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2024-05-02tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().Kuniyuki Iwashima
Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique() with nice analysis. Since commit ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's sk_refcnt after putting it into ehash and releasing the bucket lock. Thus, there is a small race window where other threads could try to reuse the port during connect() and call sock_hold() in tcp_twsk_unique() for the TIME-WAIT socket with zero refcnt. If that happens, the refcnt taken by tcp_twsk_unique() is overwritten and sock_put() will cause underflow, triggering a real use-after-free somewhere else. To avoid the use-after-free, we need to use refcount_inc_not_zero() in tcp_twsk_unique() and give up on reusing the port if it returns false. [0]: refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1 Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023 RIP: 0010:refcount_warn_saturate+0xe5/0x110 Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8 RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027 RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0 RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0 R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84 R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0 FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0 PKRU: 55555554 Call Trace: <TASK> ? refcount_warn_saturate+0xe5/0x110 ? __warn+0x81/0x130 ? refcount_warn_saturate+0xe5/0x110 ? report_bug+0x171/0x1a0 ? refcount_warn_saturate+0xe5/0x110 ? handle_bug+0x3c/0x80 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? refcount_warn_saturate+0xe5/0x110 tcp_twsk_unique+0x186/0x190 __inet_check_established+0x176/0x2d0 __inet_hash_connect+0x74/0x7d0 ? __pfx___inet_check_established+0x10/0x10 tcp_v4_connect+0x278/0x530 __inet_stream_connect+0x10f/0x3d0 inet_stream_connect+0x3a/0x60 __sys_connect+0xa8/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0x83/0x170 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7f62c11a885d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003 RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0 R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0 </TASK> Fixes: ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance") Reported-by: Anderson Nascimento <anderson@allelesecurity.com> Closes: https://lore.kernel.org/netdev/37a477a6-d39e-486b-9577-3463f655a6b7@allelesecurity.com/ Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240501213145.62261-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-28tcp: make dropreason in tcp_child_process() workJason Xing
It's time to let it work right now. We've already prepared for this:) Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-28tcp: make the dropreason really work when calling tcp_rcv_state_process()Jason Xing
Update three callers including both ipv4 and ipv6 and let the dropreason mechanism work in reality. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-28tcp: directly drop skb in cookie check for ipv4Jason Xing
Only move the skb drop from tcp_v4_do_rcv() to cookie_v4_check() itself, no other changes made. It can help us refine the specific drop reasons later. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-06net/tcp: Consistently align TCP-AO option in the headerDmitry Safonov
Currently functions that pre-calculate TCP header options length use unaligned TCP-AO header + MAC-length for skb reservation. And the functions that actually write TCP-AO options into skb do align the header. Nothing good can come out of this for ((maclen % 4) != 0). Provide tcp_ao_len_aligned() helper and use it everywhere for TCP header options space calculations. Fixes: 1e03d32bea8e ("net/tcp: Add TCP-AO sign to outgoing packets") Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-27net/tcp: Wire up l3index to TCP-AODmitry Safonov
Similarly how TCP_MD5SIG_FLAG_IFINDEX works for TCP-MD5, TCP_AO_KEYF_IFINDEX is an AO-key flag that binds that MKT to a specified by L3 ifinndex. Similarly, without this flag the key will work in the default VRF l3index = 0 for connections. To prevent AO-keys from overlapping, it's restricted to add key B for a socket that has key A, which have the same sndid/rcvid and one of the following is true: - !(A.keyflags & TCP_AO_KEYF_IFINDEX) or !(B.keyflags & TCP_AO_KEYF_IFINDEX) so that any key is non-bound to a VRF - A.l3index == B.l3index both want to work for the same VRF Additionally, it's restricted to match TCP-MD5 keys for the same peer the following way: |--------------|--------------------|----------------|---------------| | | MD5 key without | MD5 key | MD5 key | | | l3index | l3index=0 | l3index=N | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | without | reject | reject | reject | | l3index | | | | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | l3index=0 | reject | reject | allow | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | l3index=N | reject | allow | reject | |--------------|--------------------|----------------|---------------| This is done with the help of tcp_md5_do_lookup_any_l3index() to reject adding AO key without TCP_AO_KEYF_IFINDEX if there's TCP-MD5 in any VRF. This is important for case where sysctl_tcp_l3mdev_accept = 1 Similarly, for TCP-AO lookups tcp_ao_do_lookup() may be used with l3index < 0, so that __tcp_ao_key_cmp() will match TCP-AO key in any VRF. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add static_key for TCP-AODmitry Safonov
Similarly to TCP-MD5, add a static key to TCP-AO that is patched out when there are no keys on a machine and dynamically enabled with the first setsockopt(TCP_AO) adds a key on any socket. The static key is as well dynamically disabled later when the socket is destructed. The lifetime of enabled static key here is the same as ao_info: it is enabled on allocation, passed over from full socket to twsk and destructed when ao_info is scheduled for destruction. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Ignore specific ICMPs for TCP-AO connectionsDmitry Safonov
