Eric Dumazet
4d322dce82
af_unix: fix lockdep positive in sk_diag_dump_icons()
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: 2aac7a2cb0 ("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>
2024-01-31 17:51:55 -08:00
..
2023-03-27 02:33:48 +00:00
2023-12-22 12:56:21 -05:00
2023-08-10 18:24:48 -07:00
2023-12-29 07:46:38 +00:00
2024-01-12 13:52:21 -08:00
2024-01-24 19:50:20 +01:00
2023-12-15 11:01:27 +00:00
2021-11-17 20:17:05 -08:00
2023-12-17 10:56:33 +00:00
2023-06-15 22:33:26 -07:00
2023-08-10 19:31:52 -07:00
2024-01-02 12:41:16 +00:00
2024-01-07 14:58:26 +00:00
2023-12-08 10:40:51 +00:00
2023-12-24 15:22:50 +00:00
2024-01-31 17:51:55 -08:00
2023-12-15 10:37:35 +00:00
2022-07-22 12:53:22 +01:00
2023-03-21 21:32:18 -07:00
2023-03-18 12:23:34 +00:00
2022-08-09 22:14:02 -07:00
2021-12-13 12:34:09 +00:00
2023-07-28 18:06:30 -07:00
2022-11-02 20:38:13 -07:00
2022-07-22 12:53:22 +01:00
2023-08-24 10:07:13 +02:00
2021-03-26 17:43:55 +01:00
2023-08-03 08:38:07 -07:00
2022-11-16 11:31:47 +02:00
2023-12-21 20:35:14 +01:00
2023-12-15 11:14:57 +01:00
2023-01-27 11:19:46 +00:00
2021-12-22 15:03:47 -08:00
2022-07-22 12:53:22 +01:00
2023-07-14 20:39:29 -07:00
2022-07-24 18:39:17 -06:00
2023-07-27 17:17:32 -07:00
2022-07-22 12:53:22 +01:00
2023-01-20 09:33:22 +00:00
2023-10-20 11:34:51 +01:00
2023-12-20 11:50:13 +00:00
2023-08-14 08:01:06 +01:00
2023-10-24 13:08:14 -07:00
2023-10-24 13:08:14 -07:00
2021-11-29 19:50:45 -08:00
2022-12-05 21:58:27 -08:00
2023-08-22 13:19:02 +02:00
2023-10-25 18:04:29 -07:00
2022-07-22 12:53:22 +01:00
2022-07-22 12:53:22 +01:00
2022-07-22 12:53:22 +01:00
2021-12-06 16:06:02 -08:00
2024-01-03 16:42:48 -08:00
2022-07-28 22:21:54 -07:00
2023-08-02 10:09:31 +01:00
2023-10-06 11:37:02 +01:00
2023-11-02 09:31:02 +01:00
2023-04-12 16:40:39 -07:00
2022-12-01 15:09:10 +01:00
2023-08-08 15:58:23 -07:00
2022-07-22 12:53:22 +01:00
2021-10-18 12:54:41 +01:00
2023-12-29 08:43:59 +00:00
2022-10-31 10:43:04 +00:00
2021-01-29 20:39:14 -08:00
2023-10-06 07:30:40 +02:00
2023-06-10 00:11:41 -07:00
2022-07-22 12:53:22 +01:00
2022-07-22 12:53:22 +01:00
2023-07-28 14:07:59 -07:00
2022-07-22 12:53:22 +01:00
2021-06-28 14:29:45 -07:00
2023-10-12 15:14:27 +03:00
2023-11-20 11:43:03 +01:00
2023-12-08 10:40:51 +00:00
2022-07-22 12:53:22 +01:00
2023-08-15 13:57:51 -07:00
2023-08-14 07:06:13 +01:00
2024-01-19 21:13:25 -08:00
2022-02-07 20:12:45 -08:00
2021-10-15 11:33:08 +01:00
2023-07-14 20:39:29 -07:00
2023-12-22 22:15:35 +00:00
2024-01-21 18:09:30 +00:00
2023-12-22 22:15:35 +00:00
2022-02-17 07:00:39 -06:00
2021-11-16 13:16:54 +00:00
2023-12-21 22:16:47 +01:00
2023-09-19 18:21:44 +02:00
2022-04-25 11:40:45 +01:00
