syscall_64+0xa5/0x4b0 [12539.283091] entry_SYSCALL_64_after_hwframe+0x6a/0xdf One way to prevent this deadlock scenario from happening is to not allow writing to userspace while holding the key semaphore. Instead, an internal buffer is allocated for getting the keys out from the read method first before copying them out to userspace without holding the lock. That requires taking out the __user modifier from all the relevant read methods as well as additional changes to not use any userspace write helpers. That is, 1) The put_user() call is replaced by a direct copy. 2) The copy_to_user() call is replaced by memcpy(). 3) All the fault handling code is removed. Compiling on a x86-64 system, the size of the rxrpc_read() function is reduced from 3795 bytes to 2384 bytes with this patch. Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
2020-03-13afs: Fix client call Rx-phase signal handlingDavid Howells
Fix the handling of signals in client rxrpc calls made by the afs filesystem. Ignore signals completely, leaving call abandonment or connection loss to be detected by timeouts inside AF_RXRPC. Allowing a filesystem call to be interrupted after the entire request has been transmitted and an abort sent means that the server may or may not have done the action - and we don't know. It may even be worse than that for older servers. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells <dhowells@redhat.com>
2020-03-13rxrpc: Fix sendmsg(MSG_WAITALL) handlingDavid Howells
Fix the handling of sendmsg() with MSG_WAITALL for userspace to round the timeout for when a signal occurs up to at least two jiffies as a 1 jiffy timeout may end up being effectively 0 if jiffies wraps at the wrong time. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells <dhowells@redhat.com>
2020-03-13rxrpc: Fix call interruptibility handlingDavid Howells
Fix the interruptibility of kernel-initiated client calls so that they're either only interruptible when they're waiting for a call slot to come available or they're not interruptible at all. Either way, they're not interruptible during transmission. This should help prevent StoreData calls from being interrupted when writeback is in progress. It doesn't, however, handle interruption during the receive phase. Userspace-initiated calls are still interruptable. After the signal has been handled, sendmsg() will return the amount of data copied out of the buffer and userspace can perform another sendmsg() call to continue transmission. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells <dhowells@redhat.com>
2020-03-13rxrpc: Abstract out the calculation of whether there's Tx spaceDavid Howells
Abstract out the calculation of there being sufficient Tx buffer space. This is reproduced several times in the rxrpc sendmsg code. Signed-off-by: David Howells <dhowells@redhat.com>
2020-02-07rxrpc: Fix call RCU cleanup using non-bh-safe locksDavid Howells
rxrpc_rcu_destroy_call(), which is called as an RCU callback to clean up a put call, calls rxrpc_put_connection() which, deep in its bowels, takes a number of spinlocks in a non-BH-safe way, including rxrpc_conn_id_lock and local->client_conns_lock. RCU callbacks, however, are normally called from softirq context, which can cause lockdep to notice the locking inconsistency. To get lockdep to detect this, it's necessary to have the connection cleaned up on the put at the end of the last of its calls, though normally the clean up is deferred. This can be induced, however, by starting a call on an AF_RXRPC socket and then closing the socket without reading the reply. Fix this by having rxrpc_rcu_destroy_call() punt the destruction to a workqueue if in softirq-mode and defer the destruction to process context. Note that another way to fix this could be to add a bunch of bh-disable annotations to the spinlocks concerned - and there might be more than just those two - but that means spending more time with BHs disabled. Note also that some of these places were covered by bh-disable spinlocks belonging to the rxrpc_transport object, but these got removed without the _bh annotation being retained on the next lock in. Fixes: 999b69f89241 ("rxrpc: Kill the client connection bundle concept") Reported-by: syzbot+d82f3ac8d87e7ccbb2c9@syzkaller.appspotmail.com Reported-by: syzbot+3f1fd6b8cbf8702d134e@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Hillf Danton <hdanton@sina.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-07rxrpc: Fix service call disconnectionDavid Howells
The recent patch that substituted a flag on an rxrpc_call for the connection pointer being NULL as an indication that a call was disconnected puts the set_bit in the wrong place for service calls. This is only a problem if a call is implicitly terminated by a new call coming in on the same connection channel instead of a terminating ACK packet. In such a case, rxrpc_input_implicit_end_call() calls __rxrpc_disconnect_call(), which is now (incorrectly) setting the disconnection bit, meaning that when rxrpc_release_call() is later called, it doesn't call rxrpc_disconnect_call() and so the call isn't removed from the peer's error distribution list and the list gets corrupted. KASAN finds the issue as an access after release on a call, but the position at which it occurs is confusing as it appears to be related to a different call (the call site is where the latter call is being removed from the error distribution list and either the next or pprev pointer points to a previously released call). Fix this by moving the setting of the flag from __rxrpc_disconnect_call() to rxrpc_disconnect_call() in the same place that the connection pointer was being cleared. Fixes: 5273a191dca6 ("rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-03rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnectDavid Howells
When a call is disconnected, the connection pointer from the call is cleared to make sure it isn't used again and to prevent further attempted transmission for the call. Unfortunately, there might be a daemon trying to use it at the same time to transmit a packet. Fix this by keeping call->conn set, but setting a flag on the call to indicate disconnection instead. Remove also the bits in the transmission functions where the conn pointer is checked and a ref taken under spinlock as this is now redundant. Fixes: 8d94aa381dab ("rxrpc: Calls shouldn't hold socket refs") Signed-off-by: David Howells <dhowells@redhat.com>
2020-01-30rxrpc: Fix missing active use pinning of rxrpc_local objectDavid Howells
The introduction of a split between the reference count on rxrpc_local objects and the usage count didn't quite go far enough. A number of kernel work items need to make use of the socket to perform transmission. These also need to get an active count on the local object to prevent the socket from being closed. Fix this by getting the active count in those places. Also split out the raw active count get/put functions as these places tend to hold refs on the rxrpc_local object already, so getting and putting an extra object ref is just a waste of time. The problem can lead to symptoms like: BUG: kernel NULL pointer dereference, address: 0000000000000018 .. CPU: 2 PID: 818 Comm: kworker/u9:0 Not tainted 5.5.0-fscache+ #51 ... RIP: 0010:selinux_socket_sendmsg+0x5/0x13 ... Call Trace: security_socket_sendmsg+0x2c/0x3e sock_sendmsg+0x1a/0x46 rxrpc_send_keepalive+0x131/0x1ae rxrpc_peer_keepalive_worker+0x219/0x34b process_one_work+0x18e/0x271 worker_thread+0x1a3/0x247 kthread+0xe6/0xeb ret_from_fork+0x1f/0x30 Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Signed-off-by: David Howells <dhowells@redhat.com>
2020-01-30rxrpc: Fix insufficient receive notification generationDavid Howells
In rxrpc_input_data(), rxrpc_notify_socket() is called if the base sequence number of the packet is immediately following the hard-ack point at the end of the function. However, this isn't sufficient, since the recvmsg side may have been advancing the window and then overrun the position in which we're adding - at which point rx_hard_ack >= seq0 and no notification is generated. Fix this by always generating a notification at the end of the input function. Without this, a long call may stall, possibly indefinitely. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>