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2024-09-12af_unix: Remove put_pid()/put_cred() in copy_peercred().Kuniyuki Iwashima
[ Upstream commit e4bd881d987121dbf1a288641491955a53d9f8f7 ] When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket, the listener's sk_peer_pid/sk_peer_cred are copied to the client in copy_peercred(). Then, the client's sk_peer_pid and sk_peer_cred are always NULL, so we need not call put_pid() and put_cred() there. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05af_unix: Use unix_recvq_full_lockless() in unix_stream_connect().Kuniyuki Iwashima
[ Upstream commit 45d872f0e65593176d880ec148f41ad7c02e40a7 ] Once sk->sk_state is changed to TCP_LISTEN, it never changes. unix_accept() takes advantage of this characteristics; it does not hold the listener's unix_state_lock() and only acquires recvq lock to pop one skb. It means unix_state_lock() does not prevent the queue length from changing in unix_stream_connect(). Thus, we need to use unix_recvq_full_lockless() to avoid data-race. Now we remove unix_recvq_full() as no one uses it. Note that we can remove READ_ONCE() for sk->sk_max_ack_backlog in unix_recvq_full_lockless() because of the following reasons: (1) For SOCK_DGRAM, it is a written-once field in unix_create1() (2) For SOCK_STREAM and SOCK_SEQPACKET, it is changed under the listener's unix_state_lock() in unix_listen(), and we hold the lock in unix_stream_connect() Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05af_unix: Annotate data-race of net->unx.sysctl_max_dgram_qlen.Kuniyuki Iwashima
[ Upstream commit bd9f2d05731f6a112d0c7391a0d537bfc588dbe6 ] net->unx.sysctl_max_dgram_qlen is exposed as a sysctl knob and can be changed concurrently. Let's use READ_ONCE() in unix_create1(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05af_unix: Annotate data-races around sk->sk_state in sendmsg() and recvmsg().Kuniyuki Iwashima
[ Upstream commit 8a34d4e8d9742a24f74998f45a6a98edd923319b ] The following functions read sk->sk_state locklessly and proceed only if the state is TCP_ESTABLISHED. * unix_stream_sendmsg * unix_stream_read_generic * unix_seqpacket_sendmsg * unix_seqpacket_recvmsg Let's use READ_ONCE() there. Fixes: a05d2ad1c1f3 ("af_unix: Only allow recv on connected seqpacket sockets.") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05af_unix: Annotate data-races around sk->sk_state in unix_write_space() and ↵Kuniyuki Iwashima
poll(). [ Upstream commit eb0718fb3e97ad0d6f4529b810103451c90adf94 ] unix_poll() and unix_dgram_poll() read sk->sk_state locklessly and calls unix_writable() which also reads sk->sk_state without holding unix_state_lock(). Let's use READ_ONCE() in unix_poll() and unix_dgram_poll() and pass it to unix_writable(). While at it, we remove TCP_SYN_SENT check in unix_dgram_poll() as that state does not exist for AF_UNIX socket since the code was added. Fixes: 1586a5877db9 ("af_unix: do not report POLLOUT on listeners") Fixes: 3c73419c09a5 ("af_unix: fix 'poll for write'/ connected DGRAM sockets") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05af_unix: Annotate data-race of sk->sk_state in unix_inq_len().Kuniyuki Iwashima
[ Upstream commit 3a0f38eb285c8c2eead4b3230c7ac2983707599d ] ioctl(SIOCINQ) calls unix_inq_len() that checks sk->sk_state first and returns -EINVAL if it's TCP_LISTEN. Then, for SOCK_STREAM sockets, unix_inq_len() returns the number of bytes in recvq. However, unix_inq_len() does not hold unix_state_lock(), and the concurrent listen() might change the state after checking sk->sk_state. If the race occurs, 0 is returned for the listener, instead of -EINVAL, because the length of skb with embryo is 0. We could hold unix_state_lock() in unix_inq_len(), but it's overkill given the result is true for pre-listen() TCP_CLOSE state. So, let's use READ_ONCE() for sk->sk_state in unix_inq_len(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16af_unix: Fix data races in unix_release_sock/unix_stream_sendmsgBreno Leitao
[ Upstream commit 540bf24fba16b88c1b3b9353927204b4f1074e25 ] A data-race condition has been identified in af_unix. In one data path, the write function unix_release_sock() atomically writes to sk->sk_shutdown using WRITE_ONCE. However, on the reader side, unix_stream_sendmsg() does not read it atomically. Consequently, this issue is causing the following KCSAN splat to occur: BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28: unix_release_sock (net/unix/af_unix.c:640) unix_release (net/unix/af_unix.c:1050) sock_close (net/socket.c:659 net/socket.c:1421) __fput (fs/file_table.c:422) __fput_sync (fs/file_table.c:508) __se_sys_close (fs/open.c:1559 fs/open.c:1541) __x64_sys_close (fs/open.c:1541) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14: unix_stream_sendmsg (net/unix/af_unix.c:2273) __sock_sendmsg (net/socket.c:730 net/socket.c:745) ____sys_sendmsg (net/socket.c:2584) __sys_sendmmsg (net/socket.c:2638 net/socket.c:2724) __x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x01 -> 0x03 The line numbers are related to commit dd5a440a31fa ("Linux 6.9-rc7"). Commit e1d09c2c2f57 ("af_unix: Fix data races around sk->sk_shutdown.") addressed a comparable issue in the past regarding sk->sk_shutdown. However, it overlooked resolving this particular data path. This patch only offending unix_stream_sendmsg() function, since the other reads seem to be protected by unix_state_lock() as discussed in Link: https://lore.kernel.org/all/20240508173324.53565-1-kuniyu@amazon.com/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240509081459.2807828-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-02af_unix: Do not use atomic ops for unix_sk(sk)->inflight.Kuniyuki Iwashima