Similarly to IPsec, RFC5925 prescribes: ">> A TCP-AO implementation MUST default to ignore incoming ICMPv4 messages of Type 3 (destination unreachable), Codes 2-4 (protocol unreachable, port unreachable, and fragmentation needed -- ’hard errors’), and ICMPv6 Type 1 (destination unreachable), Code 1 (administratively prohibited) and Code 4 (port unreachable) intended for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN- WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs." A selftest (later in patch series) verifies that this attack is not possible in this TCP-AO implementation. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO SNE supportDmitry Safonov
Add Sequence Number Extension (SNE) for TCP-AO. This is needed to protect long-living TCP-AO connections from replaying attacks after sequence number roll-over, see RFC5925 (6.2). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO segments countersDmitry Safonov
Introduce segment counters that are useful for troubleshooting/debugging as well as for writing tests. Now there are global snmp counters as well as per-socket and per-key. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Verify inbound TCP-AO signed segmentsDmitry Safonov
Now there is a common function to verify signature on TCP segments: tcp_inbound_hash(). It has checks for all possible cross-interactions with MD5 signs as well as with unsigned segments. The rules from RFC5925 are: (1) Any TCP segment can have at max only one signature. (2) TCP connections can't switch between using TCP-MD5 and TCP-AO. (3) TCP-AO connections can't stop using AO, as well as unsigned connections can't suddenly start using AO. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Sign SYN-ACK segments with TCP-AODmitry Safonov
Similarly to RST segments, wire SYN-ACKs to TCP-AO. tcp_rsk_used_ao() is handy here to check if the request socket used AO and needs a signature on the outgoing segments. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Wire TCP-AO to request socketsDmitry Safonov
Now when the new request socket is created from the listening socket, it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is a new helper for checking if TCP-AO option was used to create the request socket. tcp_ao_copy_all_matching() will copy all keys that match the peer on the request socket, as well as preparing them for the usage (creating traffic keys). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO sign to twskDmitry Safonov
Add support for sockets in time-wait state. ao_info as well as all keys are inherited on transition to time-wait socket. The lifetime of ao_info is now protected by ref counter, so that tcp_ao_destroy_sock() will destruct it only when the last user is gone. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add AO sign to RST packetsDmitry Safonov
Wire up sending resets to TCP-AO hashing. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add tcp_parse_auth_options()Dmitry Safonov
Introduce a helper that: (1) shares the common code with TCP-MD5 header options parsing (2) looks for hash signature only once for both TCP-MD5 and TCP-AO (3) fails with -EEXIST if any TCP sign option is present twice, see RFC5925 (2.2): ">> A single TCP segment MUST NOT have more than one TCP-AO in its options sequence. When multiple TCP-AOs appear, TCP MUST discard the segment." Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO sign to outgoing packetsDmitry Safonov
Using precalculated traffic keys, sign TCP segments as prescribed by RFC5925. Per RFC, TCP header options are included in sign calculation: "The TCP header, by default including options, and where the TCP checksum and TCP-AO MAC fields are set to zero, all in network- byte order." (5.1.3) tcp_ao_hash_header() has exclude_options parameter to optionally exclude TCP header from hash calculation, as described in RFC5925 (9.1), this is needed for interaction with middleboxes that may change "some TCP options". This is wired up to AO key flags and setsockopt() later. Similarly to TCP-MD5 hash TCP segment fragments. From this moment a user can start sending TCP-AO signed segments with one of crypto ahash algorithms from supported by Linux kernel. It can have a user-specified MAC length, to either save TCP option header space or provide higher protection using a longer signature. The inbound segments are not yet verified, TCP-AO option is ignored and they are accepted. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Calculate TCP-AO traffic keysDmitry Safonov
Add traffic key calculation the way it's described in RFC5926. Wire it up to tcp_finish_connect() and cache the new keys straight away on already established TCP connections. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Prevent TCP-MD5 with TCP-AO being setDmitry Safonov
Be as conservative as possible: if there is TCP-MD5 key for a given peer regardless of L3 interface - don't allow setting TCP-AO key for the same peer. According to RFC5925, TCP-AO is supposed to replace TCP-MD5 and there can't be any switch between both on any connected tuple. Later it can be relaxed, if there's a use, but in the beginning restrict any intersection. Note: it's still should be possible to set both TCP-MD5 and TCP-AO keys on a listening socket for *different* peers. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Introduce TCP_AO setsockopt()sDmitry Safonov
Add 3 setsockopt()s: 1. TCP_AO_ADD_KEY to add a new Master Key Tuple (MKT) on a socket 2. TCP_AO_DEL_KEY to delete present MKT from a socket 3. TCP_AO_INFO to change flags, Current_key/RNext_key on a TCP-AO sk Userspace has to introduce keys on every socket it wants to use TCP-AO option on, similarly to TCP_MD5SIG/TCP_MD5SIG_EXT. RFC5925 prohibits definition of MKTs that would match the same peer, so do sanity checks on the data provided by userspace. Be as conservative as possible, including refusal of defining MKT on an established connection with no AO, removing the key in-use and etc. (1) and (2) are to be used by userspace key manager to add/remove keys. (3) main purpose is to set RNext_key, which (as prescribed by RFC5925) is the KeyID that will be requested in TCP-AO header from the peer to sign their segments with. At this moment the life of ao_info ends in tcp_v4_destroy_sock(). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Prepare tcp_md5sig_pool for TCP-AODmitry Safonov
TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path, which is setsockopt() and use crypto ahash requests on fast paths, which are RX/TX softirqs. Also, it needs a temporary/scratch buffer for preparing the hash. Rework tcp_md5sig_pool in order to support other hashing algorithms than MD5. It will make it possible to share pre-allocated crypto_ahash descriptors and scratch area between all TCP hash users. Internally tcp_sigpool calls crypto_clone_ahash() API over pre-allocated crypto ahash tfm. Kudos to Herbert, who provided this new crypto API. I was a little concerned over GFP_ATOMIC allocations of ahash and crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both "backends" with different algorithms, using patched version of iperf3[2]. On my laptop with i7-7600U @ 2.80GHz: clone-tfm per-CPU-requests TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec So, it seems that my concerns don't have strong grounds and per-CPU crypto_request allocation can be dropped/removed from tcp_sigpool once ciphers get crypto_clone_ahash() support. [1]: https://lore.kernel.org/all/ZDefxOq6Ax0JeTRH@gondor.apana.org.au/T/#u [2]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: add support for usec resolution in TCP TS valuesEric Dumazet
Back in 2015, Van Jacobson suggested to use usec resolution in TCP TS values. This has been implemented in our private kernels. Goals were : 1) better observability of delays in networking stacks. 2) better disambiguation of events based on TSval/ecr values. 3) building block for congestion control modules needing usec resolution. Back then we implemented a schem based on private SYN options to negotiate the feature. For upstream submission, we chose to use a route attribute, because this feature is probably going to be used in private networks [1] [2]. ip route add 10/8 ... features tcp_usec_ts Note that RFC 7323 recommends a "timestamp clock frequency in the range 1 ms to 1 sec per tick.", but also mentions "the maximum acceptable clock frequency is one tick every 59 ns." [1] Unfortunately RFC 7323 5.5 (Outdated Timestamps) suggests to invalidate TS.Recent values after a flow was idle for more than 24 days. This is the part making usec_ts a problem for peers following this recommendation for long living idle flows. [2] Attempts to standardize usec ts went nowhere: https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf https://datatracker.ietf.org/doc/draft-wang-tcpm-low-latency-opt/ Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: replace tcp_time_stamp_raw()Eric Dumazet
In preparation of usec TCP TS support, remove tcp_time_stamp_raw() in favor of tcp_clock_ts() helper. This helper will return a suitable 32bit result to feed TS values, depending on a socket field. Also add tcp_tw_tsval() and tcp_rsk_tsval() helpers to factorize the details. We do not yet support usec timestamps. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. net/mac80211/key.c 02e0e426a2fb ("wifi: mac80211: fix error path key leak") 2a8b665e6bcc ("wifi: mac80211: remove key_mtx") 7d6904bf26b9 ("Merge wireless into wireless-next") https://lore.kernel.org/all/20231012113648.46eea5ec@canb.auug.org.au/ Adjacent changes: drivers/net/ethernet/ti/Kconfig a602ee3176a8 ("net: ethernet: ti: Fix mixed module-builtin object") 98bdeae9502b ("net: cpmac: remove driver to prepare for platform removal") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-19tcp: check mptcp-level constraints for backlog coalescingPaolo Abeni
The MPTCP protocol can acquire the subflow-level socket lock and cause the tcp backlog usage. When inserting new skbs into the backlog, the stack will try to coalesce them. Currently, we have no check in place to ensure that such coalescing will respect the MPTCP-level DSS, and that may cause data stream corruption, as reported by Christoph. Address the issue by adding the relevant admission check for coalescing in tcp_add_backlog(). Note the issue is not easy to reproduce, as the MPTCP protocol tries hard to avoid acquiring the subflow-level socket lock. Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/420 Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231018-send-net-20231018-v1-2-17ecb002e41d@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-16Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-10-16 We've added 90 non-merge commits during the last 25 day(s) which contain a total of 120 files changed, 3519 insertions(+), 895 deletions(-). The main changes are: 1) Add missed stats for kprobes to retrieve the number of missed kprobe executions and subsequent executions of BPF programs, from Jiri Olsa. 2) Add cgroup BPF sockaddr hooks for unix sockets. The use case is for systemd to reimplement the LogNamespace feature which allows running multiple instances of systemd-journald to process the logs of different services, from Daan De Meyer. 3) Implement BPF CPUv4 support for s390x BPF JIT, from Ilya Leoshkevich. 4) Improve BPF verifier log output for scalar registers to better disambiguate their internal state wrt defaults vs min/max values matching, from Andrii Nakryiko. 5) Extend the BPF fib lookup helpers for IPv4/IPv6 to support retrieving the source IP address with a new BPF_FIB_LOOKUP_SRC flag, from Martynas Pumputis. 6) Add support for open-coded task_vma iterator to help with symbolization for BPF-collected user stacks, from Dave Marchevsky. 7) Add libbpf getters for accessing individual BPF ring buffers which is useful for polling them individually, for example, from Martin Kelly. 8) Extend AF_XDP selftests to validate the SHARED_UMEM feature, from Tushar Vyavahare. 9) Improve BPF selftests cross-building support for riscv arch, from Björn Töpel. 10) Add the ability to pin a BPF timer to the same calling CPU, from David Vernet. 11) Fix libbpf's bpf_tracing.h macros for riscv to use the generic implementation of PT_REGS_SYSCALL_REGS() to access syscall arguments, from Alexandre Ghiti. 12) Extend libbpf to support symbol versioning for uprobes, from Hengqi Chen. 13) Fix bpftool's skeleton code generation to guarantee that ELF data is 8 byte aligned, from Ian Rogers. 