[ 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... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.121' (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 syzkaller login: [ 85.073679][ T8556] [ 85.076341][ T8556] ====================================================== [ 85.084340][ T8556] WARNING: possible circular locking dependency detected [ 85.091555][ T8556] 5.13.0-rc7-syzkaller #0 Not tainted [ 85.097513][ T8556] ------------------------------------------------------ [ 85.105487][ T8556] systemd-udevd/8556 is trying to acquire lock: [ 85.112213][ T8556] ffffffff8ca6dca8 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_probe+0xc7/0x150 [ 85.120922][ T8556] [ 85.120922][ T8556] but task is already holding lock: [ 85.128297][ T8556] ffffffff8c7e01e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 85.138060][ T8556] [ 85.138060][ T8556] which lock already depends on the new lock. [ 85.138060][ T8556] [ 85.148746][ T8556] [ 85.148746][ T8556] the existing dependency chain (in reverse order) is: [ 85.158128][ T8556] [ 85.158128][ T8556] -> #3 (major_names_lock){+.+.}-{3:3}: [ 85.165985][ T8556] __mutex_lock+0x139/0x10c0 [ 85.171407][ T8556] __register_blkdev+0x2b/0x3e0 [ 85.177104][ T8556] register_mtd_blktrans+0x85/0x3c0 [ 85.183192][ T8556] do_one_initcall+0x103/0x650 [ 85.188589][ T8556] kernel_init_freeable+0x6c4/0x74d [ 85.194306][ T8556] kernel_init+0xd/0x1b8 [ 85.199145][ T8556] ret_from_fork+0x1f/0x30 [ 85.204172][ T8556] [ 85.204172][ T8556] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 85.212216][ T8556] __mutex_lock+0x139/0x10c0 [ 85.217430][ T8556] blktrans_open+0x69/0x600 [ 85.222694][ T8556] __blkdev_get+0x182/0xa30 [ 85.228100][ T8556] blkdev_get_by_dev+0x200/0x660 [ 85.233883][ T8556] blkdev_open+0x154/0x2b0 [ 85.239120][ T8556] do_dentry_open+0x4b9/0x11b0 [ 85.244743][ T8556] path_openat+0x1c0e/0x27e0 [ 85.250706][ T8556] do_filp_open+0x190/0x3d0 [ 85.255998][ T8556] do_sys_openat2+0x16d/0x420 [ 85.261965][ T8556] __x64_sys_open+0x119/0x1c0 [ 85.267802][ T8556] do_syscall_64+0x3a/0xb0 [ 85.272904][ T8556] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 85.279343][ T8556] [ 85.279343][ T8556] -> #1 (&bdev->bd_mutex){+.+.}-{3:3}: [ 85.286992][ T8556] __mutex_lock+0x139/0x10c0 [ 85.292766][ T8556] del_gendisk+0x24b/0xa00 [ 85.297808][ T8556] loop_control_ioctl+0x3e7/0x4c0 [ 85.303466][ T8556] __x64_sys_ioctl+0x193/0x200 [ 85.312477][ T8556] do_syscall_64+0x3a/0xb0 [ 85.317712][ T8556] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 85.324299][ T8556] [ 85.324299][ T8556] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 85.332059][ T8556] __lock_acquire+0x2a17/0x5230 [ 85.337428][ T8556] lock_acquire+0x1ab/0x510 [ 85.342464][ T8556] __mutex_lock+0x139/0x10c0 [ 85.348051][ T8556] loop_probe+0xc7/0x150 [ 85.353060][ T8556] blk_request_module+0x111/0x1d0 [ 85.358671][ T8556] blkdev_get_no_open+0x1d8/0x250 [ 85.364967][ T8556] blkdev_get_by_dev+0x76/0x660 [ 85.370563][ T8556] blkdev_open+0x154/0x2b0 [ 85.376906][ T8556] do_dentry_open+0x4b9/0x11b0 [ 85.383018][ T8556] path_openat+0x1c0e/0x27e0 [ 85.389075][ T8556] do_filp_open+0x190/0x3d0 [ 85.394183][ T8556] do_sys_openat2+0x16d/0x420 [ 85.399512][ T8556] __x64_sys_open+0x119/0x1c0 [ 85.404909][ T8556] do_syscall_64+0x3a/0xb0 [ 85.410109][ T8556] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 85.417035][ T8556] [ 85.417035][ T8556] other info that might help us debug this: [ 85.417035][ T8556] [ 85.427459][ T8556] Chain exists of: [ 85.427459][ T8556] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 85.427459][ T8556] [ 85.441041][ T8556] Possible unsafe locking scenario: [ 85.441041][ T8556] [ 85.448632][ T8556] CPU0 CPU1 [ 85.454123][ T8556] ---- ---- [ 85.459750][ T8556] lock(major_names_lock); [ 85.464583][ T8556] lock(mtd_table_mutex); [ 85.471612][ T8556] lock(major_names_lock); [ 85.478922][ T8556] lock(loop_ctl_mutex); [ 