kernel.git/net/core/sock.c, branch linux-6.8.y

net: mark racy access on sk->sk_rcvbuf

2024-05-17T10:14:38Z

[ Upstream commit c2deb2e971f5d9aca941ef13ee05566979e337a4 ] sk->sk_rcvbuf in __sock_queue_rcv_skb() and __sk_receive_skb() can be changed by other threads. Mark this as benign using READ_ONCE(). This patch is aimed at reducing the number of benign races reported by KCSAN in order to focus future debugging effort on harmful races. Signed-off-by: linke li Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: make SK_MEMORY_PCPU_RESERV tunable

2024-05-02T14:35:17Z

[ Upstream commit 12a686c2e761f1f1f6e6e2117a9ab9c6de2ac8a7 ] This patch adds /proc/sys/net/core/mem_pcpu_rsv sysctl file, to make SK_MEMORY_PCPU_RESERV tunable. Commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated") introduced per-cpu forward alloc cache: "Implement a per-cpu cache of +1/-1 MB, to reduce number of changes to sk->sk_prot->memory_allocated, which would otherwise be cause of false sharing." sk_prot->memory_allocated points to global atomic variable: atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp; If increasing the per-cpu cache size from 1MB to e.g. 16MB, changes to sk->sk_prot->memory_allocated can be further reduced. Performance may be improved on system with many cores. Signed-off-by: Adam Li Reviewed-by: Christoph Lameter (Ampere) Signed-off-by: David S. Miller Stable-dep-of: 3584718cf2ec ("net: fix sk_memory_allocated_{add|sub} vs softirqs") Signed-off-by: Sasha Levin

net: implement lockless setsockopt(SO_PEEK_OFF)

2024-02-21T11:24:20Z

syzbot reported a lockdep violation [1] involving af_unix support of SO_PEEK_OFF. Since SO_PEEK_OFF is inherently not thread safe (it uses a per-socket sk_peek_off field), there is really no point to enforce a pointless thread safety in the kernel. After this patch : - setsockopt(SO_PEEK_OFF) no longer acquires the socket lock. - skb_consume_udp() no longer has to acquire the socket lock. - af_unix no longer needs a special version of sk_set_peek_off(), because it does not lock u->iolock anymore. As a followup, we could replace prot->set_peek_off to be a boolean and avoid an indirect call, since we always use sk_set_peek_off(). [1] WARNING: possible circular locking dependency detected 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Not tainted syz-executor.2/30025 is trying to acquire lock: ffff8880765e7d80 (&u->iolock){+.+.}-{3:3}, at: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 but task is already holding lock: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline] ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_UNIX){+.+.}-{0:0}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 lock_sock_nested+0x48/0x100 net/core/sock.c:3524 lock_sock include/net/sock.h:1691 [inline] __unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046 ____sys_recvmsg+0x3c0/0x470 net/socket.c:2801 ___sys_recvmsg net/socket.c:2845 [inline] do_recvmmsg+0x474/0xae0 net/socket.c:2939 __sys_recvmmsg net/socket.c:3018 [inline] __do_sys_recvmmsg net/socket.c:3041 [inline] __se_sys_recvmmsg net/socket.c:3034 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #0 (&u->iolock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 sk_setsockopt+0x207e/0x3360 do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307 __sys_setsockopt+0x1ad/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_UNIX); lock(&u->iolock); lock(sk_lock-AF_UNIX); lock(&u->iolock); *** DEADLOCK *** 1 lock held by syz-executor.2/30025: #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline] #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline] #0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193 stack backtrace: CPU: 0 PID: 30025 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789 sk_setsockopt+0x207e/0x3360 do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307 __sys_setsockopt+0x1ad/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f78a1c7dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f78a0fde0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f78a1dac050 RCX: 00007f78a1c7dda9 RDX: 000000000000002a RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00007f78a1cca47a R08: 0000000000000004 R09: 0000000000000000 R10: 0000000020000180 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f78a1dac050 R15: 00007ffe5cd81ae8 Fixes: 859051dd165e ("bpf: Implement cgroup sockaddr hooks for unix sockets") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Cc: Daan De Meyer Cc: Kuniyuki Iwashima Cc: Martin KaFai Lau Cc: David Ahern Reviewed-by: Willem de Bruijn Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

udp: fix busy polling

2024-01-21T18:09:30Z

Generic sk_busy_loop_end() only looks at sk->sk_receive_queue for presence of packets. Problem is that for UDP sockets after blamed commit, some packets could be present in another queue: udp_sk(sk)->reader_queue In some cases, a busy poller could spin until timeout expiration, even if some packets are available in udp_sk(sk)->reader_queue. v3: - make sk_busy_loop_end() nicer (Willem) v2: - add a READ_ONCE(sk->sk_family) in sk_is_inet() to avoid KCSAN splats. - add a sk_is_inet() check in sk_is_udp() (Willem feedback) - add a sk_is_inet() check in sk_is_tcp(). Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception") Signed-off-by: Eric Dumazet Reviewed-by: Paolo Abeni Reviewed-by: Willem de Bruijn Reviewed-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-01-05T02:06:46Z

Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/broadcom/bnxt/bnxt.c e009b2efb7a8 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()") 0f2b21477988 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL") https://lore.kernel.org/all/20240105115509.225aa8a2@canb.auug.org.au/ Signed-off-by: Jakub Kicinski

net: Implement missing SO_TIMESTAMPING_NEW cmsg support

2024-01-04T16:18:55Z

Commit 9718475e6908 ("socket: Add SO_TIMESTAMPING_NEW") added the new socket option SO_TIMESTAMPING_NEW. However, it was never implemented in __sock_cmsg_send thus breaking SO_TIMESTAMPING cmsg for platforms using SO_TIMESTAMPING_NEW. Fixes: 9718475e6908 ("socket: Add SO_TIMESTAMPING_NEW") Link: https://lore.kernel.org/netdev/6a7281bf-bc4a-4f75-bb88-7011908ae471@app.fastmail.com/ Signed-off-by: Thomas Lange Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/20240104085744.49164-1-thomas@corelatus.se Signed-off-by: Jakub Kicinski

net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)

2024-01-02T13:24:30Z

Commit 9718475e6908 ("socket: Add SO_TIMESTAMPING_NEW") added the new socket option SO_TIMESTAMPING_NEW. Setting the option is handled in sk_setsockopt(), querying it was not handled in sk_getsockopt(), though. Following remarks on an earlier submission of this patch, keep the old behavior of getsockopt(SO_TIMESTAMPING_OLD) which returns the active flags even if they actually have been set through SO_TIMESTAMPING_NEW. The new getsockopt(SO_TIMESTAMPING_NEW) is stricter, returning flags only if they have been set through the same option. Fixes: 9718475e6908 ("socket: Add SO_TIMESTAMPING_NEW") Link: https://lore.kernel.org/lkml/20230703175048.151683-1-jthinz@mailbox.tu-berlin.de/ Link: https://lore.kernel.org/netdev/0d7cddc9-03fa-43db-a579-14f3e822615b@app.fastmail.com/ Signed-off-by: Jörn-Thorben Hinz Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller

net: Namespace-ify sysctl_optmem_max

2023-12-15T11:01:27Z

optmem_max being used in tx zerocopy, we want to be able to control it on a netns basis. Following patch changes two tests. Tested: oqq130:~# cat /proc/sys/net/core/optmem_max 131072 oqq130:~# echo 1000000 >/proc/sys/net/core/optmem_max oqq130:~# cat /proc/sys/net/core/optmem_max 1000000 oqq130:~# unshare -n oqq130:~# cat /proc/sys/net/core/optmem_max 131072 oqq130:~# exit logout oqq130:~# cat /proc/sys/net/core/optmem_max 1000000 Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Acked-by: Neal Cardwell Signed-off-by: David S. Miller

net: increase optmem_max default value

2023-12-15T11:01:26Z

For many years, /proc/sys/net/core/optmem_max default value on a 64bit kernel has been 20 KB. Regular usage of TCP tx zerocopy needs a bit more. Google has used 128KB as the default value for 7 years without any problem. Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Reviewed-by: Willem de Bruijn Acked-by: Neal Cardwell Signed-off-by: David S. Miller

Merge tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux

2023-11-01T21:16:34Z

Pull io_uring {get,set}sockopt support from Jens Axboe: "This adds support for using getsockopt and setsockopt via io_uring. The main use cases for this is to enable use of direct descriptors, rather than first instantiating a normal file descriptor, doing the option tweaking needed, then turning it into a direct descriptor. With this support, we can avoid needing a regular file descriptor completely. The net and bpf bits have been signed off on their side" * tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux: selftests/bpf/sockopt: Add io_uring support io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT io_uring/cmd: return -EOPNOTSUPP if net is disabled selftests/net: Extract uring helpers to be reusable tools headers: Grab copy of io_uring.h io_uring/cmd: Pass compat mode in issue_flags net/socket: Break down __sys_getsockopt net/socket: Break down __sys_setsockopt bpf: Add sockptr support for setsockopt bpf: Add sockptr support for getsockopt