14) Inherit system-wide cpu_mitigations_off() setting for Spectre v1/v4 security mitigations in BPF verifier, from Yafang Shao. 15) Annotate struct bpf_stack_map with __counted_by attribute to prepare BPF side for upcoming __counted_by compiler support, from Kees Cook. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (90 commits) bpf: Ensure proper register state printing for cond jumps bpf: Disambiguate SCALAR register state output in verifier logs selftests/bpf: Make align selftests more robust selftests/bpf: Improve missed_kprobe_recursion test robustness selftests/bpf: Improve percpu_alloc test robustness selftests/bpf: Add tests for open-coded task_vma iter bpf: Introduce task_vma open-coded iterator kfuncs selftests/bpf: Rename bpf_iter_task_vma.c to bpf_iter_task_vmas.c bpf: Don't explicitly emit BTF for struct btf_iter_num bpf: Change syscall_nr type to int in struct syscall_tp_t net/bpf: Avoid unused "sin_addr_len" warning when CONFIG_CGROUP_BPF is not set bpf: Avoid unnecessary audit log for CPU security mitigations selftests/bpf: Add tests for cgroup unix socket address hooks selftests/bpf: Make sure mount directory exists documentation/bpf: Document cgroup unix socket address hooks bpftool: Add support for cgroup unix socket address hooks libbpf: Add support for cgroup unix socket address hooks bpf: Implement cgroup sockaddr hooks for unix sockets bpf: Add bpf_sock_addr_set_sun_path() to allow writing unix sockaddr from bpf bpf: Propagate modified uaddrlen from cgroup sockaddr programs ... ==================== Link: https://lore.kernel.org/r/20231016204803.30153-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-16tcp: Set pingpong threshold via sysctlHaiyang Zhang
TCP pingpong threshold is 1 by default. But some applications, like SQL DB may prefer a higher pingpong threshold to activate delayed acks in quick ack mode for better performance. The pingpong threshold and related code were changed to 3 in the year 2019 in: commit 4a41f453bedf ("tcp: change pingpong threshold to 3") And reverted to 1 in the year 2022 in: commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"") There is no single value that fits all applications. Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for optimal performance based on the application needs. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/1697056244-21888-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-11bpf: Propagate modified uaddrlen from cgroup sockaddr programsDaan De Meyer
As prep for adding unix socket support to the cgroup sockaddr hooks, let's propagate the sockaddr length back to the caller after running a bpf cgroup sockaddr hook program. While not important for AF_INET or AF_INET6, the sockaddr length is important when working with AF_UNIX sockaddrs as the size of the sockaddr cannot be determined just from the address family or the sockaddr's contents. __cgroup_bpf_run_filter_sock_addr() is modified to take the uaddrlen as an input/output argument. After running the program, the modified sockaddr length is stored in the uaddrlen pointer. Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com> Link: https://lore.kernel.org/r/20231011185113.140426-3-daan.j.demeyer@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-01inet: implement lockless IP_TOSEric Dumazet
Some reads of inet->tos are racy. Add needed READ_ONCE() annotations and convert IP_TOS option lockless. v2: missing changes in include/net/route.h (David Ahern) Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01net: implement lockless SO_PRIORITYEric Dumazet
This is a followup of 8bf43be799d4 ("net: annotate data-races around sk->sk_priority"). sk->sk_priority can be read and written without holding the socket lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-12tcp: defer regular ACK while processing socket backlogEric Dumazet
This idea came after a particular workload requested the quickack attribute set on routes, and a performance drop was noticed for large bulk transfers. For high throughput flows, it is best to use one cpu running the user thread issuing socket system calls, and a separate cpu to process incoming packets from BH context. (With TSO/GRO, bottleneck is usually the 'user' cpu) Problem is the user thread can spend a lot of time while holding the socket lock, forcing BH handler to queue most of incoming packets in the socket backlog. Whenever the user thread releases the socket lock, it must first process all accumulated packets in the backlog, potentially adding latency spikes. Due to flood mitigation, having too many packets in the backlog increases chance of unexpected drops. Backlog processing unfortunately shifts a fair amount of cpu cycles from the BH cpu to the 'user' cpu, thus reducing max throughput. This patch takes advantage of the backlog processing, and the fact that ACK are mostly cumulative. The idea is to detect we are in the backlog processing and defer all eligible ACK into a single one, sent from tcp_release_cb(). This saves cpu cycles on both sides, and network resources. Performance of a single TCP flow on a 200Gbit NIC: - Throughput is increased by 20% (100Gbit -> 120Gbit). - Number of generated ACK per second shrinks from 240,000 to 40,000. - Number of backlog drops per second shrinks from 230 to 0. Benchmark context: - Regular netperf TCP_STREAM (no zerocopy) - Intel(R) Xeon(R) Platinum 8481C (Saphire Rapids) - MAX_SKB_FRAGS = 17 (~60KB per GRO packet) This feature is guarded by a new sysctl, and enabled by default: /proc/sys/net/ipv4/tcp_backlog_ack_defer Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Dave Taht <dave.taht@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: include/net/inet_sock.h f866fbc842de ("ipv4: fix data-races around inet->inet_id") c274af224269 ("inet: introduce inet->inet_flags") https://lore.kernel.org/all/679ddff6-db6e-4ff6-b177-574e90d0103d@tessares.net/ Adjacent changes: drivers/net/bonding/bond_alb.c e74216b8def3 ("bonding: fix macvlan over alb bond support") f11e5bd159b0 ("bonding: support balance-alb with openvswitch") drivers/net/ethernet/broadcom/bgmac.c d6499f0b7c7c ("net: bgmac: Return PTR_ERR() for fixed_phy_register()") 23a14488ea58 ("net: bgmac: Fix return value check for fixed_phy_register()") drivers/net/ethernet/broadcom/genet/bcmmii.c 32bbe64a1386 ("net: bcmgenet: Fix return value check for fixed_phy_register()") acf50d1adbf4 ("net: bcmgenet: Return PTR_ERR() for fixed_phy_register()") net/sctp/socket.c f866fbc842de ("ipv4: fix data-races around inet->inet_id") b09bde5c3554 ("inet: move inet->mc_loop to inet->inet_frags") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-20ipv4: fix data-races around inet->inet_idEric Dumazet
