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2023-09-19af_unix: Fix data-race around unix_tot_inflight.Kuniyuki Iwashima1-1/+1
[ Upstream commit ade32bd8a738d7497ffe9743c46728db26740f78 ] unix_tot_inflight is changed under spin_lock(unix_gc_lock), but unix_release_sock() reads it locklessly. Let's use READ_ONCE() for unix_tot_inflight. Note that the writer side was marked by commit 9d6d7f1cb67c ("af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress") BUG: KCSAN: data-race in unix_inflight / unix_release_sock write (marked) to 0xffffffff871852b8 of 4 bytes by task 123 on cpu 1: unix_inflight+0x130/0x180 net/unix/scm.c:64 unix_attach_fds+0x137/0x1b0 net/unix/scm.c:123 unix_scm_to_skb net/unix/af_unix.c:1832 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1955 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x148/0x160 net/socket.c:747 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2493 ___sys_sendmsg+0xc6/0x140 net/socket.c:2547 __sys_sendmsg+0x94/0x140 net/socket.c:2576 __do_sys_sendmsg net/socket.c:2585 [inline] __se_sys_sendmsg net/socket.c:2583 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2583 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffffffff871852b8 of 4 bytes by task 4891 on cpu 0: unix_release_sock+0x608/0x910 net/unix/af_unix.c:671 unix_release+0x59/0x80 net/unix/af_unix.c:1058 __sock_release+0x7d/0x170 net/socket.c:653 sock_close+0x19/0x30 net/socket.c:1385 __fput+0x179/0x5e0 fs/file_table.c:321 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x116/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x00000000 -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 4891 Comm: systemd-coredum Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 9305cfa4443d ("[AF_UNIX]: Make unix_tot_inflight counter non-atomic") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19af_unix: Fix data-races around user->unix_inflight.Kuniyuki Iwashima1-3/+3
[ Upstream commit 0bc36c0650b21df36fbec8136add83936eaf0607 ] user->unix_inflight is changed under spin_lock(unix_gc_lock), but too_many_unix_fds() reads it locklessly. Let's annotate the write/read accesses to user->unix_inflight. BUG: KCSAN: data-race in unix_attach_fds / unix_inflight write to 0xffffffff8546f2d0 of 8 bytes by task 44798 on cpu 1: unix_inflight+0x157/0x180 net/unix/scm.c:66 unix_attach_fds+0x147/0x1e0 net/unix/scm.c:123 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 read to 0xffffffff8546f2d0 of 8 bytes by task 44814 on cpu 0: too_many_unix_fds net/unix/scm.c:101 [inline] unix_attach_fds+0x54/0x1e0 net/unix/scm.c:110 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 value changed: 0x000000000000000c -> 0x000000000000000d Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 44814 Comm: systemd-coredum Not tainted 6.4.0-11989-g6843306689af #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 712f4aad406b ("unix: properly account for FDs passed over unix sockets") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Willy Tarreau <w@1wt.eu> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-26af_unix: Fix null-ptr-deref in unix_stream_sendpage().Kuniyuki Iwashima1-5/+4
Bing-Jhong Billy Jheng reported null-ptr-deref in unix_stream_sendpage() with detailed analysis and a nice repro. unix_stream_sendpage() tries to add data to the last skb in the peer's recv queue without locking the queue. If the peer's FD is passed to another socket and the socket's FD is passed to the peer, there is a loop between them. If we close both sockets without receiving FD, the sockets will be cleaned up by garbage collection. The garbage collection iterates such sockets and unlinks skb with FD from the socket's receive queue under the queue's lock. So, there is a race where unix_stream_sendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free. To avoid the issue, unix_stream_sendpage() must lock the peer's recv queue. Note the issue does not exist in 6.5+ thanks to the recent sendpage() refactoring. This patch is originally written by Linus Torvalds. BUG: unable to handle page fault for address: ffff988004dd6870 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 P4D 0 PREEMPT SMP PTI CPU: 4 PID: 297 Comm: garbage_uaf Not tainted 6.1.46 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:kmem_cache_alloc_node+0xa2/0x1e0 Code: c0 0f 84 32 01 00 00 41 83 fd ff 74 10 48 8b 00 48 c1 e8 3a 41 39 c5 0f 85 1c 01 00 00 41 8b 44 24 28 49 8b 3c 24 48 8d 4a 40 <49> 8b 1c 06 4c 89 f0 65 48 0f c7 0f 0f 94 c0 84 c0 74 a1 41 8b 44 RSP: 0018:ffffc9000079fac0 EFLAGS: 00000246 RAX: 0000000000000070 RBX: 0000000000000005 RCX: 000000000001a284 RDX: 000000000001a244 RSI: 0000000000400cc0 RDI: 000000000002eee0 RBP: 0000000000400cc0 R08: 0000000000400cc0 R09: 0000000000000003 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888003970f00 R13: 00000000ffffffff R14: ffff988004dd6800 R15: 00000000000000e8 FS: 00007f174d6f3600(0000) GS:ffff88807db00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff988004dd6870 CR3: 00000000092be000 CR4: 00000000007506e0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x1a/0x1f ? page_fault_oops+0xa9/0x1e0 ? fixup_exception+0x1d/0x310 ? exc_page_fault+0xa8/0x150 ? asm_exc_page_fault+0x22/0x30 ? kmem_cache_alloc_node+0xa2/0x1e0 ? __alloc_skb+0x16c/0x1e0 __alloc_skb+0x16c/0x1e0 alloc_skb_with_frags+0x48/0x1e0 