====================================================== WARNING: possible circular locking dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted ------------------------------------------------------ syz-executor.2/6978 is trying to acquire lock: ffff88802fa20c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_llseek+0x7e/0x2a0 fs/kernfs/file.c:867 but task is already holding lock: ffff88805d2e5688 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_inode_lock fs/overlayfs/overlayfs.h:649 [inline] ffff88805d2e5688 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_llseek+0x26b/0x470 fs/overlayfs/file.c:214 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ovl_i_lock_key[depth]){+.+.}-{3:3}: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:654 [inline] ovl_nlink_start+0xdc/0x390 fs/overlayfs/util.c:1162 ovl_do_remove+0x1fa/0xd90 fs/overlayfs/dir.c:893 vfs_rmdir+0x367/0x4c0 fs/namei.c:4209 do_rmdir+0x3b5/0x580 fs/namei.c:4268 __do_sys_rmdir fs/namei.c:4287 [inline] __se_sys_rmdir fs/namei.c:4285 [inline] __x64_sys_rmdir+0x49/0x60 fs/namei.c:4285 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 -> #1 (&ovl_i_mutex_dir_key[depth]#2){++++}-{3:3}: lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:803 [inline] lookup_slow+0x45/0x70 fs/namei.c:1708 walk_component+0x2e1/0x410 fs/namei.c:2004 lookup_last fs/namei.c:2461 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2485 filename_lookup+0x256/0x610 fs/namei.c:2514 kern_path+0x35/0x50 fs/namei.c:2622 lookup_bdev+0xc5/0x290 block/bdev.c:1072 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 -> #0 (&of->mutex){+.+.}-{3:3}: 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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 kernfs_fop_llseek+0x7e/0x2a0 fs/kernfs/file.c:867 ovl_llseek+0x314/0x470 fs/overlayfs/file.c:218 vfs_llseek fs/read_write.c:289 [inline] ksys_lseek fs/read_write.c:302 [inline] __do_sys_lseek fs/read_write.c:313 [inline] __se_sys_lseek fs/read_write.c:311 [inline] __x64_sys_lseek+0x153/0x1e0 fs/read_write.c:311 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 other info that might help us debug this: Chain exists of: &of->mutex --> &ovl_i_mutex_dir_key[depth]#2 --> &ovl_i_lock_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_lock_key[depth]); lock(&ovl_i_mutex_dir_key[depth]#2); lock(&ovl_i_lock_key[depth]); lock(&of->mutex); *** DEADLOCK *** 2 locks held by syz-executor.2/6978: #0: ffff88802b656848 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x259/0x320 fs/file.c:1191 #1: ffff88805d2e5688 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_inode_lock fs/overlayfs/overlayfs.h:649 [inline] #1: ffff88805d2e5688 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_llseek+0x26b/0x470 fs/overlayfs/file.c:214 stack backtrace: CPU: 0 PID: 6978 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __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+0x1e4/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 kernfs_fop_llseek+0x7e/0x2a0 fs/kernfs/file.c:867 ovl_llseek+0x314/0x470 fs/overlayfs/file.c:218 vfs_llseek fs/read_write.c:289 [inline] ksys_lseek fs/read_write.c:302 [inline] __do_sys_lseek fs/read_write.c:313 [inline] __se_sys_lseek fs/read_write.c:311 [inline] __x64_sys_lseek+0x153/0x1e0 fs/read_write.c:311 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f3432c7de69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34339310c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f3432dabf80 RCX: 00007f3432c7de69 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f3432cca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f3432dabf80 R15: 00007fffae383818