[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ 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 '10.128.1.67' (ECDSA) to the list of known hosts. 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 syzkaller login: [ 70.234148][ T8646] [ 70.236507][ T8646] ====================================================== [ 70.243512][ T8646] WARNING: possible circular locking dependency detected [ 70.250512][ T8646] 5.14.0-rc5-syzkaller #0 Not tainted [ 70.255866][ T8646] ------------------------------------------------------ [ 70.262852][ T8646] systemd-udevd/8646 is trying to acquire lock: [ 70.269061][ T8646] ffffffff8c486b88 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 70.277484][ T8646] [ 70.277484][ T8646] but task is already holding lock: [ 70.284826][ T8646] ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 70.294289][ T8646] [ 70.294289][ T8646] which lock already depends on the new lock. [ 70.294289][ T8646] [ 70.304664][ T8646] [ 70.304664][ T8646] the existing dependency chain (in reverse order) is: [ 70.313653][ T8646] [ 70.313653][ T8646] -> #3 (major_names_lock){+.+.}-{3:3}: [ 70.321356][ T8646] __mutex_lock+0x12a/0x10a0 [ 70.326464][ T8646] __register_blkdev+0x2b/0x3e0 [ 70.331824][ T8646] register_mtd_blktrans+0x85/0x3c0 [ 70.337524][ T8646] do_one_initcall+0x103/0x650 [ 70.342787][ T8646] kernel_init_freeable+0x6b8/0x741 [ 70.348486][ T8646] kernel_init+0x1a/0x1d0 [ 70.353318][ T8646] ret_from_fork+0x1f/0x30 [ 70.358240][ T8646] [ 70.358240][ T8646] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 70.365854][ T8646] __mutex_lock+0x12a/0x10a0 [ 70.370944][ T8646] blktrans_open+0x69/0x600 [ 70.375949][ T8646] blkdev_get_whole+0xa1/0x420 [ 70.381216][ T8646] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 70.387262][ T8646] blkdev_open+0x295/0x300 [ 70.392174][ T8646] do_dentry_open+0x4c8/0x11d0 [ 70.397436][ T8646] path_openat+0x1c23/0x27f0 [ 70.402526][ T8646] do_filp_open+0x1aa/0x400 [ 70.407528][ T8646] do_sys_openat2+0x16d/0x420 [ 70.412705][ T8646] __x64_sys_open+0x119/0x1c0 [ 70.417880][ T8646] do_syscall_64+0x35/0xb0 [ 70.422799][ T8646] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 70.429187][ T8646] [ 70.429187][ T8646] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 70.436974][ T8646] __mutex_lock+0x12a/0x10a0 [ 70.442108][ T8646] del_gendisk+0x8b/0x770 [ 70.446938][ T8646] loop_control_ioctl+0x3b5/0x450 [ 70.452465][ T8646] __x64_sys_ioctl+0x193/0x200 [ 70.457731][ T8646] do_syscall_64+0x35/0xb0 [ 70.462644][ T8646] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 70.469034][ T8646] [ 70.469034][ T8646] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 70.476561][ T8646] __lock_acquire+0x2a07/0x54a0 [ 70.481911][ T8646] lock_acquire+0x1ab/0x510 [ 70.486944][ T8646] __mutex_lock+0x12a/0x10a0 [ 70.492044][ T8646] loop_add+0x9c/0x8c0 [ 70.496617][ T8646] loop_probe+0x6a/0x80 [ 70.501311][ T8646] blk_request_module+0x111/0x1d0 [ 70.506856][ T8646] blkdev_get_no_open+0x1d5/0x250 [ 70.512385][ T8646] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 70.518343][ T8646] blkdev_open+0x295/0x300 [ 70.523256][ T8646] do_dentry_open+0x4c8/0x11d0 [ 70.528518][ T8646] path_openat+0x1c23/0x27f0 [ 70.533607][ T8646] do_filp_open+0x1aa/0x400 [ 70.538608][ T8646] do_sys_openat2+0x16d/0x420 [ 70.543785][ T8646] __x64_sys_open+0x119/0x1c0 [ 70.548961][ T8646] do_syscall_64+0x35/0xb0 [ 70.553877][ T8646] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 70.560267][ T8646] [ 70.560267][ T8646] other info that might help us debug this: [ 70.560267][ T8646] [ 70.570465][ T8646] Chain exists of: [ 70.570465][ T8646] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 70.570465][ T8646] [ 70.583465][ T8646] Possible unsafe locking scenario: [ 70.583465][ T8646] [ 70.590887][ T8646] CPU0 CPU1 [ 70.596226][ T8646] ---- ---- [ 70.601580][ T8646] lock(major_names_lock); [ 70.606064][ T8646] lock(mtd_table_mutex); [ 70.612980][ T8646] lock(major_names_lock); [ 70.619971][ T8646] lock(loop_ctl_mutex); [ 70.624284][ T8646] [ 70.624284][ T8646] *** DEADLOCK *** [ 70.624284][ T8646] [ 70.632397][ T8646] 1 lock held by systemd-udevd/8646: [ 70.637653][ T8646] #0: ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 70.647546][ T8646] [ 70.647546][ T8646] stack backtrace: [ 70.653417][ T8646] CPU: 0 PID: 8646 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 [ 70.661978][ T8646] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.672019][ T8646] Call Trace: [ 70.675284][ T8646] dump_stack_lvl+0xcd/0x134 [ 70.679859][ T8646] check_noncircular+0x25f/0x2e0 [ 70.684775][ T8646] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 70.690731][ T8646] ? print_circular_bug+0x1e0/0x1e0 [ 70.695906][ T8646] ? lock_chain_count+0x20/0x20 [ 70.700748][ T8646] ? lockdep_lock+0xc6/0x200 [ 70.705329][ T8646] ? call_rcu_zapped+0xb0/0xb0 [ 70.710070][ T8646] __lock_acquire+0x2a07/0x54a0 [ 70.714908][ T8646] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 70.720871][ T8646] lock_acquire+0x1ab/0x510 [ 70.725363][ T8646] ? loop_add+0x9c/0x8c0 [ 70.729582][ T8646] ? lock_release+0x720/0x720 [ 70.734234][ T8646] ? path_openat+0x1c23/0x27f0 [ 70.738972][ T8646] ? do_filp_open+0x1aa/0x400 [ 70.743624][ T8646] ? do_sys_openat2+0x16d/0x420 [ 70.748466][ T8646] ? __x64_sys_open+0x119/0x1c0 [ 70.753299][ T8646] __mutex_lock+0x12a/0x10a0 [ 70.757870][ T8646] ? loop_add+0x9c/0x8c0 [ 70.762089][ T8646] ? loop_add+0x9c/0x8c0 [ 70.766307][ T8646] ? mutex_lock_io_nested+0xf00/0xf00 [ 70.771660][ T8646] ? rcu_read_lock_sched_held+0x3a/0x70 [ 70.777189][ T8646] loop_add+0x9c/0x8c0 [ 70.781234][ T8646] ? find_inode_fast+0x16f/0x220 [ 70.786150][ T8646] loop_probe+0x6a/0x80 [ 70.790282][ T8646] ? loop_add+0x8c0/0x8c0 [ 70.794588][ T8646] blk_request_module+0x111/0x1d0 [ 70.799606][ T8646] blkdev_get_no_open+0x1d5/0x250 [ 70.804610][ T8646] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 70.810050][ T8646] ? devcgroup_check_permission+0x1bb/0x410 [ 70.816021][ T8646] blkdev_open+0x295/0x300 [ 70.820426][ T8646] do_dentry_open+0x4c8/0x11d0 [ 70.825176][ T8646] ? blkdev_get_by_dev+0x80/0x80 [ 70.830095][ T8646] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 70.836351][ T8646] ? may_open+0x1f6/0x420 [ 70.840662][ T8646] path_openat+0x1c23/0x27f0 [ 70.845233][ T8646] ? path_lookupat+0x860/0x860 [ 70.849975][ T8646] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 70.855950][ T8646] do_filp_open+0x1aa/0x400 [ 70.860435][ T8646] ? may_open_dev+0xf0/0xf0 [ 70.864917][ T8646] ? rwlock_bug.part.0+0x90/0x90 [ 70.869835][ T8646] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 70.876091][ T8646] ? _find_next_bit+0x1e3/0x260 [ 70.880923][ T8646] ? _raw_spin_unlock+0x24/0x40 [ 70.885755][ T8646] ? alloc_fd+0x2f0/0x670 [ 70.890064][ T8646] do_sys_openat2+0x16d/0x420 [ 70.894727][ T8646] ? build_open_flags+0x6f0/0x6f0 [ 70.899768][ T8646] ? __context_tracking_exit+0xb8/0xe0 [ 70.905210][ T8646] __x64_sys_open+0x119/0x1c0 [ 70.909870][ T8646] ? do_sys_open+0x140/0x140 [ 70.914530][ T8646] ? __secure_computing+0x104/0x360 [ 70.919711][ T8646] do_syscall_64+0x35/0xb0 [ 70.924111][ T8646] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 70.929981][ T8646] RIP: 0033:0x7fc93fb8a840 [ 70.934378][ T8646] 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 [ 70.953965][ T8646] RSP: 002b:00007ffca64ad3e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 70.962357][ T8646] RAX: ffffffffffffffda RBX: 00005556bf474e10 RCX: 00007fc93fb8a840 [ 70.970307][ T8646] RDX: 00005556bf3f9fe3 RSI: 00000000000a0800 RDI: 00005556bf473590 [ 70.978255][ T8646] RBP: 00007ffca64ad560 R08: 00005556bf3f9670 R09: 0000000000000010 executing program executing program executing program [ 70.986293][ T8646] R10: 00005556bf3f9d0c R11: 0000000000000246 R12: 00007ffca64ad4b0 [ 70.994242][ T8646] R13: 00005556bf474f10 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 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 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