sock_alloc_send_pskb+0x234/0x270 unix_stream_sendmsg+0x1f5/0x690 sock_sendmsg+0x5d/0x60 ____sys_sendmsg+0x210/0x260 ___sys_sendmsg+0x83/0xd0 ? kmem_cache_alloc+0xc6/0x1c0 ? avc_disable+0x20/0x20 ? percpu_counter_add_batch+0x53/0xc0 ? alloc_empty_file+0x5d/0xb0 ? alloc_file+0x91/0x170 ? alloc_file_pseudo+0x94/0x100 ? __fget_light+0x9f/0x120 __sys_sendmsg+0x54/0xa0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x69/0xd3 RIP: 0033:0x7f174d639a7d Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 8a c1 f4 ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 44 24 08 e8 de c1 f4 ff 48 RSP: 002b:00007ffcb563ea50 EFLAGS: 00000293 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f174d639a7d RDX: 0000000000000000 RSI: 00007ffcb563eab0 RDI: 0000000000000007 RBP: 00007ffcb563eb10 R08: 0000000000000000 R09: 00000000ffffffff R10: 00000000004040a0 R11: 0000000000000293 R12: 00007ffcb563ec28 R13: 0000000000401398 R14: 0000000000403e00 R15: 00007f174d72c000 </TASK> Fixes: 869e7c62486e ("net: af_unix: implement stream sendpage support") Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Reviewed-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-11net: add missing data-race annotations around sk->sk_peek_offEric Dumazet1-1/+1
[ Upstream commit 11695c6e966b0ec7ed1d16777d294cef865a5c91 ] sk_getsockopt() runs locklessly, thus we need to annotate the read of sk->sk_peek_off. While we are at it, add corresponding annotations to sk_set_peek_off() and unix_set_peek_off(). Fixes: b9bb53f3836f ("sock: convert sk_peek_offset functions to WRITE_ONCE") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30af_unix: Fix data races around sk->sk_shutdown.Kuniyuki Iwashima1-8/+12
[ Upstream commit e1d09c2c2f5793474556b60f83900e088d0d366d ] KCSAN found a data race around sk->sk_shutdown where unix_release_sock() and unix_shutdown() update it under unix_state_lock(), OTOH unix_poll() and unix_dgram_poll() read it locklessly. We need to annotate the writes and reads with WRITE_ONCE() and READ_ONCE(). BUG: KCSAN: data-race in unix_poll / unix_release_sock write to 0xffff88800d0f8aec of 1 bytes by task 264 on cpu 0: unix_release_sock+0x75c/0x910 net/unix/af_unix.c:631 unix_release+0x59/0x80 net/unix/af_unix.c:1042 __sock_release+0x7d/0x170 net/socket.c:653 sock_close+0x19/0x30 net/socket.c:1397 __fput+0x179/0x5e0 fs/file_table.c:321 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x116/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88800d0f8aec of 1 bytes by task 222 on cpu 1: unix_poll+0xa3/0x2a0 net/unix/af_unix.c:3170 sock_poll+0xcf/0x2b0 net/socket.c:1385 vfs_poll include/linux/poll.h:88 [inline] ep_item_poll.isra.0+0x78/0xc0 fs/eventpoll.c:855 ep_send_events fs/eventpoll.c:1694 [inline] ep_poll fs/eventpoll.c:1823 [inline] do_epoll_wait+0x6c4/0xea0 fs/eventpoll.c:2258 __do_sys_epoll_wait fs/eventpoll.c:2270 [inline] __se_sys_epoll_wait fs/eventpoll.c:2265 [inline] __x64_sys_epoll_wait+0xcc/0x190 fs/eventpoll.c:2265 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x00 -> 0x03 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 222 Comm: dbus-broker Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 3c73419c09a5 ("af_unix: fix 'poll for write'/ connected DGRAM sockets") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30af_unix: Fix a data race of sk->sk_receive_queue->qlen.Kuniyuki Iwashima1-1/+1
[ Upstream commit 679ed006d416ea0cecfe24a99d365d1dea69c683 ] KCSAN found a data race of sk->sk_receive_queue->qlen where recvmsg() updates qlen under the queue lock and sendmsg() checks qlen under unix_state_sock(), not the queue lock, so the reader side needs READ_ONCE(). BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_wait_for_peer write (marked) to 0xffff888019fe7c68 of 4 bytes by task 49792 on cpu 0: __skb_unlink include/linux/skbuff.h:2347 [inline] __skb_try_recv_from_queue+0x3de/0x470 net/core/datagram.c:197 __skb_try_recv_datagram+0xf7/0x390 net/core/datagram.c:263 __unix_dgram_recvmsg+0x109/0x8a0 net/unix/af_unix.c:2452 unix_dgram_recvmsg+0x94/0xa0 net/unix/af_unix.c:2549 sock_recvmsg_nosec net/socket.c:1019 [inline] ____sys_recvmsg+0x3a3/0x3b0 net/socket.c:2720 ___sys_recvmsg+0xc8/0x150 net/socket.c:2764 do_recvmmsg+0x182/0x560 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x153/0x170 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff888019fe7c68 of 4 bytes by task 49793 on cpu 1: skb_queue_len include/linux/skbuff.h:2127 [inline] unix_recvq_full net/unix/af_unix.c:229 [inline] unix_wait_for_peer+0x154/0x1a0 net/unix/af_unix.c:1445 unix_dgram_sendmsg+0x13bc/0x14b0 net/unix/af_unix.c:2048 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x148/0x160 net/socket.c:747 ____sys_sendmsg+0x20e/0x620 net/socket.c:2503 ___sys_sendmsg+0xc6/0x140 net/socket.c:2557 __sys_sendmmsg+0x11d/0x370 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x58/0x70 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x0000000b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 49793 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14af_unix: Get user_ns from in_skb in unix_diag_get_exact().Kuniyuki Iwashima1-8/+12