UDP sendmsg() is lockless, so ip_select_ident_segs() can very well be run from multiple cpus [1] Convert inet->inet_id to an atomic_t, but implement a dedicated path for TCP, avoiding cost of a locked instruction (atomic_add_return()) Note that this patch will cause a trivial merge conflict because we added inet->flags in net-next tree. v2: added missing change in drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c (David Ahern) [1] BUG: KCSAN: data-race in __ip_make_skb / __ip_make_skb read-write to 0xffff888145af952a of 2 bytes by task 7803 on cpu 1: ip_select_ident_segs include/net/ip.h:542 [inline] ip_select_ident include/net/ip.h:556 [inline] __ip_make_skb+0x844/0xc70 net/ipv4/ip_output.c:1446 ip_make_skb+0x233/0x2c0 net/ipv4/ip_output.c:1560 udp_sendmsg+0x1199/0x1250 net/ipv4/udp.c:1260 inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg net/socket.c:748 [inline] ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2494 ___sys_sendmsg net/socket.c:2548 [inline] __sys_sendmmsg+0x269/0x500 net/socket.c:2634 __do_sys_sendmmsg net/socket.c:2663 [inline] __se_sys_sendmmsg net/socket.c:2660 [inline] __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2660 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888145af952a of 2 bytes by task 7804 on cpu 0: ip_select_ident_segs include/net/ip.h:541 [inline] ip_select_ident include/net/ip.h:556 [inline] __ip_make_skb+0x817/0xc70 net/ipv4/ip_output.c:1446 ip_make_skb+0x233/0x2c0 net/ipv4/ip_output.c:1560 udp_sendmsg+0x1199/0x1250 net/ipv4/udp.c:1260 inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg net/socket.c:748 [inline] ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2494 ___sys_sendmsg net/socket.c:2548 [inline] __sys_sendmmsg+0x269/0x500 net/socket.c:2634 __do_sys_sendmmsg net/socket.c:2663 [inline] __se_sys_sendmmsg net/socket.c:2660 [inline] __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2660 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x184d -> 0x184e Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 7804 Comm: syz-executor.1 Not tainted 6.5.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 ================================================================== Fixes: 23f57406b82d ("ipv4: avoid using shared IP generator for connected sockets") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16inet: move inet->recverr to inet->inet_flagsEric Dumazet
IP_RECVERR socket option can now be set/get without locking the socket. This patch potentially avoid data-races around inet->recverr. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/dsa/port.c 9945c1fb03a3 ("net: dsa: fix older DSA drivers using phylink") a88dd7538461 ("net: dsa: remove legacy_pre_march2020 detection") https://lore.kernel.org/all/20230731102254.2c9868ca@canb.auug.org.au/ net/xdp/xsk.c 3c5b4d69c358 ("net: annotate data-races around sk->sk_mark") b7f72a30e9ac ("xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path") https://lore.kernel.org/all/20230731102631.39988412@canb.auug.org.au/ drivers/net/ethernet/broadcom/bnxt/bnxt.c 37b61cda9c16 ("bnxt: don't handle XDP in netpoll") 2b56b3d99241 ("eth: bnxt: handle invalid Tx completions more gracefully") https://lore.kernel.org/all/20230801101708.1dc7faac@canb.auug.org.au/ Adjacent changes: drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c 62da08331f1a ("net/mlx5e: Set proper IPsec source port in L4 selector") fbd517549c32 ("net/mlx5e: Add function to get IPsec offload namespace") drivers/net/ethernet/sfc/selftest.c 55c1528f9b97 ("sfc: fix field-spanning memcpy in selftest") ae9d445cd41f ("sfc: Miscellaneous comment removals") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-29net: annotate data-races around sk->sk_priorityEric Dumazet
sk_getsockopt() runs locklessly. This means sk->sk_priority can be read while other threads are changing its value. Other reads also happen without socket lock being held. Add missing annotations where needed. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-29net: annotate data-races around sk->sk_markEric Dumazet
sk->sk_mark is often read while another thread could change the value. Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20tcp: annotate data-races around tp->tsoffsetEric Dumazet
do_tcp_getsockopt() reads tp->tsoffset while another cpu might change its value. Fixes: 93be6ce0e91b ("tcp: set and get per-socket timestamp") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-18tcp: annotate data-races around tcp_rsk(req)->ts_recentEric Dumazet
TCP request sockets are lockless, tcp_rsk(req)->ts_recent can change while being read by another cpu as syzbot noticed. This is harmless, but we should annotate the known races. Note that tcp_check_req() changes req->ts_recent a bit early, we might change this in the future. BUG: KCSAN: data-race in tcp_check_req / tcp_check_req write to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 1: tcp_check_req+0x694/0xc70 net/ipv4/tcp_minisocks.c:762 tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071 ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:303 [inline] ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:468 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5493 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607 process_backlog+0x21f/0x380 net/core/dev.c:5935 __napi_poll+0x60/0x3b0 net/core/dev.c:6498 napi_poll net/core/dev.c:6565 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6698 __do_softirq+0xc1/0x265 kernel/softirq.c:571 do_softirq+0x7e/0xb0 kernel/softirq.c:472 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:396 local_bh_enable+0x1f/0x20 include/linux/bottom_half.h:33 rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline] __dev_queue_xmit+0xabb/0x1d10 net/core/dev.c:4271 dev_queue_xmit