[ Upstream commit 97af84a6bba2ab2b9c704c08e67de3b5ea551bb2 ] When touching unix_sk(sk)->inflight, we are always under spin_lock(&unix_gc_lock). Let's convert unix_sk(sk)->inflight to the normal unsigned long. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240123170856.41348-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23af_unix: fix lockdep positive in sk_diag_dump_icons()Eric Dumazet
[ Upstream commit 4d322dce82a1d44f8c83f0f54f95dd1b8dcf46c9 ] syzbot reported a lockdep splat [1]. Blamed commit hinted about the possible lockdep violation, and code used unix_state_lock_nested() in an attempt to silence lockdep. It is not sufficient, because unix_state_lock_nested() is already used from unix_state_double_lock(). We need to use a separate subclass. This patch adds a distinct enumeration to make things more explicit. Also use swap() in unix_state_double_lock() as a clean up. v2: add a missing inline keyword to unix_state_lock_nested() [1] WARNING: possible circular locking dependency detected 6.8.0-rc1-syzkaller-00356-g8a696a29c690 #0 Not tainted syz-executor.1/2542 is trying to acquire lock: ffff88808b5df9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863 but task is already holding lock: ffff88808b5dfe70 (&u->lock/1){+.+.}-{2:2}, at: unix_dgram_sendmsg+0xfc7/0x2200 net/unix/af_unix.c:2089 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&u->lock/1){+.+.}-{2:2}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 sk_diag_dump_icons net/unix/diag.c:87 [inline] sk_diag_fill+0x6ea/0xfe0 net/unix/diag.c:157 sk_diag_dump net/unix/diag.c:196 [inline] unix_diag_dump+0x3e9/0x630 net/unix/diag.c:220 netlink_dump+0x5c1/0xcd0 net/netlink/af_netlink.c:2264 __netlink_dump_start+0x5d7/0x780 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:338 [inline] unix_diag_handler_dump+0x1c3/0x8f0 net/unix/diag.c:319 sock_diag_rcv_msg+0xe3/0x400 netlink_rcv_skb+0x1df/0x430 net/netlink/af_netlink.c:2543 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7e6/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa37/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x39a/0x520 net/socket.c:1160 call_write_iter include/linux/fs.h:2085 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa74/0xca0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b -> #0 (rlock-AF_UNIX){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863 unix_dgram_sendmsg+0x15d9/0x2200 net/unix/af_unix.c:2112 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2753 [inline] __se_sys_sendmmsg net/socket.c:2750 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&u->lock/1); lock(rlock-AF_UNIX); lock(&u->lock/1); lock(rlock-AF_UNIX); *** DEADLOCK *** 1 lock held by syz-executor.1/2542: #0: ffff88808b5dfe70 (&u->lock/1){+.+.}-{2:2}, at: unix_dgram_sendmsg+0xfc7/0x2200 net/unix/af_unix.c:2089 stack backtrace: CPU: 1 PID: 2542 Comm: syz-executor.1 Not tainted 6.8.0-rc1-syzkaller-00356-g8a696a29c690 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x366/0x490 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+0x1909/0x5ab0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 skb_queue_tail+0x36/0x120 net/core/skbuff.c:3863 unix_dgram_sendmsg+0x15d9/0x2200 net/unix/af_unix.c:2112 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x592/0x890 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724 __do_sys_sendmmsg net/socket.c:2753 [inline] __se_sys_sendmmsg net/socket.c:2750 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f26d887cda9 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:00007f26d95a60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f26d89abf80 RCX: 00007f26d887cda9 RDX: 000000000000003e RSI: 00000000200bd000 RDI: 0000000000000004 RBP: 00007f26d88c947a R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000008c0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f26d89abf80 R15: 00007ffcfe081a68 Fixes: 2aac7a2cb0d9 ("unix_diag: Pending connections IDs NLA") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240130184235.1620738-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23af_unix: Fix data-race around unix_tot_inflight.Kuniyuki Iwashima
[ 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>
2023-08-30af_unix: Fix null-ptr-deref in unix_stream_sendpage().Kuniyuki Iwashima
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 Dumazet
