syzbot

RSP: 002b:00007fffa6f94b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 00007fffa6f94b90 RCX: 00007f548015e799
RDX: 0000000073528428 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fffa6f94917 R09: 0000000000000140
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffa6f94da8 R14: 00007fffa6f94bb0 R15: 00007fffa6f94ba0
 </TASK>
=====================================
WARNING: bad unlock balance detected!
6.15.0-syzkaller-13743-g8630c59e9936 #0 Not tainted
-------------------------------------
syz-executor738/5832 is trying to release lock (event_mutex) at:
[<ffffffff823f5690>] traverse.part.0.constprop.0+0x2c0/0x640 fs/seq_file.c:131
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor738/5832:
 #0: ffff88807dc3c790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182

stack backtrace:
CPU: 0 UID: 0 PID: 5832 Comm: syz-executor738 Not tainted 6.15.0-syzkaller-13743-g8630c59e9936 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_unlock_imbalance_bug kernel/locking/lockdep.c:5301 [inline]
 print_unlock_imbalance_bug+0x11b/0x130 kernel/locking/lockdep.c:5275
 __lock_release kernel/locking/lockdep.c:5540 [inline]
 lock_release+0x242/0x2f0 kernel/locking/lockdep.c:5892
 __mutex_unlock_slowpath+0xa2/0x6a0 kernel/locking/mutex.c:909
 traverse.part.0.constprop.0+0x2c0/0x640 fs/seq_file.c:131
 traverse fs/seq_file.c:98 [inline]
 seq_read_iter+0x932/0x12c0 fs/seq_file.c:195
 seq_read+0x39e/0x4e0 fs/seq_file.c:162
 vfs_read+0x1e1/0xc60 fs/read_write.c:570
 ksys_pread64 fs/read_write.c:763 [inline]
 __do_sys_pread64 fs/read_write.c:771 [inline]
 __se_sys_pread64 fs/read_write.c:768 [inline]
 __x64_sys_pread64+0x1eb/0x250 fs/read_write.c:768
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f548015e799
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa6f94b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 00007fffa6f94b90 RCX: 00007f548015e799
RDX: 0000000073528428 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fffa6f94917 R09: 0000000000000140
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffa6f94da8 R14: 00007fffa6f94bb0 R15: 00007fffa6f94ba0
 </TASK>