include/linux/netdevice.h:3088 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0x700/0x840 net/ipv4/ip_output.c:229 ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:431 dst_output include/net/dst.h:458 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0xa4d/0xa70 net/ipv4/ip_output.c:533 ip_queue_xmit+0x38/0x40 net/ipv4/ip_output.c:547 __tcp_transmit_skb+0x1194/0x16e0 net/ipv4/tcp_output.c:1399 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline] tcp_write_xmit+0x13ff/0x2fd0 net/ipv4/tcp_output.c:2693 __tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:2877 tcp_push_pending_frames include/net/tcp.h:1952 [inline] __tcp_sock_set_cork net/ipv4/tcp.c:3336 [inline] tcp_sock_set_cork+0xe8/0x100 net/ipv4/tcp.c:3343 rds_tcp_xmit_path_complete+0x3b/0x40 net/rds/tcp_send.c:52 rds_send_xmit+0xf8d/0x1420 net/rds/send.c:422 rds_send_worker+0x42/0x1d0 net/rds/threads.c:200 process_one_work+0x3e6/0x750 kernel/workqueue.c:2408 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 read to 0xffff88813c8afb84 of 4 bytes by interrupt on cpu 0: tcp_check_req+0x32a/0xc70 net/ipv4/tcp_minisocks.c:622 tcp_v4_rcv+0x12db/0x1b70 net/ipv4/tcp_ipv4.c:2071 ip_protocol_deliver_rcu+0x356/0x6d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x13c/0x1a0 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:303 [inline] ip_local_deliver+0xec/0x1c0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:468 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip_rcv+0x197/0x270 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5493 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5607 process_backlog+0x21f/0x380 net/core/dev.c:5935 __napi_poll+0x60/0x3b0 net/core/dev.c:6498 napi_poll net/core/dev.c:6565 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6698 __do_softirq+0xc1/0x265 kernel/softirq.c:571 run_ksoftirqd+0x17/0x20 kernel/softirq.c:939 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 value changed: 0x1cd237f1 -> 0x1cd237f2 Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230717144445.653164-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-18tcp: annotate data-races around tcp_rsk(req)->txhashEric Dumazet
TCP request sockets are lockless, some of their fields can change while being read by another cpu as syzbot noticed. This is usually harmless, but we should annotate the known races. This patch takes care of tcp_rsk(req)->txhash, a separate one is needed for tcp_rsk(req)->ts_recent. BUG: KCSAN: data-race in tcp_make_synack / tcp_rtx_synack write to 0xffff8881362304bc of 4 bytes by task 32083 on cpu 1: tcp_rtx_synack+0x9d/0x2a0 net/ipv4/tcp_output.c:4213 inet_rtx_syn_ack+0x38/0x80 net/ipv4/inet_connection_sock.c:880 tcp_check_req+0x379/0xc70 net/ipv4/tcp_minisocks.c:665 tcp_v6_rcv+0x125b/0x1b20 net/ipv6/tcp_ipv6.c:1673 ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:437 ip6_input_finish net/ipv6/ip6_input.c:482 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:303 [inline] ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5452 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5566 netif_receive_skb_internal net/core/dev.c:5652 [inline] netif_receive_skb+0x4a/0x310 net/core/dev.c:5711 tun_rx_batched+0x3bf/0x400 tun_get_user+0x1d24/0x22b0 drivers/net/tun.c:1997 tun_chr_write_iter+0x18e/0x240 drivers/net/tun.c:2043 call_write_iter include/linux/fs.h:1871 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4ab/0x7d0 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff8881362304bc of 4 bytes by task 32078 on cpu 0: tcp_make_synack+0x367/0xb40 net/ipv4/tcp_output.c:3663 tcp_v6_send_synack+0x72/0x420 net/ipv6/tcp_ipv6.c:544 tcp_conn_request+0x11a8/0x1560 net/ipv4/tcp_input.c:7059 tcp_v6_conn_request+0x13f/0x180 net/ipv6/tcp_ipv6.c:1175 tcp_rcv_state_process+0x156/0x1de0 net/ipv4/tcp_input.c:6494 tcp_v6_do_rcv+0x98a/0xb70 net/ipv6/tcp_ipv6.c:1509 tcp_v6_rcv+0x17b8/0x1b20 net/ipv6/tcp_ipv6.c:1735 ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:437 ip6_input_finish net/ipv6/ip6_input.c:482 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:468 [inline] ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:303 [inline] ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5452 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5566 netif_receive_skb_internal net/core/dev.c:5652 [inline] netif_receive_skb+0x4a/0x310 net/core/dev.c:5711 tun_rx_batched+0x3bf/0x400 tun_get_user+0x1d24/0x22b0 drivers/net/tun.c:1997 tun_chr_write_iter+0x18e/0x240 drivers/net/tun.c:2043 call_write_iter include/linux/fs.h:1871 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4ab/0x7d0 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x91d25731 -> 0xe79325cd Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 32078 Comm: syz-executor.4 Not tainted 6.5.0-rc1-syzkaller-00033-geb26cbb1a754 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230717144445.653164-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-12tcp: add a scheduling point in established_get_first()Jian Wen
Kubernetes[1] is going to stick with /proc/net/tcp for a while. This commit reduces the scheduling latency introduced by established_get_first(), similar to commit acffb584cda7 ("net: diag: add a scheduling point in inet_diag_dump_icsk()"). In our environment, the scheduling latency affects the performance of latency-sensitive services like Redis. Changes in V2 : - call cond_resched() before checking if a bucket is empty as suggested by Eric Dumazet - removed the delay of synchronize_net() from the commit message [1] https://github.com/google/cadvisor/blob/v0.47.2/container/libcontainer/handler.go#L130 Signed-off-by: Jian Wen <wenjian1@xiaomi.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230711032405.3253025-1-wenjian1@xiaomi.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)David Howells
Remove ->sendpage() and ->sendpage_locked(). sendmsg() with MSG_SPLICE_PAGES should be used instead. This allows multiple pages and multipage folios to be passed through. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: linux-afs@lists.infradead.org cc: mptcp@lists.linux.dev cc: rds-devel@oss.oracle.com cc: tipc-discussion@lists.sourceforge.net cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-17tcp: enforce receive buffer memory limits by allowing the tcp window to shrinkmfreemon@cloudflare.com