[ Upstream commit b3abe42e94900bdd045c472f9c9be620ba5ce553 ] Wei Chen reported a NULL deref in sk_user_ns() [0][1], and Paolo diagnosed the root cause: in unix_diag_get_exact(), the newly allocated skb does not have sk. [2] We must get the user_ns from the NETLINK_CB(in_skb).sk and pass it to sk_diag_fill(). [0]: BUG: kernel NULL pointer dereference, address: 0000000000000270 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 12bbce067 P4D 12bbce067 PUD 12bc40067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 27942 Comm: syz-executor.0 Not tainted 6.1.0-rc5-next-20221118 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014 RIP: 0010:sk_user_ns include/net/sock.h:920 [inline] RIP: 0010:sk_diag_dump_uid net/unix/diag.c:119 [inline] RIP: 0010:sk_diag_fill+0x77d/0x890 net/unix/diag.c:170 Code: 89 ef e8 66 d4 2d fd c7 44 24 40 00 00 00 00 49 8d 7c 24 18 e8 54 d7 2d fd 49 8b 5c 24 18 48 8d bb 70 02 00 00 e8 43 d7 2d fd <48> 8b 9b 70 02 00 00 48 8d 7b 10 e8 33 d7 2d fd 48 8b 5b 10 48 8d RSP: 0018:ffffc90000d67968 EFLAGS: 00010246 RAX: ffff88812badaa48 RBX: 0000000000000000 RCX: ffffffff840d481d RDX: 0000000000000465 RSI: 0000000000000000 RDI: 0000000000000270 RBP: ffffc90000d679a8 R08: 0000000000000277 R09: 0000000000000000 R10: 0001ffffffffffff R11: 0001c90000d679a8 R12: ffff88812ac03800 R13: ffff88812c87c400 R14: ffff88812ae42210 R15: ffff888103026940 FS: 00007f08b4e6f700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000270 CR3: 000000012c58b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> unix_diag_get_exact net/unix/diag.c:285 [inline] unix_diag_handler_dump+0x3f9/0x500 net/unix/diag.c:317 __sock_diag_cmd net/core/sock_diag.c:235 [inline] sock_diag_rcv_msg+0x237/0x250 net/core/sock_diag.c:266 netlink_rcv_skb+0x13e/0x250 net/netlink/af_netlink.c:2564 sock_diag_rcv+0x24/0x40 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x5e9/0x6b0 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x739/0x860 net/netlink/af_netlink.c:1932 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x38f/0x500 net/socket.c:2476 ___sys_sendmsg net/socket.c:2530 [inline] __sys_sendmsg+0x197/0x230 net/socket.c:2559 __do_sys_sendmsg net/socket.c:2568 [inline] __se_sys_sendmsg net/socket.c:2566 [inline] __x64_sys_sendmsg+0x42/0x50 net/socket.c:2566 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x4697f9 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f08b4e6ec48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000077bf80 RCX: 00000000004697f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00000000004d29e9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000077bf80 R13: 0000000000000000 R14: 000000000077bf80 R15: 00007ffdb36bc6c0 </TASK> Modules linked in: CR2: 0000000000000270 [1]: https://lore.kernel.org/netdev/CAO4mrfdvyjFpokhNsiwZiP-wpdSD0AStcJwfKcKQdAALQ9_2Qw@mail.gmail.com/ [2]: https://lore.kernel.org/netdev/e04315e7c90d9a75613f3993c2baf2d344eef7eb.camel@redhat.com/ Fixes: cae9910e7344 ("net: Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics.") Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: Wei Chen <harperchen1110@gmail.com> Diagnosed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26io_uring/af_unix: defer registered files gc to io_uring releasePavel Begunkov1-0/+20
[ upstream commit 0091bfc81741b8d3aeb3b7ab8636f911b2de6e80 ] Instead of putting io_uring's registered files in unix_gc() we want it to be done by io_uring itself. The trick here is to consider io_uring registered files for cycle detection but not actually putting them down. Because io_uring can't register other ring instances, this will remove all refs to the ring file triggering the ->release path and clean up with io_ring_ctx_free(). Cc: stable@vger.kernel.org Fixes: 6b06314c47e1 ("io_uring: add file set registration") Reported-and-tested-by: David Bouman <dbouman03@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> [axboe: add kerneldoc comment to skb, fold in skb leak fix] Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14af_unix: Fix a data-race in unix_dgram_peer_wake_me().Kuniyuki Iwashima1-1/+1
[ Upstream commit 662a80946ce13633ae90a55379f1346c10f0c432 ] unix_dgram_poll() calls unix_dgram_peer_wake_me() without `other`'s lock held and check if its receive queue is full. Here we need to use unix_recvq_full_lockless() instead of unix_recvq_full(), otherwise KCSAN will report a data-race. Fixes: 7d267278a9ec ("unix: avoid use-after-free in ep_remove_wait_queue") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20220605232325.11804-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progressEric Dumazet2-5/+15
commit 9d6d7f1cb67cdee15f1a0e85aacfb924e0e02435 upstream. wait_for_unix_gc() reads unix_tot_inflight & gc_in_progress without synchronization. Adds READ_ONCE()/WRITE_ONCE() and their associated comments to better document the intent. BUG: KCSAN: data-race in unix_inflight / wait_for_unix_gc write to 0xffffffff86e2b7c0 of 4 bytes by task 9380 on cpu 0: unix_inflight+0x1e8/0x260 net/unix/scm.c:63 unix_attach_fds+0x10c/0x1e0 net/unix/scm.c:121 unix_scm_to_skb net/unix/af_unix.c:1674 [inline] unix_dgram_sendmsg+0x679/0x16b0 net/unix/af_unix.c:1817 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffffffff86e2b7c0 of 4 bytes by task 9375 on cpu 1: wait_for_unix_gc+0x24/0x160 net/unix/garbage.c:196 unix_dgram_sendmsg+0x8e/0x16b0 net/unix/af_unix.c:1772 unix_seqpacket_sendmsg+0xcc/0x110 net/unix/af_unix.c:2258 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000002 -> 0x00000004 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 9375 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 9915672d4127 ("af_unix: limit unix_tot_inflight") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20220114164328.2038499-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06af_unix: fix races in sk_peer_pid and sk_peer_cred accessesEric Dumazet1-6/+28
