===================================== WARNING: bad unlock balance detected! 5.6.0-rc3-next-20200228-syzkaller #0 Not tainted ------------------------------------- syz-executor166/9935 is trying to release lock (&ovl_i_lock_key[depth]) at: [] ovl_inode_unlock fs/overlayfs/overlayfs.h:327 [inline] [] ovl_llseek+0x250/0x350 fs/overlayfs/file.c:193 but there are no more locks to release! other info that might help us debug this: 1 lock held by syz-executor166/9935: #0: ffff88809a5221a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 stack backtrace: CPU: 1 PID: 9935 Comm: syz-executor166 Not tainted 5.6.0-rc3-next-20200228-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+0x188/0x20d lib/dump_stack.c:118 __lock_release kernel/locking/lockdep.c:4477 [inline] lock_release+0x586/0x7c0 kernel/locking/lockdep.c:4738 __mutex_unlock_slowpath+0x81/0x660 kernel/locking/mutex.c:1228 ovl_inode_unlock fs/overlayfs/overlayfs.h:327 [inline] ovl_llseek+0x250/0x350 fs/overlayfs/file.c:193 vfs_llseek fs/read_write.c:300 [inline] ksys_lseek+0x10b/0x1a0 fs/read_write.c:313 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4459b9 Code: e8 bc b7 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00