[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.232' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 61.935765][ T8431] [ 61.938108][ T8431] ====================================================== [ 61.945100][ T8431] WARNING: possible circular locking dependency detected [ 61.952089][ T8431] 5.13.0-rc6-syzkaller #0 Not tainted [ 61.957455][ T8431] ------------------------------------------------------ [ 61.964446][ T8431] systemd-udevd/8431 is trying to acquire lock: [ 61.970653][ T8431] ffffffff8ca6dd68 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_probe+0xc7/0x150 [ 61.979247][ T8431] [ 61.979247][ T8431] but task is already holding lock: [ 61.986629][ T8431] ffffffff8c7e02e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 61.996127][ T8431] [ 61.996127][ T8431] which lock already depends on the new lock. [ 61.996127][ T8431] [ 62.006511][ T8431] [ 62.006511][ T8431] the existing dependency chain (in reverse order) is: [ 62.015498][ T8431] [ 62.015498][ T8431] -> #3 (major_names_lock){+.+.}-{3:3}: [ 62.023248][ T8431] __mutex_lock+0x139/0x10c0 [ 62.028463][ T8431] __register_blkdev+0x2b/0x3e0 [ 62.033823][ T8431] register_mtd_blktrans+0x85/0x3c0 [ 62.039524][ T8431] do_one_initcall+0x103/0x650 [ 62.044788][ T8431] kernel_init_freeable+0x6c4/0x74d [ 62.050487][ T8431] kernel_init+0xd/0x1b8 [ 62.055225][ T8431] ret_from_fork+0x1f/0x30 [ 62.060217][ T8431] [ 62.060217][ T8431] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 62.067845][ T8431] __mutex_lock+0x139/0x10c0 [ 62.072953][ T8431] blktrans_open+0x69/0x600 [ 62.077969][ T8431] __blkdev_get+0x182/0xa30 [ 62.082974][ T8431] blkdev_get_by_dev+0x200/0x660 [ 62.088412][ T8431] blkdev_open+0x154/0x2b0 [ 62.093370][ T8431] do_dentry_open+0x4b9/0x11b0 [ 62.098648][ T8431] path_openat+0x1c0e/0x27e0 [ 62.103739][ T8431] do_filp_open+0x190/0x3d0 [ 62.108746][ T8431] do_sys_openat2+0x16d/0x420 [ 62.113935][ T8431] __x64_sys_open+0x119/0x1c0 [ 62.119104][ T8431] do_syscall_64+0x3a/0xb0 [ 62.124014][ T8431] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 62.130406][ T8431] [ 62.130406][ T8431] -> #1 (&bdev->bd_mutex){+.+.}-{3:3}: [ 62.138021][ T8431] __mutex_lock+0x139/0x10c0 [ 62.143110][ T8431] del_gendisk+0x24b/0xa00 [ 62.148028][ T8431] loop_control_ioctl+0x3e7/0x4c0 [ 62.153674][ T8431] __x64_sys_ioctl+0x193/0x200 [ 62.158935][ T8431] do_syscall_64+0x3a/0xb0 [ 62.163851][ T8431] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 62.170239][ T8431] [ 62.170239][ T8431] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 62.177769][ T8431] __lock_acquire+0x2a17/0x5230 [ 62.183126][ T8431] lock_acquire+0x1ab/0x740 [ 62.188489][ T8431] __mutex_lock+0x139/0x10c0 [ 62.193583][ T8431] loop_probe+0xc7/0x150 [ 62.198333][ T8431] blk_request_module+0x111/0x1d0 [ 62.203865][ T8431] blkdev_get_no_open+0x1d8/0x250 [ 62.209388][ T8431] blkdev_get_by_dev+0x76/0x660 [ 62.214756][ T8431] blkdev_open+0x154/0x2b0 [ 62.219669][ T8431] do_dentry_open+0x4b9/0x11b0 [ 62.224933][ T8431] path_openat+0x1c0e/0x27e0 [ 62.230022][ T8431] do_filp_open+0x190/0x3d0 [ 62.235032][ T8431] do_sys_openat2+0x16d/0x420 [ 62.240210][ T8431] __x64_sys_open+0x119/0x1c0 [ 62.245384][ T8431] do_syscall_64+0x3a/0xb0 [ 62.250326][ T8431] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 62.256748][ T8431] [ 62.256748][ T8431] other info that might help us debug this: [ 62.256748][ T8431] [ 62.266967][ T8431] Chain exists of: [ 62.266967][ T8431] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 62.266967][ T8431] [ 62.279977][ T8431] Possible unsafe locking scenario: [ 62.279977][ T8431] [ 62.287403][ T8431] CPU0 CPU1 [ 62.292745][ T8431] ---- ---- [ 62.298100][ T8431] lock(major_names_lock); [ 62.302596][ T8431] lock(mtd_table_mutex); [ 62.309524][ T8431] lock(major_names_lock); [ 62.316519][ T8431] lock(loop_ctl_mutex); [ 62.321104][ T8431] [ 62.321104][ T8431] *** DEADLOCK *** [ 62.321104][ T8431] [ 