[ Upstream commit 35306eb23814444bd4021f8a1c3047d3cb0c8b2b ] Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred. In order to fix this issue, this patch adds a new spinlock that needs to be used whenever these fields are read or written. Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently reading sk->sk_peer_pid which makes no sense, as this field is only possibly set by AF_UNIX sockets. We will have to clean this in a separate patch. This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback" or implementing what was truly expected. Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jann Horn <jannh@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22net/af_unix: fix a data-race in unix_dgram_pollEric Dumazet1-1/+1
commit 04f08eb44b5011493d77b602fdec29ff0f5c6cd5 upstream. syzbot reported another data-race in af_unix [1] Lets change __skb_insert() to use WRITE_ONCE() when changing skb head qlen. Also, change unix_dgram_poll() to use lockless version of unix_recvq_full() It is verry possible we can switch all/most unix_recvq_full() to the lockless version, this will be done in a future kernel version. [1] HEAD commit: 8596e589b787732c8346f0482919e83cc9362db1 BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0: __skb_insert include/linux/skbuff.h:1938 [inline] __skb_queue_before include/linux/skbuff.h:2043 [inline] __skb_queue_tail include/linux/skbuff.h:2076 [inline] skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264 unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392 ___sys_sendmsg net/socket.c:2446 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2532 __do_sys_sendmmsg net/socket.c:2561 [inline] __se_sys_sendmmsg net/socket.c:2558 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1: skb_queue_len include/linux/skbuff.h:1869 [inline] unix_recvq_full net/unix/af_unix.c:194 [inline] unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777 sock_poll+0x23e/0x260 net/socket.c:1288 vfs_poll include/linux/poll.h:90 [inline] ep_item_poll fs/eventpoll.c:846 [inline] ep_send_events fs/eventpoll.c:1683 [inline] ep_poll fs/eventpoll.c:1798 [inline] do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226 __do_sys_epoll_wait fs/eventpoll.c:2238 [inline] __se_sys_epoll_wait fs/eventpoll.c:2233 [inline] __x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000001b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G W 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 86b18aaa2b5b ("skbuff: fix a data race in skb_queue_len()") Cc: Qian Cai <cai@lca.pw> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-31af_unix: fix garbage collect vs MSG_PEEKMiklos Szeredi1-2/+49
commit cbcf01128d0a92e131bd09f1688fe032480b65ca upstream. unix_gc() assumes that candidate sockets can never gain an external reference (i.e. be installed into an fd) while the unix_gc_lock is held. Except for MSG_PEEK this is guaranteed by modifying inflight count under the unix_gc_lock. MSG_PEEK does not touch any variable protected by unix_gc_lock (file count is not), yet it needs to be serialized with garbage collection. Do this by locking/unlocking unix_gc_lock: 1) increment file count 2) lock/unlock barrier to make sure incremented file count is visible to garbage collection 3) install file into fd This is a lock barrier (unlike smp_mb()) that ensures that garbage collection is run completely before or completely after the barrier. Cc: <stable@vger.kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-23net/af_unix: fix a data-race in unix_dgram_sendmsg / unix_release_sockEric Dumazet1-3/+4
[ Upstream commit a494bd642d9120648b06bb7d28ce6d05f55a7819 ] While unix_may_send(sk, osk) is called while osk is locked, it appears unix_release_sock() can overwrite unix_peer() after this lock has been released, making KCSAN unhappy. Changing unix_release_sock() to access/change unix_peer() before lock is released should fix this issue. BUG: KCSAN: data-race in unix_dgram_sendmsg / unix_release_sock write to 0xffff88810465a338 of 8 bytes by task 20852 on cpu 1: unix_release_sock+0x4ed/0x6e0 net/unix/af_unix.c:558 unix_release+0x2f/0x50 net/unix/af_unix.c:859 __sock_release net/socket.c:599 [inline] sock_close+0x6c/0x150 net/socket.c:1258 __fput+0x25b/0x4e0 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0xae/0x130 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88810465a338 of 8 bytes by task 20888 on cpu 0: unix_may_send net/unix/af_unix.c:189 [inline] unix_dgram_sendmsg+0x923/0x1610 net/unix/af_unix.c:1712 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg net/socket.c:2516 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xffff888167905400 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 20888 Comm: syz-executor.0 Not tainted 5.13.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-16Merge tag 'net-next-5.10' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: - Add redirect_neigh() BPF packet redirect helper, allowing to limit stack traversal in common container configs and improving TCP back-pressure. Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain. - Expand netlink policy support and improve policy export to user space. (Ge)netlink core performs request validation according to declared policies. Expand the expressiveness of those policies (min/max length and bitmasks). Allow dumping policies for particular commands. This is used for feature discovery by user space (instead of kernel version parsing or trial and error). - Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge. - Allow more than 255 IPv4 multicast interfaces. - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK packets of TCPv6. - In Multi-patch TCP (MPTCP) support concurrent transmission of data on multiple subflows in a load balancing scenario. Enhance advertising addresses via the RM_ADDR/ADD_ADDR options. - Support SMC-Dv2 version of SMC, which enables multi-subnet deployments. - Allow more calls to same peer in RxRPC. - Support two new Controller Area Network (CAN) protocols - CAN-FD and ISO 15765-2:2016. - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit kernel problem. - Add TC actions for implementing MPLS L2 VPNs. - Improve nexthop code - e.g. handle various corner cases when nexthop objects are removed from groups better, skip unnecessary notifications and make it easier to offload nexthops into HW by converting to a blocking notifier. - Support adding and consuming TCP header options by BPF programs, opening the doors for easy experimental and deployment-specific TCP option use. - Reorganize TCP congestion control (CC) initialization to simplify life of TCP CC implemented in BPF. - Add support for shipping BPF programs with the kernel and loading them early on boot via the User Mode Driver mechanism, hence reusing all the user space infra we have. - Support sleepable BPF programs, initially targeting LSM and tracing. - Add bpf_d_path() helper for returning full path for given 'struct path'. - Make bpf_tail_call compatible with bpf-to-bpf calls. - Allow BPF programs to call map_update_elem on sockmaps. - Add BPF Type Format (BTF) support for type and enum discovery, as well as support for using BTF within the kernel itself (current use is for pretty printing structures). - Support listing and getting information about bpf_links via the bpf syscall. - Enhance kernel interfaces around NIC firmware update. Allow specifying overwrite mask to control if settings etc. are reset during update; report expected max time operation may take to users; support firmware activation without machine reboot incl. limits of how much impact reset may have (e.g. dropping link or not). - Extend ethtool configuration interface to report IEEE-standard counters, to limit the need for per-vendor logic in user space. - Adopt or extend devlink use for debug, monitoring, fw update in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx, dpaa2-eth). - In mlxsw expose critical and emergency SFP module temperature alarms. Refactor port buffer handling to make the defaults more suitable and support setting these values explicitly via the DCBNL interface. - Add XDP support for Intel's igb driver. - Support offloading TC flower classification and filtering rules to mscc_ocelot switches. - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as fixed interval period pulse generator and one-step timestamping in dpaa-eth. - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3) offload. - Add Lynx PHY/PCS MDIO module, and convert various drivers which have this HW to use it. Convert mvpp2 to split PCS. - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as 7-port Mediatek MT7531 IP. - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver, and wcn3680 support in wcn36xx. - Improve performance for packets which don't require much offloads on recent Mellanox NICs by 20% by making multiple packets share a descriptor entry. - Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto subtree to drivers/net. Move MDIO drivers out of the phy directory. - Clean up a lot of W=1 warnings, reportedly the actively developed subsections of networking drivers should now build W=1 warning free. - Make sure drivers don't use in_interrupt() to dynamically adapt their code. Convert tasklets to use new tasklet_setup API (sadly this conversion is not yet complete). * tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits) Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH" net, sockmap: Don't call bpf_prog_put() on NULL pointer bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo bpf, sockmap: Add locking annotations to iterator netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements net: fix pos incrementment in ipv6_route_seq_next net/smc: fix invalid return code in smcd_new_buf_create() net/smc: fix valid DMBE buffer sizes net/smc: fix use-after-free of delayed events bpfilter: Fix build error with CONFIG_BPFILTER_UMH cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info bpf: Fix register equivalence tracking. rxrpc: Fix loss of final ack on shutdown rxrpc: Fix bundle counting for exclusive connections netfilter: restore NF_INET_NUMHOOKS ibmveth: Identify ingress large send packets. ibmveth: Switch order of ibmveth_helper calls. cxgb4: handle 4-tuple PEDIT to NAT mode translation selftests: Add VRF route leaking tests ...