85.483344][ T8556] [ 85.483344][ T8556] *** DEADLOCK *** [ 85.483344][ T8556] [ 85.491497][ T8556] 1 lock held by systemd-udevd/8556: [ 85.497402][ T8556] #0: ffffffff8c7e01e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 85.507876][ T8556] [ 85.507876][ T8556] stack backtrace: [ 85.518555][ T8556] CPU: 0 PID: 8556 Comm: systemd-udevd Not tainted 5.13.0-rc7-syzkaller #0 [ 85.527319][ T8556] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 85.537468][ T8556] Call Trace: [ 85.540929][ T8556] dump_stack+0x141/0x1d7 [ 85.545460][ T8556] check_noncircular+0x25f/0x2e0 [ 85.550744][ T8556] ? print_circular_bug+0x1e0/0x1e0 [ 85.556041][ T8556] ? mark_lock+0xef/0x17b0 [ 85.560481][ T8556] ? lockdep_lock+0xc6/0x200 [ 85.565069][ T8556] ? call_rcu_zapped+0xb0/0xb0 [ 85.569830][ T8556] ? tomoyo_check_open_permission+0x172/0x380 [ 85.575894][ T8556] ? security_file_open+0x52/0x4f0 [ 85.581007][ T8556] __lock_acquire+0x2a17/0x5230 [ 85.585991][ T8556] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 85.592333][ T8556] lock_acquire+0x1ab/0x510 [ 85.597107][ T8556] ? loop_probe+0xc7/0x150 [ 85.601548][ T8556] ? lock_release+0x720/0x720 [ 85.606334][ T8556] __mutex_lock+0x139/0x10c0 [ 85.611443][ T8556] ? loop_probe+0xc7/0x150 [ 85.615960][ T8556] ? loop_probe+0xc7/0x150 [ 85.620744][ T8556] ? mutex_lock_io_nested+0xf20/0xf20 [ 85.626456][ T8556] ? __mutex_lock+0x5d5/0x10c0 [ 85.631229][ T8556] ? blk_request_module+0x25/0x1d0 [ 85.636570][ T8556] ? find_held_lock+0x2d/0x110 [ 85.641341][ T8556] ? mutex_lock_io_nested+0xf20/0xf20 [ 85.646706][ T8556] ? ilookup+0xb3/0x230 [ 85.650872][ T8556] loop_probe+0xc7/0x150 [ 85.655439][ T8556] ? loop_control_ioctl+0x4c0/0x4c0 [ 85.661039][ T8556] ? find_inode_fast+0x16f/0x220 [ 85.666053][ T8556] ? do_raw_spin_unlock+0x171/0x230 [ 85.671238][ T8556] ? loop_control_ioctl+0x4c0/0x4c0 [ 85.676604][ T8556] blk_request_module+0x111/0x1d0 [ 85.681916][ T8556] blkdev_get_no_open+0x1d8/0x250 [ 85.687234][ T8556] blkdev_get_by_dev+0x76/0x660 [ 85.692099][ T8556] blkdev_open+0x154/0x2b0 [ 85.697107][ T8556] do_dentry_open+0x4b9/0x11b0 [ 85.701971][ T8556] ? blkdev_get_by_dev+0x660/0x660 [ 85.707308][ T8556] ? may_open+0x1f6/0x420 [ 85.711868][ T8556] path_openat+0x1c0e/0x27e0 [ 85.716597][ T8556] ? path_lookupat+0x850/0x850 [ 85.721762][ T8556] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 85.728063][ T8556] do_filp_open+0x190/0x3d0 [ 85.732792][ T8556] ? may_open_dev+0xf0/0xf0 [ 85.737676][ T8556] ? do_raw_spin_lock+0x120/0x2b0 [ 85.742723][ T8556] ? rwlock_bug.part.0+0x90/0x90 [ 85.747780][ T8556] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 85.754127][ T8556] ? _find_next_bit+0x1e3/0x260 [ 85.759266][ T8556] ? _raw_spin_unlock+0x24/0x40 [ 85.764108][ T8556] ? alloc_fd+0x2e6/0x660 [ 85.768616][ T8556] do_sys_openat2+0x16d/0x420 [ 85.773397][ T8556] ? build_open_flags+0x6f0/0x6f0 [ 85.778515][ T8556] ? __context_tracking_exit+0xb8/0xe0 [ 85.783960][ T8556] __x64_sys_open+0x119/0x1c0 [ 85.788638][ T8556] ? do_sys_open+0x140/0x140 [ 85.793380][ T8556] ? __secure_computing+0x104/0x360 [ 85.798572][ T8556] do_syscall_64+0x3a/0xb0 [ 85.802983][ T8556] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 85.808976][ T8556] RIP: 0033:0x7f3f410e5840 [ 85.813380][ T8556] 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 [ 85.834573][ T8556] RSP: 002b:00007fff443dee38 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 85.843093][ T8556] RAX: ffffffffffffffda RBX: 00005598938f88f0 RCX: 00007f3f410e5840 [ 85.851750][ T8556] RDX: 0000559892900fe3 RSI: 00000000000a0800 RDI: 00005598938f8830 [ 85.859738][ T8556] RBP: 00007fff443defb0 R08: 0000559892900670 R09: 0000000000000010 [ 85.867704][ T8556] R10: 0000559892900d0c R11: 0000000000000246 R12: 00007fff443def00 executing program executing program executing program [ 85.875864][ T8556] R13: 00005598938fa010 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