===================================== WARNING: bad unlock balance detected! 5.5.0-rc7-syzkaller #0 Not tainted ------------------------------------- syz-executor.5/11435 is trying to release lock (&ovl_i_lock_key[depth]) at: [] ovl_inode_unlock fs/overlayfs/overlayfs.h:319 [inline] [] ovl_llseek+0x233/0x360 fs/overlayfs/file.c:182 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor.5/11435: #0: ffff888095689d60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa3/0xc0 fs/file.c:801 stack backtrace: CPU: 0 PID: 11435 Comm: syz-executor.5 Not tainted 5.5.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 print_unlock_imbalance_bug.cold.53+0x114/0x123 kernel/locking/lockdep.c:4007 __lock_release kernel/locking/lockdep.c:4241 [inline] lock_release+0x60e/0x910 kernel/locking/lockdep.c:4502 __mutex_unlock_slowpath+0x86/0x690 kernel/locking/mutex.c:1228 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:740 ovl_inode_unlock fs/overlayfs/overlayfs.h:319 [inline] ovl_llseek+0x233/0x360 fs/overlayfs/file.c:182 vfs_llseek fs/read_write.c:300 [inline] ksys_lseek+0xc8/0x150 fs/read_write.c:313 __do_sys_lseek fs/read_write.c:324 [inline] __se_sys_lseek fs/read_write.c:322 [inline] __x64_sys_lseek+0x6e/0xb0 fs/read_write.c:322 do_syscall_64+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f8664f16c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f8664f176d4 RCX: 000000000045c449 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000718 R14: 00000000004c9a15 R15: 000000000076c06c