Under certain circumstances, the tcp receive buffer memory limit set by autotuning (sk_rcvbuf) is increased due to incoming data packets as a result of the window not closing when it should be. This can result in the receive buffer growing all the way up to tcp_rmem[2], even for tcp sessions with a low BDP. To reproduce: Connect a TCP session with the receiver doing nothing and the sender sending small packets (an infinite loop of socket send() with 4 bytes of payload with a sleep of 1 ms in between each send()). This will cause the tcp receive buffer to grow all the way up to tcp_rmem[2]. As a result, a host can have individual tcp sessions with receive buffers of size tcp_rmem[2], and the host itself can reach tcp_mem limits, causing the host to go into tcp memory pressure mode. The fundamental issue is the relationship between the granularity of the window scaling factor and the number of byte ACKed back to the sender. This problem has previously been identified in RFC 7323, appendix F [1]. The Linux kernel currently adheres to never shrinking the window. In addition to the overallocation of memory mentioned above, the current behavior is functionally incorrect, because once tcp_rmem[2] is reached when no remediations remain (i.e. tcp collapse fails to free up any more memory and there are no packets to prune from the out-of-order queue), the receiver will drop in-window packets resulting in retransmissions and an eventual timeout of the tcp session. A receive buffer full condition should instead result in a zero window and an indefinite wait. In practice, this problem is largely hidden for most flows. It is not applicable to mice flows. Elephant flows can send data fast enough to "overrun" the sk_rcvbuf limit (in a single ACK), triggering a zero window. But this problem does show up for other types of flows. Examples are websockets and other type of flows that send small amounts of data spaced apart slightly in time. In these cases, we directly encounter the problem described in [1]. RFC 7323, section 2.4 [2], says there are instances when a retracted window can be offered, and that TCP implementations MUST ensure that they handle a shrinking window, as specified in RFC 1122, section 4.2.2.16 [3]. All prior RFCs on the topic of tcp window management have made clear that sender must accept a shrunk window from the receiver, including RFC 793 [4] and RFC 1323 [5]. This patch implements the functionality to shrink the tcp window when necessary to keep the right edge within the memory limit by autotuning (sk_rcvbuf). This new functionality is enabled with the new sysctl: net.ipv4.tcp_shrink_window Additional information can be found at: https://blog.cloudflare.com/unbounded-memory-usage-by-tcp-for-receive-buffers-and-how-we-fixed-it/ [1] https://www.rfc-editor.org/rfc/rfc7323#appendix-F [2] https://www.rfc-editor.org/rfc/rfc7323#section-2.4 [3] https://www.rfc-editor.org/rfc/rfc1122#page-91 [4] https://www.rfc-editor.org/rfc/rfc793 [5] https://www.rfc-editor.org/rfc/rfc1323 Signed-off-by: Mike Freemon <mfreemon@cloudflare.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-08ipv4, ipv6: Use splice_eof() to flushDavid Howells
Allow splice to undo the effects of MSG_MORE after prematurely ending a splice/sendfile due to getting an EOF condition (->splice_read() returned 0) after splice had called sendmsg() with MSG_MORE set when the user didn't set MSG_MORE. For UDP, a pending packet will not be emitted if the socket is closed before it is flushed; with this change, it be flushed by ->splice_eof(). For TCP, it's not clear that MSG_MORE is actually effective. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/ Signed-off-by: David Howells <dhowells@redhat.com> cc: Kuniyuki Iwashima <kuniyu@amazon.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-26Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-26 We've added 54 non-merge commits during the last 10 day(s) which contain a total of 76 files changed, 2729 insertions(+), 1003 deletions(-). The main changes are: 1) Add the capability to destroy sockets in BPF through a new kfunc, from Aditi Ghag. 2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands, from Andrii Nakryiko. 3) Add capability for libbpf to resize datasec maps when backed via mmap, from JP Kobryn. 4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod, from Jiri Olsa. 5) Big batch of xsk selftest improvements to prep for multi-buffer testing, from Magnus Karlsson. 6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it via bpftool, from Yafang Shao. 7) Various misc BPF selftest improvements to work with upcoming LLVM 17, from Yonghong Song. 8) Extend bpftool to specify netdevice for resolving XDP hints, from Larysa Zaremba. 9) Document masking in shift operations for the insn set document, from Dave Thaler. 10) Extend BPF selftests to check xdp_feature support for bond driver, from Lorenzo Bianconi. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits) bpf: Fix bad unlock balance on freeze_mutex libbpf: Ensure FD >= 3 during bpf_map__reuse_fd() libbpf: Ensure libbpf always opens files with O_CLOEXEC selftests/bpf: Check whether to run selftest libbpf: Change var type in datasec resize func bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command libbpf: Selftests for resizing datasec maps libbpf: Add capability for resizing datasec maps selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands libbpf: Start v1.3 development cycle bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM bpftool: Specify XDP Hints ifname when loading program selftests/bpf: Add xdp_feature selftest for bond device selftests/bpf: Test bpf_sock_destroy selftests/bpf: Add helper to get port using getsockname bpf: Add bpf_sock_destroy kfunc bpf: Add kfunc filter function to 'struct btf_kfunc_id_set' bpf: udp: Implement batching for sockets iterator ... ==================== Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25net: ipv4: use consistent txhash in TIME_WAIT and SYN_RECVAntoine Tenart
