======================================================
WARNING: possible circular locking dependency detected
5.16.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/9867 is trying to acquire lock:
ffff88802c9c8e78 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:86 [inline]
ffff88802c9c8e78 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_fill+0xaa7/0x1100 net/unix/diag.c:154
but task is already holding lock:
ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:68 [inline]
ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_fill+0x9bb/0x1100 net/unix/diag.c:154
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (rlock-AF_UNIX){+.+.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
skb_queue_tail+0x21/0x140 net/core/skbuff.c:3319
unix_dgram_sendmsg+0xf60/0x1950 net/unix/af_unix.c:1939
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
io_send+0x349/0x4d0 fs/io_uring.c:4883
io_issue_sqe+0x3814/0x7060 fs/io_uring.c:6694
__io_queue_sqe fs/io_uring.c:7018 [inline]
io_queue_sqe fs/io_uring.c:7060 [inline]
io_submit_sqe fs/io_uring.c:7263 [inline]
io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7369
__do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10072
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #0 (&u->lock/1){+.+.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]
validate_chain kernel/locking/lockdep.c:3801 [inline]
__lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
_raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:368
sk_diag_dump_icons net/unix/diag.c:86 [inline]
sk_diag_fill+0xaa7/0x1100 net/unix/diag.c:154
sk_diag_dump net/unix/diag.c:192 [inline]
unix_diag_dump+0x399/0x590 net/unix/diag.c:220
netlink_dump+0x4b0/0xb60 net/netlink/af_netlink.c:2270
__netlink_dump_start+0x642/0x900 net/netlink/af_netlink.c:2375
netlink_dump_start include/linux/netlink.h:254 [inline]
unix_diag_handler_dump+0x411/0x7d0 net/unix/diag.c:319
__sock_diag_cmd net/core/sock_diag.c:234 [inline]
sock_diag_rcv_msg+0x31a/0x440 net/core/sock_diag.c:265
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:276
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
sock_write_iter+0x289/0x3c0 net/socket.c:1057
call_write_iter include/linux/fs.h:2162 [inline]
do_iter_readv_writev+0x472/0x750 fs/read_write.c:725
do_iter_write+0x188/0x710 fs/read_write.c:851
vfs_writev+0x1aa/0x630 fs/read_write.c:924
do_writev+0x27f/0x300 fs/read_write.c:967
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(rlock-AF_UNIX);
lock(&u->lock/1);
lock(rlock-AF_UNIX);
lock(&u->lock/1);
*** DEADLOCK ***
5 locks held by syz-executor.2/9867:
#0: ffffffff8d317dc8 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x17/0x40 net/core/sock_diag.c:275
#1: ffffffff8d317f48 (sock_diag_table_mutex){+.+.}-{3:3}, at: __sock_diag_cmd net/core/sock_diag.c:229 [inline]
#1: ffffffff8d317f48 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0x19b/0x440 net/core/sock_diag.c:265
#2: ffff88801eff8680 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xb0/0xb60 net/netlink/af_netlink.c:2225
#3: ffffffff8d4a7438 (unix_table_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#3: ffffffff8d4a7438 (unix_table_lock){+.+.}-{2:2}, at: unix_diag_dump+0x119/0x590 net/unix/diag.c:206
#4: ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#4: ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:68 [inline]
#4: ffff88807b8ec1d8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_fill+0x9bb/0x1100 net/unix/diag.c:154
stack backtrace:
CPU: 1 PID: 9867 Comm: syz-executor.2 Not tainted 5.16.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2143
check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]
validate_chain kernel/locking/lockdep.c:3801 [inline]
__lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
_raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:368
sk_diag_dump_icons net/unix/diag.c:86 [inline]
sk_diag_fill+0xaa7/0x1100 net/unix/diag.c:154
sk_diag_dump net/unix/diag.c:192 [inline]
unix_diag_dump+0x399/0x590 net/unix/diag.c:220
netlink_dump+0x4b0/0xb60 net/netlink/af_netlink.c:2270
__netlink_dump_start+0x642/0x900 net/netlink/af_netlink.c:2375
netlink_dump_start include/linux/netlink.h:254 [inline]
unix_diag_handler_dump+0x411/0x7d0 net/unix/diag.c:319
__sock_diag_cmd net/core/sock_diag.c:234 [inline]
sock_diag_rcv_msg+0x31a/0x440 net/core/sock_diag.c:265
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496
sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:276
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
sock_write_iter+0x289/0x3c0 net/socket.c:1057
call_write_iter include/linux/fs.h:2162 [inline]
do_iter_readv_writev+0x472/0x750 fs/read_write.c:725
do_iter_write+0x188/0x710 fs/read_write.c:851
vfs_writev+0x1aa/0x630 fs/read_write.c:924
do_writev+0x27f/0x300 fs/read_write.c:967
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f39f05f5e99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007f39eef6b168 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f39f0708f60 RCX: 00007f39f05f5e99
RDX: 0000000000000001 RSI: 00000000200000c0 RDI: 0000000000000006
RBP: 00007f39f064fff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe91f1e3ef R14: 00007f39eef6b300 R15: 0000000000022000
</TASK>