[ 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 Iwashima
[ 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 Iwashima
[ 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>
2022-06-14af_unix: Fix a data-race in unix_dgram_peer_wake_me().Kuniyuki Iwashima
[ 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>
2021-10-06af_unix: fix races in sk_peer_pid and sk_peer_cred accessesEric Dumazet
[ 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 Dumazet
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 Szeredi
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 Dumazet
[ 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>
2020-10-01skbuff: fix a data race in skb_queue_len()Qian Cai
[ Upstream commit 86b18aaa2b5b5bb48e609cd591b3d2d0fdbe0442 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-17af_unix: add compat_ioctl supportArnd Bergmann
commit 5f6beb9e0f633f3cc845cdd67973c506372931b4 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-28net: use skb_queue_empty_lockless() in poll() handlersEric Dumazet
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>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
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>
2019-04-08datagram: remove rendundant 'peeked' argumentPaolo Abeni
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>
2019-03-08Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-blockLinus Torvalds
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 Axboe
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>
2019-02-20missing barriers in some of unix_sock ->addr and ->path accessesAl Viro
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>
2018-10-23Revert "net: simplify sock_poll_wait"Karsten Graul
This reverts commit dd979b4df817e9976f18fb6f9d134d6bc4a3c317. This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an internal TCP socket for the initial handshake with the remote peer. Whenever the SMC connection can not be established this TCP socket is used as a fallback. All socket operations on the SMC socket are then forwarded to the TCP socket. In case of poll, the file->private_data pointer references the SMC socket because the TCP socket has no file assigned. This causes tcp_poll to wait on the wrong socket. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-17net: fix warning in af_unixKyeongdon Kim
This fixes the "'hash' may be used uninitialized in this function" net/unix/af_unix.c:1041:20: warning: 'hash' may be used uninitialized in this function [-Wmaybe-uninitialized] addr->hash = hash ^ sk->sk_type; Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03af_unix: ensure POLLOUT on remote close() for connected dgram socketJason Baron
Applications use -ECONNREFUSED as returned from write() in order to determine that a socket should be closed. However, when using connected dgram unix sockets in a poll/write loop, a final POLLOUT event can be missed when the remote end closes. Thus, the poll is stuck forever: thread 1 (client) thread 2 (server) connect() to server write() returns -EAGAIN unix_dgram_poll() -> unix_recvq_full() is true close() ->unix_release_sock() ->wake_up_interruptible_all() unix_dgram_poll() (due to the wake_up_interruptible_all) -> unix_recvq_full() still is true ->free all skbs Now thread 1 is stuck and will not receive anymore wakeups. In this case, when thread 1 gets the -EAGAIN, it has not queued any skbs otherwise the 'free all skbs' step would in fact cause a wakeup and a POLLOUT return. So the race here is probably fairly rare because it means there are no skbs that thread 1 queued and that thread 1 schedules before the 'free all skbs' step. This issue was reported as a hang when /dev/log is closed. The fix is to signal POLLOUT if the socket is marked as SOCK_DEAD, which means a subsequent write() will get -ECONNREFUSED. Reported-by: Ian Lance Taylor <iant@golang.org> Cc: David Rientjes <rientjes@google.com> Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30net: simplify sock_poll_waitChristoph Hellwig
The wait_address argument is always directly derived from the filp argument, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLLLinus Torvalds
The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-04Merge branch 'work.aio-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-05-26net/unix: convert to ->poll_maskChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16proc: introduce proc_create_net{,_data}Christoph Hellwig
Variants of proc_create{,_data} that directly take a struct seq_operations and deal with network namespaces in ->open and ->release. All callers of proc_create + seq_open_net converted over, and seq_{open,release}_net are removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-04-04af_unix: remove redundant lockdep classCong Wang
