Kuniyuki Iwashima
b29dcdd058
af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().
...
commit 1971d13ffa84a551d29a81fdf5b5ec5be166ac83 upstream.
syzbot reported a lockdep splat regarding unix_gc_lock and
unix_state_lock().
One is called from recvmsg() for a connected socket, and another
is called from GC for TCP_LISTEN socket.
So, the splat is false-positive.
Let's add a dedicated lock class for the latter to suppress the splat.
Note that this change is not necessary for net-next.git as the issue
is only applied to the old GC impl.
[0]:
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Not tainted
-----------------------------------------------------
kworker/u8:1/11 is trying to acquire lock:
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807cea4e70 (&u->lock){+.+.}-{2:2}, at: __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
but task is already holding lock:
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (unix_gc_lock){+.+.}-{2:2}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
unix_notinflight+0x13d/0x390 net/unix/garbage.c:140
unix_detach_fds net/unix/af_unix.c:1819 [inline]
unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876
skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188
skb_release_all net/core/skbuff.c:1200 [inline]
__kfree_skb net/core/skbuff.c:1216 [inline]
kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1252
kfree_skb include/linux/skbuff.h:1262 [inline]
manage_oob net/unix/af_unix.c:2672 [inline]
unix_stream_read_generic+0x1125/0x2700 net/unix/af_unix.c:2749
unix_stream_splice_read+0x239/0x320 net/unix/af_unix.c:2981
do_splice_read fs/splice.c:985 [inline]
splice_file_to_pipe+0x299/0x500 fs/splice.c:1295
do_splice+0xf2d/0x1880 fs/splice.c:1379
__do_splice fs/splice.c:1436 [inline]
__do_sys_splice fs/splice.c:1652 [inline]
__se_sys_splice+0x331/0x4a0 fs/splice.c:1634
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&u->lock){+.+.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__unix_gc+0x40e/0xf70 net/unix/garbage.c:302
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(unix_gc_lock);
lock(&u->lock);
lock(unix_gc_lock);
lock(&u->lock);
*** DEADLOCK ***
3 locks held by kworker/u8:1/11:
#0 : ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0 : ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335
#1 : ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1 : ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335
#2 : ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2 : ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261
stack backtrace:
CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__unix_gc+0x40e/0xf70 net/unix/garbage.c:302
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Fixes: 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()")
Reported-and-tested-by: syzbot+fa379358c28cc87cc307@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa379358c28cc87cc307
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240424170443.9832-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-17 11:42:43 +02:00
..
2019-07-03 13:14:42 +02:00
2024-01-25 14:33:34 -08:00
2021-06-10 13:24:06 +02:00
2018-06-28 10:40:47 -07:00
2023-08-16 18:13:01 +02:00
2024-01-15 18:23:44 +01:00
2023-08-11 11:45:03 +02:00
2019-03-23 20:09:51 +01:00
2022-01-05 12:34:58 +01:00
2022-05-18 09:42:48 +02:00
2020-06-03 08:19:15 +02:00
2024-05-02 16:17:08 +02:00
2018-07-13 12:18:18 -04:00
2018-08-03 12:46:20 -07:00
2024-05-17 11:42:43 +02:00
2018-08-07 12:39:13 -07:00
2017-11-02 11:10:55 +01:00
2022-04-15 14:15:01 +02:00
2017-11-02 11:10:55 +01:00
2022-04-27 13:39:45 +02:00
2018-04-19 16:11:11 -04:00
2022-02-23 11:58:39 +01:00