2020-10-14net/af_unix: Remove unused old_pid variableOr Cohen1-2/+0
Commit 109f6e39fa07c48f5801 ("af_unix: Allow SO_PEERCRED to work across namespaces.") introduced the old_pid variable in unix_listen, but it's never used. Remove the declaration and the call to put_pid. Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com> Link: https://lore.kernel.org/r/20201011153527.18628-1-orcohen@paloaltonetworks.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-01io_uring: move io_uring_get_socket() into io_uring.hJens Axboe1-0/+1
Now we have a io_uring kernel header, move this definition out of fs.h and into io_uring.h where it belongs. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-22net: unix: remove redundant assignment to variable 'err'Jing Xiangfeng1-1/+0
After commit 37ab4fa7844a ("net: unix: allow bind to fail on mutex lock"), the assignment to err is redundant. So remove it. Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
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>
2020-07-20net: make ->{get,set}sockopt in proto_ops optionalChristoph Hellwig1-6/+0
Just check for a NULL method instead of wiring up sock_no_{get,set}sockopt. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-13treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada1-2/+2
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-28net: datagram: drop 'destructor' argument from several helpersPaolo Abeni1-2/+5
The only users for such argument are the UDP protocol and the UNIX socket family. We can safely reclaim the accounted memory directly from the UDP code and, after the previous patch, we can do scm stats accounting outside the datagram helpers. Overall this cleans up a bit some datagram-related helpers, and avoids an indirect call per packet in the UDP receive path. v1 -> v2: - call scm_stat_del() only when not peeking - Kirill - fix build issue with CONFIG_INET_ESPINTCP Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28unix: uses an atomic type for scm files accountingPaolo Abeni1-15/+6
So the scm_stat_{add,del} helper can be invoked with no additional lock held. This clean-up the code a bit and will make the next patch easier. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-0/+4
The mptcp conflict was overlapping additions. The SMC conflict was an additional and removal happening at the same time. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27unix: It's CONFIG_PROC_FS not CONFIG_PROCFSDavid S. Miller1-1/+1
Fixes: 3a12500ed5dd ("unix: define and set show_fdinfo only if procfs is enabled") Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27unix: define and set show_fdinfo only if procfs is enabledTobias Klauser1-0/+4
Follow the pattern used with other *_show_fdinfo functions and only define unix_show_fdinfo and set it in proto_ops if CONFIG_PROCFS is set. Fixes: 3c32da19a858 ("unix: Show number of pending scm files of receive queue in fdinfo") Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-25af_unix: Add missing annotation for unix_wait_for_peer()Jules Irenge1-0/+1
Sparse reports a warning unix_wait_for_peer() warning: context imbalance in unix_wait_for_peer() - unexpected unlock The root cause is the missing annotation at unix_wait_for_peer() Add the missing annotation __releases(&unix_sk(other)->lock) Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-06skbuff: fix a data race in skb_queue_len()Qian Cai1-2/+9
sk_buff.qlen can be accessed concurrently as noticed by KCSAN, BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg read to 0xffff8a1b1d8a81c0 of 4 bytes by task 5371 on cpu 96: unix_dgram_sendmsg+0x9a9/0xb70 include/linux/skbuff.h:1821 net/unix/af_unix.c:1761 ____sys_sendmsg+0x33e/0x370 ___sys_sendmsg+0xa6/0xf0 __sys_sendmsg+0x69/0xf0 __x64_sys_sendmsg+0x51/0x70 do_syscall_64+0x91/0xb47 entry_SYSCALL_64_after_hwframe+0x49/0xbe write to 0xffff8a1b1d8a81c0 of 4 bytes by task 1 on cpu 99: __skb_try_recv_from_queue+0x327/0x410 include/linux/skbuff.h:2029 __skb_try_recv_datagram+0xbe/0x220 unix_dgram_recvmsg+0xee/0x850 ____sys_recvmsg+0x1fb/0x210 ___sys_recvmsg+0xa2/0xf0 __sys_recvmsg+0x66/0xf0 __x64_sys_recvmsg+0x51/0x70 do_syscall_64+0x91/0xb47 entry_SYSCALL_64_after_hwframe+0x49/0xbe Since only the read is operating as lockless, it could introduce a logic bug in unix_recvq_full() due to the load tearing. Fix it by adding a lockless variant of skb_queue_len() and unix_recvq_full() where READ_ONCE() is on the read while WRITE_ONCE() is on the write similar to the commit d7d16a89350a ("net: add skb_queue_empty_lockless()"). Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-21Merge branch 'master' of ↵David S. Miller1-3/+4
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2020-01-21 1) Add support for TCP encapsulation of IKE and ESP messages, as defined by RFC 8229. Patchset from Sabrina Dubroca. Please note that there is a merge conflict in: net/unix/af_unix.c between commit: 3c32da19a858 ("unix: Show number of pending scm files of receive queue in fdinfo") from the net-next tree and commit: b50b0580d27b ("net: add queue argument to __skb_wait_for_more_packets and __skb_{,try_}recv_datagram") from the ipsec-next tree. The conflict can be solved as done in linux-next. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-1/+1
Mere overlapping changes in the conflicts here. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-13unix: Show number of pending scm files of receive queue in fdinfoKirill Tkhai1-5/+51
Unix sockets like a block box. You never know what is stored there: there may be a file descriptor holding a mount or a block device, or there may be whole universes with namespaces, sockets with receive queues full of sockets etc. The patch adds a little debug and accounts number of files (not recursive), which is in receive queue of a unix socket. Sometimes this is useful to determine, that socket should be investigated or which task should be killed to put reference counter on a resourse. v2: Pass correct argument to lockdep Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09treewide: Use sizeof_field() macroPankaj Bharadiya1-1/+1
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
2019-12-09net: add queue argument to __skb_wait_for_more_packets and ↵Sabrina Dubroca1-3/+4
__skb_{,try_}recv_datagram This will be used by ESP over TCP to handle the queue of IKE messages. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2019-12-02Merge tag 'compat-ioctl-5.5' of ↵Linus Torvalds1-0/+19
git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...