When using IPv4/TCP, skb->hash comes from sk->sk_txhash except in TIME_WAIT and SYN_RECV where it's not set in the reply skb from ip_send_unicast_reply. Those packets will have a mismatched hash with others from the same flow as their hashes will be 0. IPv6 does not have the same issue as the hash is set from the socket txhash in those cases. This commits sets the hash in the reply skb from ip_send_unicast_reply, which makes the IPv4 code behaving like IPv6. Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-19bpf: Add bpf_sock_destroy kfuncAditi Ghag
The socket destroy kfunc is used to forcefully terminate sockets from certain BPF contexts. We plan to use the capability in Cilium load-balancing to terminate client sockets that continue to connect to deleted backends. The other use case is on-the-fly policy enforcement where existing socket connections prevented by policies need to be forcefully terminated. The kfunc also allows terminating sockets that may or may not be actively sending traffic. The kfunc can currently be called only from BPF TCP and UDP iterators where users can filter, and terminate selected sockets. More specifically, it can only be called from BPF contexts that ensure socket locking in order to allow synchronous execution of protocol specific `diag_destroy` handlers. The previous commit that batches UDP sockets during iteration facilitated a synchronous invocation of the UDP destroy callback from BPF context by skipping socket locks in `udp_abort`. TCP iterator already supported batching of sockets being iterated. To that end, `tracing_iter_filter` callback filter is added so that verifier can restrict the kfunc to programs with `BPF_TRACE_ITER` attach type, and reject other programs. The kfunc takes `sock_common` type argument, even though it expects, and casts them to a `sock` pointer. This enables the verifier to allow the sock_destroy kfunc to be called for TCP with `sock_common` and UDP with `sock` structs. Furthermore, as `sock_common` only has a subset of certain fields of `sock`, casting pointer to the latter type might not always be safe for certain sockets like request sockets, but these have a special handling in the diag_destroy handlers. Additionally, the kfunc is defined with `KF_TRUSTED_ARGS` flag to avoid the cases where a `PTR_TO_BTF_ID` sk is obtained by following another pointer. eg. getting a sk pointer (may be even NULL) by following another sk pointer. The pointer socket argument passed in TCP and UDP iterators is tagged as `PTR_TRUSTED` in {tcp,udp}_reg_info. The TRUSTED arg changes are contributed by Martin KaFai Lau <martin.lau@kernel.org>. Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com> Link: https://lore.kernel.org/r/20230519225157.760788-8-aditi.ghag@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-19bpf: tcp: Avoid taking fast sock lock in iteratorAditi Ghag
This is a preparatory commit to replace `lock_sock_fast` with `lock_sock`,and facilitate BPF programs executed from the TCP sockets iterator to be able to destroy TCP sockets using the bpf_sock_destroy kfunc (implemented in follow-up commits). Previously, BPF TCP iterator was acquiring the sock lock with BH disabled. This led to scenarios where the sockets hash table bucket lock can be acquired with BH enabled in some path versus disabled in other. In such situation, kernel issued a warning since it thinks that in the BH enabled path the same bucket lock *might* be acquired again in the softirq context (BH disabled), which will lead to a potential dead lock. Since bpf_sock_destroy also happens in a process context, the potential deadlock warning is likely a false alarm. Here is a snippet of annotated stack trace that motivated this change: ``` Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&h->lhash2[i].lock); local_bh_disable(); lock(&h->lhash2[i].lock); kernel imagined possible scenario: local_bh_disable(); /* Possible softirq */ lock(&h->lhash2[i].lock); *** Potential Deadlock *** process context: lock_acquire+0xcd/0x330 _raw_spin_lock+0x33/0x40 ------> Acquire (bucket) lhash2.lock with BH enabled __inet_hash+0x4b/0x210 inet_csk_listen_start+0xe6/0x100 inet_listen+0x95/0x1d0 __sys_listen+0x69/0xb0 __x64_sys_listen+0x14/0x20 do_syscall_64+0x3c/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc bpf_sock_destroy run from iterator: lock_acquire+0xcd/0x330 _raw_spin_lock+0x33/0x40 ------> Acquire (bucket) lhash2.lock with BH disabled inet_unhash+0x9a/0x110 tcp_set_state+0x6a/0x210 tcp_abort+0x10d/0x200 bpf_prog_6793c5ca50c43c0d_iter_tcp6_server+0xa4/0xa9 bpf_iter_run_prog+0x1ff/0x340 ------> lock_sock_fast that acquires sock lock with BH disabled bpf_iter_tcp_seq_show+0xca/0x190 bpf_seq_read+0x177/0x450 ``` Also, Yonghong reported a deadlock for non-listening TCP sockets that this change resolves. Previously, `lock_sock_fast` held the sock spin lock with BH which was again being acquired in `tcp_abort`: ``` watchdog: BUG: soft lockup - CPU#0 stuck for 86s! [test_progs:2331] RIP: 0010:queued_spin_lock_slowpath+0xd8/0x500 Call Trace: <TASK> _raw_spin_lock+0x84/0x90 tcp_abort+0x13c/0x1f0 bpf_prog_88539c5453a9dd47_iter_tcp6_client+0x82/0x89 bpf_iter_run_prog+0x1aa/0x2c0 ? preempt_count_sub+0x1c/0xd0 ? from_kuid_munged+0x1c8/0x210 bpf_iter_tcp_seq_show+0x14e/0x1b0 bpf_seq_read+0x36c/0x6a0 bpf_iter_tcp_seq_show lock_sock_fast __lock_sock_fast spin_lock_bh(&sk->sk_lock.slock); /* * Fast path return with bottom halves disabled and * sock::sk_lock.slock held.* */ ... tcp_abort local_bh_disable(); spin_lock(&((sk)->sk_lock.slock)); // from bh_lock_sock(sk) ``` With the switch to `lock_sock`, it calls `spin_unlock_bh` before returning: ``` lock_sock lock_sock_nested spin_lock_bh(&sk->sk_lock.slock); : spin_unlock_bh(&sk->sk_lock.slock); ``` Acked-by: Yonghong Song <yhs@meta.com> Acked-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com> Link: https://lore.kernel.org/r/20230519225157.760788-2-aditi.ghag@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: drivers/net/ethernet/freescale/fec_main.c 6ead9c98cafc ("net: fec: remove the xdp_return_frame when lack of tx BDs") 144470c88c5d ("net: fec: using the standard return codes when xdp xmit errors") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
generated by cgit (git 2.34.1) at 2024-06-12 04:02:55 +0000