2023-10-05 13:16:47 -07:00
2023-11-16 22:33:31 +00:00
2023-04-22 01:39:41 +02:00
2024-01-26 21:05:26 -08:00
2022-09-29 07:18:00 +02:00
2022-07-22 12:53:22 +01:00
2022-10-31 20:14:27 -07:00
2023-10-30 14:36:57 -07:00
2023-12-22 22:15:34 +00:00
2023-08-22 21:40:40 +02:00
2023-06-12 21:13:23 -07:00
2021-03-23 14:14:50 -07:00
2023-08-04 15:33:17 -07:00
2023-08-04 15:33:17 -07:00
2022-07-22 12:53:22 +01:00
2023-07-20 10:46:28 +02:00
2021-10-13 09:40:46 -07:00
2024-01-19 21:30:09 -08:00
2022-07-22 12:53:22 +01:00
2022-07-22 12:53:22 +01:00
2022-07-28 11:29:36 +02:00
2021-11-07 19:25:29 +00:00
2023-08-18 16:05:26 +02:00
2023-12-21 20:35:15 +01:00
2022-10-12 12:57:19 +02:00
2023-12-27 13:08:10 +00:00
2023-06-20 20:06:16 -07:00
2021-10-29 13:23:51 +01:00
2021-03-26 15:14:56 -07:00
2022-07-22 12:53:22 +01:00
2023-08-22 17:31:18 -07:00
2022-11-18 12:14:55 +00:00
2022-07-22 12:53:22 +01:00
2023-08-07 08:53:55 +01:00
2023-11-28 12:18:29 +01:00
2022-05-11 12:43:10 +01:00
2023-10-18 09:23:01 +01:00
2021-12-10 06:38:26 -08:00
2024-01-13 18:26:23 +00:00
2023-12-04 18:04:05 -08:00
2022-07-22 12:53:22 +01:00
2023-11-20 10:15:16 -08:00
2023-12-19 15:31:40 +01:00
2022-07-22 12:53:22 +01:00
2023-10-06 10:50:34 +01:00
2023-11-20 11:43:45 +01:00
2023-07-14 20:39:29 -07:00
2023-08-04 15:33:50 -07:00
2023-07-14 20:39:30 -07:00
2023-06-02 09:55:22 +01:00
2023-12-20 11:50:13 +00:00
2023-12-20 11:50:13 +00:00
2022-07-22 12:53:22 +01:00
2022-07-15 18:50:35 -07:00
2021-08-09 15:34:21 -07:00
2022-07-22 12:53:22 +01:00
2023-04-06 12:01:20 -07:00
2023-03-17 08:56:37 +00:00
2022-10-11 17:42:58 -06:00
2023-09-18 09:44:05 +02:00
2022-02-02 14:45:18 +00:00
2022-08-01 11:59:23 -07:00
2023-10-16 09:57:52 +01:00
2023-06-19 11:32:58 -07:00
2023-07-14 20:39:30 -07:00
2023-08-20 11:40:03 +01:00
2024-01-24 01:33:59 +00:00
2023-12-12 14:24:14 +01:00
2022-07-22 12:53:22 +01:00
2022-01-04 12:17:35 +00:00
2021-04-28 14:06:45 -07:00
2023-12-26 20:24:33 +00:00
2022-10-25 11:35:16 +02:00
2024-01-21 18:09:30 +00:00
2023-10-04 11:49:20 -07:00
2022-07-22 12:53:22 +01:00
2022-07-18 11:24:10 +01:00
2023-08-09 13:12:15 -07:00
2024-01-02 12:41:16 +00:00
2024-01-04 18:06:46 -08:00
2023-12-04 14:45:26 -08:00
2024-01-04 18:06:46 -08:00
2023-10-23 15:01:53 -07:00
2023-07-28 14:07:59 -07:00
2023-10-13 11:26:10 +01:00
2023-08-01 15:06:27 -07:00
2022-12-12 15:04:39 -08:00
2022-07-22 12:53:22 +01:00
2023-10-23 08:48:57 +01:00
2023-08-07 08:53:55 +01:00
2023-09-14 16:16:36 +02:00
2023-11-16 22:33:31 +00:00
2023-03-18 12:23:34 +00:00
2022-07-22 12:53:22 +01:00
2024-01-24 16:24:06 -08:00
2023-11-29 14:59:40 -08:00
2023-12-14 16:38:59 +01:00
2023-12-14 17:12:49 -08:00
2023-12-13 16:16:40 -08:00