Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.20' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 57.275417][ T8404] [ 57.277943][ T8404] ====================================================== [ 57.285027][ T8404] WARNING: possible circular locking dependency detected [ 57.292213][ T8404] 5.13.0-rc7-syzkaller #0 Not tainted [ 57.297647][ T8404] ------------------------------------------------------ [ 57.304637][ T8404] systemd-udevd/8404 is trying to acquire lock: [ 57.310851][ T8404] ffffffff8ca6de28 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_probe+0xc7/0x150 [ 57.319461][ T8404] [ 57.319461][ T8404] but task is already holding lock: [ 57.326886][ T8404] ffffffff8c7e0368 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 57.336432][ T8404] [ 57.336432][ T8404] which lock already depends on the new lock. [ 57.336432][ T8404] [ 57.346911][ T8404] [ 57.346911][ T8404] the existing dependency chain (in reverse order) is: [ 57.355897][ T8404] [ 57.355897][ T8404] -> #3 (major_names_lock){+.+.}-{3:3}: [ 57.363601][ T8404] __mutex_lock+0x139/0x10c0 [ 57.368702][ T8404] __register_blkdev+0x2b/0x3e0 [ 57.374055][ T8404] register_mtd_blktrans+0x85/0x3c0 [ 57.379757][ T8404] do_one_initcall+0x103/0x650 [ 57.385023][ T8404] kernel_init_freeable+0x6c4/0x74d [ 57.390726][ T8404] kernel_init+0xd/0x1b8 [ 57.395482][ T8404] ret_from_fork+0x1f/0x30 [ 57.400410][ T8404] [ 57.400410][ T8404] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 57.408028][ T8404] __mutex_lock+0x139/0x10c0 [ 57.413209][ T8404] blktrans_open+0x69/0x600 [ 57.418434][ T8404] __blkdev_get+0x182/0xa30 [ 57.423619][ T8404] blkdev_get_by_dev+0x200/0x660 [ 57.429060][ T8404] blkdev_open+0x154/0x2b0 [ 57.433975][ T8404] do_dentry_open+0x4b9/0x11b0 [ 57.439241][ T8404] path_openat+0x1c0e/0x27e0 [ 57.444335][ T8404] do_filp_open+0x190/0x3d0 [ 57.449339][ T8404] do_sys_openat2+0x16d/0x420 [ 57.454513][ T8404] __x64_sys_open+0x119/0x1c0 [ 57.459692][ T8404] do_syscall_64+0x3a/0xb0 [ 57.464608][ T8404] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.471088][ T8404] [ 57.471088][ T8404] -> #1 (&bdev->bd_mutex){+.+.}-{3:3}: [ 57.478706][ T8404] __mutex_lock+0x139/0x10c0 [ 57.483799][ T8404] del_gendisk+0x24b/0xa00 [ 57.488892][ T8404] loop_control_ioctl+0x3e7/0x4c0 [ 57.494421][ T8404] __x64_sys_ioctl+0x193/0x200 [ 57.499685][ T8404] do_syscall_64+0x3a/0xb0 [ 57.504605][ T8404] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.511089][ T8404] [ 57.511089][ T8404] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 57.518709][ T8404] __lock_acquire+0x2a17/0x5230 [ 57.524070][ T8404] lock_acquire+0x1ab/0x740 [ 57.529163][ T8404] __mutex_lock+0x139/0x10c0 [ 57.534258][ T8404] loop_probe+0xc7/0x150 [ 57.539086][ T8404] blk_request_module+0x111/0x1d0 [ 57.544614][ T8404] blkdev_get_no_open+0x1d8/0x250 [ 57.550139][ T8404] blkdev_get_by_dev+0x76/0x660 [ 57.555493][ T8404] blkdev_open+0x154/0x2b0 [ 57.560410][ T8404] do_dentry_open+0x4b9/0x11b0 [ 57.565679][ T8404] path_openat+0x1c0e/0x27e0 [ 57.570860][ T8404] do_filp_open+0x190/0x3d0 [ 57.575864][ T8404] do_sys_openat2+0x16d/0x420 [ 57.581038][ T8404] __x64_sys_open+0x119/0x1c0 [ 57.586374][ T8404] do_syscall_64+0x3a/0xb0 [ 57.591291][ T8404] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.597684][ T8404] [ 57.597684][ T8404] other info that might help us debug this: [ 57.597684][ T8404] [ 57.607971][ T8404] Chain exists of: [ 57.607971][ T8404] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 57.607971][ T8404] [ 57.621149][ T8404] Possible unsafe locking scenario: [ 57.621149][ T8404] [ 57.628574][ T8404] CPU0 CPU1 [ 57.633930][ T8404] ---- ---- [ 57.639271][ T8404] lock(major_names_lock); [ 57.643753][ T8404] lock(mtd_table_mutex); [ 57.650663][ T8404] lock(major_names_lock); [ 57.657662][ T8404] lock(loop_ctl_mutex); [ 57.662055][ T8404] [ 57.662055][ T8404] *** DEADLOCK *** [ 57.662055][ T8404] [ 57.670173][ T8404] 1 lock held by systemd-udevd/8404: [ 57.675432][ T8404] #0: ffffffff8c7e0368 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 57.685330][ T8404] [ 57.685330][ T8404] stack backtrace: [ 57.691190][ T8404] CPU: 1 PID: 8404 Comm: systemd-udevd Not tainted 5.13.0-rc7-syzkaller #0 [ 57.699768][ T8404] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.709889][ T8404] Call Trace: [ 57.713150][ T8404] dump_stack+0x141/0x1d7 [ 57.717462][ T8404] check_noncircular+0x25f/0x2e0 [ 57.722384][ T8404] ? print_circular_bug+0x1e0/0x1e0 [ 57.727564][ T8404] ? mark_lock+0xef/0x17b0 [ 57.731969][ T8404] ? lockdep_lock+0xc6/0x200 [ 57.736561][ T8404] ? call_rcu_zapped+0xb0/0xb0 [ 57.741325][ T8404] ? tomoyo_check_open_permission+0x172/0x380 [ 57.747462][ T8404] ? security_file_open+0x52/0x4f0 [ 57.752748][ T8404] __lock_acquire+0x2a17/0x5230 [ 57.757586][ T8404] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 57.763554][ T8404] lock_acquire+0x1ab/0x740 [ 57.768048][ T8404] ? loop_probe+0xc7/0x150 [ 57.772449][ T8404] ? lock_release+0x720/0x720 [ 57.777113][ T8404] __mutex_lock+0x139/0x10c0 [ 57.781686][ T8404] ? loop_probe+0xc7/0x150 [ 57.786084][ T8404] ? loop_probe+0xc7/0x150 [ 57.790921][ T8404] ? mutex_lock_io_nested+0xf20/0xf20 [ 57.796279][ T8404] ? __mutex_lock+0x5d5/0x10c0 [ 57.801026][ T8404] ? blk_request_module+0x25/0x1d0 [ 57.806129][ T8404] ? find_held_lock+0x2d/0x110 [ 57.810877][ T8404] ? mutex_lock_io_nested+0xf20/0xf20 [ 57.816411][ T8404] ? ilookup+0xb3/0x230 [ 57.820550][ T8404] loop_probe+0xc7/0x150 [ 57.824865][ T8404] ? loop_control_ioctl+0x4c0/0x4c0 [ 57.830052][ T8404] ? find_inode_fast+0x16f/0x220 [ 57.834976][ T8404] ? do_raw_spin_unlock+0x171/0x230 [ 57.840153][ T8404] ? loop_control_ioctl+0x4c0/0x4c0 [ 57.845438][ T8404] blk_request_module+0x111/0x1d0 [ 57.850450][ T8404] blkdev_get_no_open+0x1d8/0x250 [ 57.855458][ T8404] blkdev_get_by_dev+0x76/0x660 [ 57.861733][ T8404] blkdev_open+0x154/0x2b0 [ 57.867646][ T8404] do_dentry_open+0x4b9/0x11b0 [ 57.872863][ T8404] ? blkdev_get_by_dev+0x660/0x660 [ 57.878324][ T8404] ? may_open+0x1f6/0x420 [ 57.883084][ T8404] path_openat+0x1c0e/0x27e0 [ 57.887686][ T8404] ? path_lookupat+0x850/0x850 [ 57.893039][ T8404] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 57.899117][ T8404] do_filp_open+0x190/0x3d0 [ 57.903787][ T8404] ? may_open_dev+0xf0/0xf0 [ 57.909460][ T8404] ? do_raw_spin_lock+0x120/0x2b0 [ 57.914546][ T8404] ? rwlock_bug.part.0+0x90/0x90 [ 57.919464][ T8404] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 57.925692][ T8404] ? _find_next_bit+0x1e3/0x260 [ 57.930543][ T8404] ? _raw_spin_unlock+0x24/0x40 [ 57.935378][ T8404] ? alloc_fd+0x2e6/0x660 [ 57.939695][ T8404] do_sys_openat2+0x16d/0x420 [ 57.944356][ T8404] ? build_open_flags+0x6f0/0x6f0 [ 57.949362][ T8404] ? __context_tracking_exit+0xb8/0xe0 [ 57.954802][ T8404] __x64_sys_open+0x119/0x1c0 [ 57.959461][ T8404] ? do_sys_open+0x140/0x140 [ 57.964296][ T8404] ? __secure_computing+0x104/0x360 [ 57.969477][ T8404] do_syscall_64+0x3a/0xb0 [ 57.973881][ T8404] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.979844][ T8404] RIP: 0033:0x7efe609bf840 [ 57.984243][ T8404] 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 [ 58.004009][ T8404] RSP: 002b:00007fff87cd20f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 58.012504][ T8404] RAX: ffffffffffffffda RBX: 000055cdd9f4e8f0 RCX: 00007efe609bf840 [ 58.020461][ T8404] RDX: 000055cdd98d1fe3 RSI: 00000000000a0800 RDI: 000055cdd9f4e830 [ 58.028415][ T8404] RBP: 00007fff87cd2270 R08: 000055cdd98d1670 R09: 0000000000000010 [ 58.036366][ T8404] R10: 00007efe60739d70 R11: 0000000000000246 R12: 00007fff87cd21c0 [ 58.044333][ T8404] R13: 000055cdd9f50010 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program