After commit 581319c58600 ("net/socket: use per af lockdep classes for sk queues") sock queue locks now have per-af lockdep classes, including unix socket. It is no longer necessary to workaround it. I noticed this while looking at a syzbot deadlock report, this patch itself doesn't fix it (this is why I don't add Reported-by). Fixes: 581319c58600 ("net/socket: use per af lockdep classes for sk queues") Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2018-02-13net: af_unix: fix typo in UNIX_SKB_FRAGS_SZ commentTobias Klauser
Change "minimun" to "minimum". Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-13net: Convert unix_net_opsKirill Tkhai
These pernet_operations are just create and destroy /proc and sysctl entries, and are not touched by foreign pernet_operations. So, we are able to make them async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-12net: make getname() functions return length rather than use int* parameterDenys Vlasenko
Changes since v1: Added changes in these files: drivers/infiniband/hw/usnic/usnic_transport.c drivers/staging/lustre/lnet/lnet/lib-socket.c drivers/target/iscsi/iscsi_target_login.c drivers/vhost/net.c fs/dlm/lowcomms.c fs/ocfs2/cluster/tcp.c security/tomoyo/network.c Before: All these functions either return a negative error indicator, or store length of sockaddr into "int *socklen" parameter and return zero on success. "int *socklen" parameter is awkward. For example, if caller does not care, it still needs to provide on-stack storage for the value it does not need. None of the many FOO_getname() functions of various protocols ever used old value of *socklen. They always just overwrite it. This change drops this parameter, and makes all these functions, on success, return length of sockaddr. It's always >= 0 and can be differentiated from an error. Tests in callers are changed from "if (err)" to "if (err < 0)", where needed. rpc_sockname() lost "int buflen" parameter, since its only use was to be passed to kernel_getsockname() as &buflen and subsequently not used in any way. Userspace API is not changed. text data bss dec hex filename 30108430 2633624 873672 33615726 200ef6e vmlinux.before.o 30108109 2633612 873672 33615393 200ee21 vmlinux.o Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: David S. Miller <davem@davemloft.net> CC: linux-kernel@vger.kernel.org CC: netdev@vger.kernel.org CC: linux-bluetooth@vger.kernel.org CC: linux-decnet-user@lists.sourceforge.net CC: linux-wireless@vger.kernel.org CC: linux-rdma@vger.kernel.org CC: linux-sctp@vger.kernel.org CC: linux-nfs@vger.kernel.org CC: linux-x25@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Significantly shrink the core networking routing structures. Result of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf 2) Add netdevsim driver for testing various offloads, from Jakub Kicinski. 3) Support cross-chip FDB operations in DSA, from Vivien Didelot. 4) Add a 2nd listener hash table for TCP, similar to what was done for UDP. From Martin KaFai Lau. 5) Add eBPF based queue selection to tun, from Jason Wang. 6) Lockless qdisc support, from John Fastabend. 7) SCTP stream interleave support, from Xin Long. 8) Smoother TCP receive autotuning, from Eric Dumazet. 9) Lots of erspan tunneling enhancements, from William Tu. 10) Add true function call support to BPF, from Alexei Starovoitov. 11) Add explicit support for GRO HW offloading, from Michael Chan. 12) Support extack generation in more netlink subsystems. From Alexander Aring, Quentin Monnet, and Jakub Kicinski. 13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From Russell King. 14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso. 15) Many improvements and simplifications to the NFP driver bpf JIT, from Jakub Kicinski. 16) Support for ipv6 non-equal cost multipath routing, from Ido Schimmel. 17) Add resource abstration to devlink, from Arkadi Sharshevsky. 18) Packet scheduler classifier shared filter block support, from Jiri Pirko. 19) Avoid locking in act_csum, from Davide Caratti. 20) devinet_ioctl() simplifications from Al viro. 21) More TCP bpf improvements from Lawrence Brakmo. 22) Add support for onlink ipv6 route flag, similar to ipv4, from David Ahern. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits) tls: Add support for encryption using async offload accelerator ip6mr: fix stale iterator net/sched: kconfig: Remove blank help texts openvswitch: meter: Use 64-bit arithmetic instead of 32-bit tcp_nv: fix potential integer overflow in tcpnv_acked r8169: fix RTL8168EP take too long to complete driver initialization. qmi_wwan: Add support for Quectel EP06 rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK ipmr: Fix ptrdiff_t print formatting ibmvnic: Wait for device response when changing MAC qlcnic: fix deadlock bug tcp: release sk_frag.page in tcp_disconnect ipv4: Get the address of interface correctly. net_sched: gen_estimator: fix lockdep splat net: macb: Handle HRESP error net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring ipv6: addrconf: break critical section in addrconf_verify_rtnl() ipv6: change route cache aging logic i40e/i40evf: Update DESC_NEEDED value to reflect larger value bnxt_en: cleanup DIM work on device shutdown ...