2021-12-14 10:18:05 +01:00
2023-08-30 16:31:54 +02:00
2022-09-05 10:26:30 +02:00
2023-08-16 18:13:00 +02:00
2022-03-02 11:38:12 +01:00
2018-04-02 20:16:17 +02:00
2017-11-02 11:10:55 +01:00
2018-07-27 13:17:50 -07:00
2018-10-10 10:19:10 -07:00
2020-11-10 12:36:02 +01:00
2017-11-02 11:10:55 +01:00
2018-03-05 12:52:45 -05:00
2022-02-16 12:51:46 +01:00
2024-01-15 18:23:44 +01:00
2023-10-10 21:44:57 +02:00
2024-04-13 12:50:14 +02:00
2022-07-12 16:29:00 +02:00
2018-02-28 11:43:28 -05:00
2018-05-28 22:59:54 -04:00
2017-11-01 11:50:43 +09:00
2020-03-18 07:14:14 +01:00
2017-11-02 11:10:55 +01:00
2022-04-20 09:12:48 +02:00
2018-07-20 10:14:41 +02:00
2017-11-02 11:10:55 +01:00
2019-12-05 09:19:45 +01:00
2019-11-10 11:27:54 +01:00
2017-11-02 11:10:55 +01:00
2018-08-11 12:37:10 -07:00
2023-12-13 17:42:20 +01:00
2017-11-02 11:10:55 +01:00
2018-02-27 14:46:26 -05:00
2017-11-02 11:10:55 +01:00
2017-11-02 11:10:55 +01:00
2017-12-11 14:10:06 -05:00
2017-11-02 11:10:55 +01:00
2021-03-04 09:39:59 +01:00
2018-06-15 14:04:00 +02:00
2022-10-26 13:19:42 +02:00
2022-06-14 16:59:14 +02:00
2018-04-22 21:12:00 -04:00
2017-08-07 11:39:22 -07:00
2018-06-26 11:33:04 +09:00
2024-04-13 12:50:12 +02:00
2020-07-22 09:32:00 +02:00
2019-04-27 09:36:33 +02:00
2022-06-06 08:24:20 +02:00
2022-07-29 17:10:31 +02:00
2018-06-05 10:45:24 -04:00
2019-02-23 09:07:24 +01:00
2022-02-08 18:23:09 +01:00
2021-08-12 13:19:39 +02:00
2023-05-30 12:42:10 +01:00
2019-01-31 08:14:32 +01:00
2024-05-02 16:17:08 +02:00
2020-08-19 08:14:56 +02:00
2023-06-09 10:23:54 +02:00
2017-11-02 11:10:55 +01:00
2017-11-02 11:10:55 +01:00
2019-07-10 09:53:46 +02:00
2023-08-11 11:45:31 +02:00
2020-02-11 04:34:14 -08:00
2018-03-27 09:51:23 +02:00
2019-02-06 17:30:06 +01:00
2018-07-11 23:10:19 -07:00
2017-11-02 11:10:55 +01:00
2017-11-02 11:10:55 +01:00
2017-10-25 12:06:25 +09:00
2019-11-06 13:06:23 +01:00
2024-02-23 08:12:41 +01:00
2021-11-26 11:36:16 +01:00
2023-09-23 10:48:01 +02:00
2018-06-18 22:40:32 +02:00
2017-11-02 11:10:55 +01:00
2023-01-18 11:30:36 +01:00
2017-11-02 11:10:55 +01:00
2017-11-02 11:10:55 +01:00
2023-06-21 15:39:59 +02:00
2018-05-28 22:59:54 -04:00
2021-06-30 08:48:18 -04:00
2017-11-02 11:10:55 +01:00
2018-08-01 09:52:30 -07:00
2018-09-29 11:48:26 -07:00
2019-05-02 09:58:57 +02:00
2018-04-07 22:32:31 -04:00
2021-12-01 09:27:42 +01:00
2017-11-08 16:12:33 +09:00
2017-11-02 11:10:55 +01:00
2018-05-24 18:36:15 -07:00
2018-05-16 07:23:35 +02:00
2020-02-01 09:37:06 +00:00
2023-08-11 11:45:19 +02:00
2017-11-02 11:10:55 +01:00
2022-11-10 17:46:54 +01:00
2021-08-26 08:36:38 -04:00
2017-11-02 11:10:55 +01:00
2018-05-16 07:23:35 +02:00
2017-11-02 11:10:55 +01:00
2021-04-14 08:22:34 +02:00
2018-08-28 11:11:47 +02:00
2020-01-27 14:51:18 +01:00
2018-05-16 07:23:35 +02:00
2018-05-29 10:12:45 -04:00
2018-03-13 18:37:02 +02:00
2021-03-30 14:37:03 +02:00
2022-01-27 09:04:33 +01:00
2023-05-17 11:13:11 +02:00
2022-06-06 08:24:20 +02:00
2018-06-22 13:43:27 +09:00
2018-07-31 09:22:48 +02:00
2018-06-22 13:43:27 +09:00
2018-04-11 10:33:46 -04:00
2018-06-30 20:42:25 +09:00
2019-09-21 07:16:43 +02:00
2024-04-13 12:50:12 +02:00
2018-03-01 21:21:36 -05:00
2017-11-02 11:10:55 +01:00
2018-06-06 14:07:53 -04:00
2018-05-03 13:46:47 -04:00
2018-02-21 15:06:05 -05:00
2023-10-25 11:16:46 +02:00
2018-05-08 00:02:41 -04:00
2020-12-08 10:18:52 +01:00
2018-07-07 10:58:49 +09:00
2017-11-02 11:10:55 +01:00
2017-08-29 15:16:52 -07:00
2018-06-26 11:33:04 +09:00
2023-04-26 11:21:52 +02:00
2023-04-26 11:21:52 +02:00
2018-04-17 13:53:13 -04:00
2018-01-24 19:13:45 -05:00
2017-11-02 11:10:55 +01:00
2017-11-02 11:10:55 +01:00
2019-05-04 09:20:12 +02:00
2018-08-10 16:12:20 +02:00
2022-04-15 14:15:07 +02:00