2019-11-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-3/+3
The only slightly tricky merge conflict was the netdevsim because the mutex locking fix overlapped a lot of driver reload reorganization. The rest were (relatively) trivial in nature. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28net: use skb_queue_empty_lockless() in poll() handlersEric Dumazet1-3/+3
Many poll() handlers are lockless. Using skb_queue_empty_lockless() instead of skb_queue_empty() is more appropriate. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-23af_unix: add compat_ioctl supportArnd Bergmann1-0/+19
The af_unix protocol family has a custom ioctl command (inexplicibly based on SIOCPROTOPRIVATE), but never had a compat_ioctl handler for 32-bit applications. Since all commands are compatible here, add a trivial wrapper that performs the compat_ptr() conversion for SIOCOUTQ/SIOCINQ. SIOCUNIXFILE does not use the argument, but it doesn't hurt to also use compat_ptr() here. Fixes: ba94f3088b79 ("unix: add ioctl to open a unix socket file with O_PATH") Cc: netdev@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-12af_unix: __unix_find_socket_byname() cleanupVito Caputo1-4/+2
Remove pointless return variable dance. Appears vestigial from when the function did locking as seen in unix_find_socket_byinode(), but locking is handled in unix_find_socket_byname() for __unix_find_socket_byname(). Signed-off-by: Vito Caputo <vcaputo@pengaru.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-11/+2
Some ISDN files that got removed in net-next had some changes done in mainline, take the removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-6/+1
The phylink conflict was between a bug fix by Russell King to make sure we have a consistent PHY interface mode, and a change in net-next to pull some code in phylink_resolve() into the helper functions phylink_mac_link_{up,down}() On the dp83867 side it's mostly overlapping changes, with the 'net' side removing a condition that was supposed to trigger for RGMII but because of how it was coded never actually could trigger. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2-11/+2
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 62Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): released under the gpl version 2 or later and 1 additional normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520071858.828691433@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22net: Add UNIX_DIAG_UID to Netlink UNIX socket diagnostics.Felipe Gasper1-0/+12
This adds the ability for Netlink to report a socket's UID along with the other UNIX diagnostic information that is already available. This will allow diagnostic tools greater insight into which users control which socket. To test this, do the following as a non-root user: unshare -U -r bash nc -l -U user.socket.$$ & .. and verify from within that same session that Netlink UNIX socket diagnostics report the socket's UID as 0. Also verify that Netlink UNIX socket diagnostics report the socket's UID as the user's UID from an unprivileged process in a different session. Verify the same from a root process. Signed-off-by: Felipe Gasper <felipe@felipegasper.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-08datagram: remove rendundant 'peeked' argumentPaolo Abeni1-3/+3
After commit a297569fe00a ("net/udp: do not touch skb->peeked unless really needed") the 'peeked' argument of __skb_try_recv_datagram() and friends is always equal to !!'flags & MSG_PEEK'. Since such argument is really a boolean info, and the callers have already 'flags & MSG_PEEK' handy, we can remove it and clean-up the code a bit. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-09Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-blockLinus Torvalds6-127/+172
Pull io_uring IO interface from Jens Axboe: "Second attempt at adding the io_uring interface. Since the first one, we've added basic unit testing of the three system calls, that resides in liburing like the other unit tests that we have so far. It'll take a while to get full coverage of it, but we're working towards it. I've also added two basic test programs to tools/io_uring. One uses the raw interface and has support for all the various features that io_uring supports outside of standard IO, like fixed files, fixed IO buffers, and polled IO. The other uses the liburing API, and is a simplified version of cp(1). This adds support for a new IO interface, io_uring. io_uring allows an application to communicate with the kernel through two rings, the submission queue (SQ) and completion queue (CQ) ring. This allows for very efficient handling of IOs, see the v5 posting for some basic numbers: https://lore.kernel.org/linux-block/20190116175003.17880-1-axboe@kernel.dk/ Outside of just efficiency, the interface is also flexible and extendable, and allows for future use cases like the upcoming NVMe key-value store API, networked IO, and so on. It also supports async buffered IO, something that we've always failed to support in the kernel. Outside of basic IO features, it supports async polled IO as well. This particular feature has already been tested at Facebook months ago for flash storage boxes, with 25-33% improvements. It makes polled IO actually useful for real world use cases, where even basic flash sees a nice win in terms of efficiency, latency, and performance. These boxes were IOPS bound before, now they are not. This series adds three new system calls. One for setting up an io_uring instance (io_uring_setup(2)), one for submitting/completing IO (io_uring_enter(2)), and one for aux functions like registrating file sets, buffers, etc (io_uring_register(2)). Through the help of Arnd, I've coordinated the syscall numbers so merge on that front should be painless. Jon did a writeup of the interface a while back, which (except for minor details that have been tweaked) is still accurate. Find that here: https://lwn.net/Articles/776703/ Huge thanks to Al Viro for helping getting the reference cycle code correct, and to Jann Horn for his extensive reviews focused on both security and bugs in general. There's a userspace library that provides basic functionality for applications that don't need or want to care about how to fiddle with the rings directly. It has helpers to allow applications to easily set up an io_uring instance, and submit/complete IO through it without