2018-01-16net: delete /proc THIS_MODULE referencesAlexey Dobriyan
/proc has been ignoring struct file_operations::owner field for 10 years. Specifically, it started with commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba ("Fix rmmod/read/write races in /proc entries"). Notice the chunk where inode->i_fop is initialized with proxy struct file_operations for regular files: - if (de->proc_fops) - inode->i_fop = de->proc_fops; + if (de->proc_fops) { + if (S_ISREG(inode->i_mode)) + inode->i_fop = &proc_reg_file_ops; + else + inode->i_fop = de->proc_fops; + } VFS stopped pinning module at this point. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-27net: annotate ->poll() instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27annotate poll-related wait keysAl Viro
__poll_t is also used as wait key in some waitqueues. Verify that wait_..._poll() gets __poll_t as key and provide a helper for wakeup functions to get back to that __poll_t value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-10-22net: af_unix: mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2017-08-18datagram: When peeking datagrams with offset < 0 don't skip empty skbsMatthew Dawson
Due to commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac ("udp: remove headers from UDP packets before queueing"), when udp packets are being peeked the requested extra offset is always 0 as there is no need to skip the udp header. However, when the offset is 0 and the next skb is of length 0, it is only returned once. The behaviour can be seen with the following python script: from socket import *; f=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); g=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); f.bind(('::', 0)); addr=('::1', f.getsockname()[1]); g.sendto(b'', addr) g.sendto(b'b', addr) print(f.recvfrom(10, MSG_PEEK)); print(f.recvfrom(10, MSG_PEEK)); Where the expected output should be the empty string twice. Instead, make sk_peek_offset return negative values, and pass those values to __skb_try_recv_datagram/__skb_try_recv_from_queue. If the passed offset to __skb_try_recv_from_queue is negative, the checked skb is never skipped. __skb_try_recv_from_queue will then ensure the offset is reset back to 0 if a peek is requested without an offset, unless no packets are found. Also simplify the if condition in __skb_try_recv_from_queue. If _off is greater then 0, and off is greater then or equal to skb->len, then (_off || skb->len) must always be true assuming skb->len >= 0 is always true. Also remove a redundant check around a call to sk_peek_offset in af_unix.c, as it double checked if MSG_PEEK was set in the flags. V2: - Moved the negative fixup into __skb_try_recv_from_queue, and remove now redundant checks - Fix peeking in udp{,v6}_recvmsg to report the right value when the offset is 0 V3: - Marked new branch in __skb_try_recv_from_queue as unlikely. Signed-off-by: Matthew Dawson <matthew@mjdsystems.ca> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17net/unix: drop obsolete fd-recursion limitsDavid Herrmann
All unix sockets now account inflight FDs to the respective sender. This was introduced in: commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 Author: willy tarreau <w@1wt.eu> Date: Sun Jan 10 07:54:56 2016 +0100 unix: properly account for FDs passed over unix sockets and further refined in: commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 Author: Hannes Frederic Sowa <hannes@stressinduktion.org> Date: Wed Feb 3 02:11:03 2016 +0100 unix: correctly track in-flight fds in sending process user_struct Hence, regardless of the stacking depth of FDs, the total number of inflight FDs is limited, and accounted. There is no known way for a local user to exceed those limits or exploit the accounting. Furthermore, the GC logic is independent of the recursion/stacking depth as well. It solely depends on the total number of inflight FDs, regardless of their layout. Lastly, the current `recursion_level' suffers a TOCTOU race, since it checks and inherits depths only at queue time. If we consider `A<-B' to mean `queue-B-on-A', the following sequence circumvents the recursion level easily: A<-B B<-C C<-D ... Y<-Z resulting in: A<-B<-C<-...<-Z With all of this in mind, lets drop the recursion limit. It has no additional security value, anymore. On the contrary, it randomly confuses message brokers that try to forward file-descriptors, since any sendmsg(2) call can fail spuriously with ETOOMANYREFS if a client maliciously modifies the FD while inflight. Cc: Alban Crequy <alban.crequy@collabora.co.uk> Cc: Simon McVittie <simon.mcvittie@collabora.co.uk> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David S. Miller <davem@davemloft.net>