62.329224][ T8431] 1 lock held by systemd-udevd/8431: [ 62.334483][ T8431] #0: ffffffff8c7e02e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 62.344487][ T8431] [ 62.344487][ T8431] stack backtrace: [ 62.350368][ T8431] CPU: 0 PID: 8431 Comm: systemd-udevd Not tainted 5.13.0-rc6-syzkaller #0 [ 62.358930][ T8431] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.368961][ T8431] Call Trace: [ 62.372237][ T8431] dump_stack+0x141/0x1d7 [ 62.376546][ T8431] check_noncircular+0x25f/0x2e0 [ 62.381462][ T8431] ? print_circular_bug+0x1e0/0x1e0 [ 62.386637][ T8431] ? mark_lock+0xef/0x17b0 [ 62.391046][ T8431] ? lockdep_lock+0xc6/0x200 [ 62.395615][ T8431] ? call_rcu_zapped+0xb0/0xb0 [ 62.400355][ T8431] ? tomoyo_check_open_permission+0x172/0x380 [ 62.406427][ T8431] ? security_file_open+0x52/0x4f0 [ 62.411520][ T8431] __lock_acquire+0x2a17/0x5230 [ 62.416382][ T8431] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.422350][ T8431] lock_acquire+0x1ab/0x740 [ 62.426886][ T8431] ? loop_probe+0xc7/0x150 [ 62.431315][ T8431] ? lock_release+0x720/0x720 [ 62.435991][ T8431] __mutex_lock+0x139/0x10c0 [ 62.440559][ T8431] ? loop_probe+0xc7/0x150 [ 62.444951][ T8431] ? loop_probe+0xc7/0x150 [ 62.449347][ T8431] ? mutex_lock_io_nested+0xf20/0xf20 [ 62.454697][ T8431] ? __mutex_lock+0x5d5/0x10c0 [ 62.459443][ T8431] ? blk_request_module+0x25/0x1d0 [ 62.464546][ T8431] ? find_held_lock+0x2d/0x110 [ 62.469291][ T8431] ? mutex_lock_io_nested+0xf20/0xf20 [ 62.474656][ T8431] ? ilookup+0xb3/0x230 [ 62.478804][ T8431] loop_probe+0xc7/0x150 [ 62.483024][ T8431] ? loop_control_ioctl+0x4c0/0x4c0 [ 62.488201][ T8431] ? find_inode_fast+0x16f/0x220 [ 62.493123][ T8431] ? do_raw_spin_unlock+0x171/0x230 [ 62.498334][ T8431] ? loop_control_ioctl+0x4c0/0x4c0 [ 62.504433][ T8431] blk_request_module+0x111/0x1d0 [ 62.509442][ T8431] blkdev_get_no_open+0x1d8/0x250 [ 62.514458][ T8431] blkdev_get_by_dev+0x76/0x660 [ 62.519287][ T8431] blkdev_open+0x154/0x2b0 [ 62.523683][ T8431] do_dentry_open+0x4b9/0x11b0 [ 62.528445][ T8431] ? blkdev_get_by_dev+0x660/0x660 [ 62.533588][ T8431] ? may_open+0x1f6/0x420 [ 62.538017][ T8431] path_openat+0x1c0e/0x27e0 [ 62.542622][ T8431] ? path_lookupat+0x850/0x850 [ 62.547375][ T8431] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 62.553342][ T8431] do_filp_open+0x190/0x3d0 [ 62.557834][ T8431] ? may_open_dev+0xf0/0xf0 [ 62.562321][ T8431] ? do_raw_spin_lock+0x120/0x2b0 [ 62.567389][ T8431] ? rwlock_bug.part.0+0x90/0x90 [ 62.572322][ T8431] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 62.578556][ T8431] ? _find_next_bit+0x1e3/0x260 [ 62.583446][ T8431] ? _raw_spin_unlock+0x24/0x40 [ 62.588277][ T8431] ? alloc_fd+0x2e6/0x660 [ 62.592591][ T8431] do_sys_openat2+0x16d/0x420 [ 62.597249][ T8431] ? build_open_flags+0x6f0/0x6f0 [ 62.602298][ T8431] ? __context_tracking_exit+0xb8/0xe0 [ 62.608101][ T8431] __x64_sys_open+0x119/0x1c0 [ 62.613443][ T8431] ? do_sys_open+0x140/0x140 [ 62.618020][ T8431] ? __secure_computing+0x104/0x360 [ 62.623225][ T8431] do_syscall_64+0x3a/0xb0 [ 62.627637][ T8431] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 62.633528][ T8431] RIP: 0033:0x7f1b0bd1e840 [ 62.637952][ T8431] Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 [ 62.657546][ T8431] RSP: 002b:00007ffe1a06b7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 62.665962][ T8431] RAX: ffffffffffffffda RBX: 000056337a287ee0 RCX: 00007f1b0bd1e840 [ 62.673918][ T8431] RDX: 0000563379355fe3 RSI: 00000000000a0800 RDI: 000056337a29b1b0 executing program executing program executing program executing program executing program [ 62.681870][ T8431] RBP: 00007ffe1a06b920 R08: 0000563379355670 R09: 0000000000000010 [ 62.689826][ T8431] R10: 0000563379355d0c R11: 0000000000000246 R12: 00007ffe1a06b870 [ 62.697873][ T8431] R13: 000056337a29ce10 R14: 0000000000000003 R15: 000000000000000e executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program