knowing about the intricacies of the rings. It also includes man pages (thanks to Jeff Moyer), and will continue to grow support helper functions and features as time progresses. Find it here: git://git.kernel.dk/liburing Fio has full support for the raw interface, both in the form of an IO engine (io_uring), but also with a small test application (t/io_uring) that can exercise and benchmark the interface" * tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block: io_uring: add a few test tools io_uring: allow workqueue item to handle multiple buffered requests io_uring: add support for IORING_OP_POLL io_uring: add io_kiocb ref count io_uring: add submission polling io_uring: add file set registration net: split out functions related to registering inflight socket files io_uring: add support for pre-mapped user IO buffers block: implement bio helper to add iter bvec pages to bio io_uring: batch io_kiocb allocation io_uring: use fget/fput_many() for file references fs: add fget_many() and fput_many() io_uring: support for IO polling io_uring: add fsync support Add io_uring IO interface
2019-02-28net: split out functions related to registering inflight socket filesJens Axboe6-130/+172
We need this functionality for the io_uring file registration, but we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers to a separate file, that's always builtin to the kernel if CONFIG_UNIX is m/y. No functional changes in this patch, just moving code around. Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28Add io_uring IO interfaceJens Axboe1-0/+3
The submission queue (SQ) and completion queue (CQ) rings are shared between the application and the kernel. This eliminates the need to copy data back and forth to submit and complete IO. IO submissions use the io_uring_sqe data structure, and completions are generated in the form of io_uring_cqe data structures. The SQ ring is an index into the io_uring_sqe array, which makes it possible to submit a batch of IOs without them being contiguous in the ring. The CQ ring is always contiguous, as completion events are inherently unordered, and hence any io_uring_cqe entry can point back to an arbitrary submission. Two new system calls are added for this: io_uring_setup(entries, params) Sets up an io_uring instance for doing async IO. On success, returns a file descriptor that the application can mmap to gain access to the SQ ring, CQ ring, and io_uring_sqes. io_uring_enter(fd, to_submit, min_complete, flags, sigset, sigsetsize) Initiates IO against the rings mapped to this fd, or waits for them to complete, or both. The behavior is controlled by the parameters passed in. If 'to_submit' is non-zero, then we'll try and submit new IO. If IORING_ENTER_GETEVENTS is set, the kernel will wait for 'min_complete' events, if they aren't already available. It's valid to set IORING_ENTER_GETEVENTS and 'min_complete' == 0 at the same time, this allows the kernel to return already completed events without waiting for them. This is useful only for polling, as for IRQ driven IO, the application can just check the CQ ring without entering the kernel. With this setup, it's possible to do async IO with a single system call. Future developments will enable polled IO with this interface, and polled submission as well. The latter will enable an application to do IO without doing ANY system calls at all. For IRQ driven IO, an application only needs to enter the kernel for completions if it wants to wait for them to occur. Each io_uring is backed by a workqueue, to support buffered async IO as well. We will only punt to an async context if the command would need to wait for IO on the device side. Any data that can be accessed directly in the page cache is done inline. This avoids the slowness issue of usual threadpools, since cached data is accessed as quickly as a sync interface. Sample application: http://git.kernel.dk/cgit/fio/plain/t/io_uring.c Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-21missing barriers in some of unix_sock ->addr and ->path accessesAl Viro2-25/+35
Several u->addr and u->path users are not holding any locks in common with unix_bind(). unix_state_lock() is useless for those purposes. u->addr is assign-once and *(u->addr) is fully set up by the time we set u->addr (all under unix_table_lock). u->path is also set in the same critical area, also before setting u->addr, and any unix_sock with ->path filled will have non-NULL ->addr. So setting ->addr with smp_store_release() is all we need for those "lockless" users - just have them fetch ->addr with smp_load_acquire() and don't even bother looking at ->path if they see NULL ->addr. Users of ->addr and ->path fall into several classes now: 1) ones that do smp_load_acquire(u->addr) and access *(u->addr) and u->path only if smp_load_acquire() has returned non-NULL. 2) places holding unix_table_lock. These are guaranteed that *(u->addr) is seen fully initialized. If unix_sock is in one of the "bound" chains, so's ->path. 3) unix_sock_destructor() using ->addr is safe. All places that set u->addr are guaranteed to have seen all stores *(u->addr) while holding a reference to u and unix_sock_destructor() is called when (atomic) refcount hits zero. 4) unix_release_sock() using ->path is safe. unix_bind() is serialized wrt unix_release() (normally - by struct file refcount), and for the instances that had ->path set by unix_bind() unix_release_sock() comes from unix_release(), so they are fine. Instances that had it set in unix_stream_connect() either end up attached to a socket (in unix_accept()), in which case the call chain to unix_release_sock() and serialization are the same as in the previous case, or they never get accept'ed and unix_release_sock() is called when the listener is shut down and its queue gets purged. In that case the listener's queue lock provides the barriers needed - unix_stream_connect() shoves our unix_sock into listener's queue under that lock right after having set ->path and eventual unix_release_sock() caller picks them from that queue under the same lock right before calling unix_release_sock(). 5) unix_find_other() use of ->path is pointless, but safe - it happens with successful lookup by (abstract) name, so ->path.dentry is guaranteed to be NULL there. earlier-variant-reviewed-by: "Paul E. McKenney" <paulmck@linux.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>