Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.172' (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 syzkaller login: [ 57.555783][ T8720] [ 57.558305][ T8720] ====================================================== [ 57.565293][ T8720] WARNING: possible circular locking dependency detected [ 57.572280][ T8720] 5.14.0-rc6-syzkaller #0 Not tainted [ 57.577708][ T8720] ------------------------------------------------------ [ 57.584695][ T8720] systemd-udevd/8720 is trying to acquire lock: [ 57.590906][ T8720] ffffffff8c486d68 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 57.599321][ T8720] [ 57.599321][ T8720] but task is already holding lock: [ 57.606655][ T8720] ffffffff8c1f4068 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 57.616104][ T8720] [ 57.616104][ T8720] which lock already depends on the new lock. [ 57.616104][ T8720] [ 57.626562][ T8720] [ 57.626562][ T8720] the existing dependency chain (in reverse order) is: [ 57.635547][ T8720] [ 57.635547][ T8720] -> #3 (major_names_lock){+.+.}-{3:3}: [ 57.643247][ T8720] __mutex_lock+0x12a/0x10a0 [ 57.648381][ T8720] __register_blkdev+0x2b/0x3e0 [ 57.653753][ T8720] register_mtd_blktrans+0x85/0x3c0 [ 57.659449][ T8720] do_one_initcall+0x103/0x650 [ 57.664714][ T8720] kernel_init_freeable+0x6b8/0x741 [ 57.670420][ T8720] kernel_init+0x1a/0x1d0 [ 57.675248][ T8720] ret_from_fork+0x1f/0x30 [ 57.680162][ T8720] [ 57.680162][ T8720] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 57.687773][ T8720] __mutex_lock+0x12a/0x10a0 [ 57.692864][ T8720] blktrans_open+0x69/0x600 [ 57.697862][ T8720] blkdev_get_whole+0xa1/0x420 [ 57.703121][ T8720] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 57.709169][ T8720] blkdev_open+0x295/0x300 [ 57.714092][ T8720] do_dentry_open+0x4c8/0x11d0 [ 57.719462][ T8720] path_openat+0x1c23/0x27f0 [ 57.724548][ T8720] do_filp_open+0x1aa/0x400 [ 57.729548][ T8720] do_sys_openat2+0x16d/0x420 [ 57.734722][ T8720] __x64_sys_open+0x119/0x1c0 [ 57.739956][ T8720] do_syscall_64+0x35/0xb0 [ 57.744869][ T8720] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.751260][ T8720] [ 57.751260][ T8720] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 57.759050][ T8720] __mutex_lock+0x12a/0x10a0 [ 57.764137][ T8720] del_gendisk+0x8b/0x770 [ 57.768969][ T8720] loop_control_ioctl+0x3b5/0x450 [ 57.774490][ T8720] __x64_sys_ioctl+0x193/0x200 [ 57.779757][ T8720] do_syscall_64+0x35/0xb0 [ 57.784674][ T8720] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.791062][ T8720] [ 57.791062][ T8720] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 57.798588][ T8720] __lock_acquire+0x2a07/0x54a0 [ 57.803934][ T8720] lock_acquire+0x1ab/0x510 [ 57.808990][ T8720] __mutex_lock+0x12a/0x10a0 [ 57.814131][ T8720] loop_add+0x9c/0x8c0 [ 57.818699][ T8720] loop_probe+0x6a/0x80 [ 57.823353][ T8720] blk_request_module+0x111/0x1d0 [ 57.828932][ T8720] blkdev_get_no_open+0x1d5/0x250 [ 57.834454][ T8720] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 57.840428][ T8720] blkdev_open+0x295/0x300 [ 57.845339][ T8720] do_dentry_open+0x4c8/0x11d0 [ 57.850602][ T8720] path_openat+0x1c23/0x27f0 [ 57.855690][ T8720] do_filp_open+0x1aa/0x400 [ 57.860691][ T8720] do_sys_openat2+0x16d/0x420 [ 57.865866][ T8720] __x64_sys_open+0x119/0x1c0 [ 57.871042][ T8720] do_syscall_64+0x35/0xb0 [ 57.875956][ T8720] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 57.882346][ T8720] [ 57.882346][ T8720] other info that might help us debug this: [ 57.882346][ T8720] [ 57.892545][ T8720] Chain exists of: [ 57.892545][ T8720] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 57.892545][ T8720] [ 57.905542][ T8720] Possible unsafe locking scenario: [ 57.905542][ T8720] [ 57.913049][ T8720] CPU0 CPU1 [ 57.918391][ T8720] ---- ---- [ 57.923729][ T8720] lock(major_names_lock); [ 57.928207][ T8720] lock(mtd_table_mutex); [ 57.935118][ T8720] lock(major_names_lock); [ 57.942121][ T8720] lock(loop_ctl_mutex); [ 57.946426][ T8720] [ 57.946426][ T8720] *** DEADLOCK *** [ 57.946426][ T8720] [ 57.954541][ T8720] 1 lock held by systemd-udevd/8720: [ 57.959797][ T8720] #0: ffffffff8c1f4068 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 57.969689][ T8720] [ 57.969689][ T8720] stack backtrace: [ 57.975551][ T8720] CPU: 0 PID: 8720 Comm: systemd-udevd Not tainted 5.14.0-rc6-syzkaller #0 [ 57.984196][ T8720] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.994227][ T8720] Call Trace: [ 57.997494][ T8720] dump_stack_lvl+0xcd/0x134 [ 58.002077][ T8720] check_noncircular+0x25f/0x2e0 [ 58.006991][ T8720] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 58.012947][ T8720] ? print_circular_bug+0x1e0/0x1e0 [ 58.018121][ T8720] ? lock_chain_count+0x20/0x20 [ 58.022954][ T8720] ? lockdep_lock+0xc6/0x200 [ 58.027521][ T8720] ? call_rcu_zapped+0xb0/0xb0 [ 58.032262][ T8720] __lock_acquire+0x2a07/0x54a0 [ 58.037088][ T8720] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 58.043048][ T8720] lock_acquire+0x1ab/0x510 [ 58.047528][ T8720] ? loop_add+0x9c/0x8c0 [ 58.051749][ T8720] ? lock_release+0x720/0x720 [ 58.056401][ T8720] ? path_openat+0x1c23/0x27f0 [ 58.061145][ T8720] ? do_filp_open+0x1aa/0x400 [ 58.065800][ T8720] ? do_sys_openat2+0x16d/0x420 [ 58.070639][ T8720] ? __x64_sys_open+0x119/0x1c0 [ 58.075564][ T8720] __mutex_lock+0x12a/0x10a0 [ 58.080145][ T8720] ? loop_add+0x9c/0x8c0 [ 58.084363][ T8720] ? loop_add+0x9c/0x8c0 [ 58.088586][ T8720] ? mutex_lock_io_nested+0xf00/0xf00 [ 58.093948][ T8720] ? rcu_read_lock_sched_held+0x3a/0x70 [ 58.099650][ T8720] loop_add+0x9c/0x8c0 [ 58.103694][ T8720] ? find_inode_fast+0x16f/0x220 [ 58.108611][ T8720] loop_probe+0x6a/0x80 [ 58.112742][ T8720] ? loop_add+0x8c0/0x8c0 [ 58.117046][ T8720] blk_request_module+0x111/0x1d0 [ 58.122048][ T8720] blkdev_get_no_open+0x1d5/0x250 [ 58.127048][ T8720] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 58.132486][ T8720] ? devcgroup_check_permission+0x1bb/0x410 [ 58.138447][ T8720] blkdev_open+0x295/0x300 [ 58.142848][ T8720] do_dentry_open+0x4c8/0x11d0 [ 58.147591][ T8720] ? blkdev_get_by_dev+0x80/0x80 [ 58.152504][ T8720] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 58.158723][ T8720] ? may_open+0x1f6/0x420 [ 58.163032][ T8720] path_openat+0x1c23/0x27f0 [ 58.167599][ T8720] ? path_lookupat+0x860/0x860 [ 58.172343][ T8720] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 58.178490][ T8720] do_filp_open+0x1aa/0x400 [ 58.182969][ T8720] ? may_open_dev+0xf0/0xf0 [ 58.187451][ T8720] ? rwlock_bug.part.0+0x90/0x90 [ 58.192363][ T8720] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 58.198577][ T8720] ? _find_next_bit+0x1e3/0x260 [ 58.203405][ T8720] ? _raw_spin_unlock+0x24/0x40 [ 58.208234][ T8720] ? alloc_fd+0x2f0/0x670 [ 58.212543][ T8720] do_sys_openat2+0x16d/0x420 [ 58.217197][ T8720] ? build_open_flags+0x6f0/0x6f0 [ 58.222199][ T8720] ? __context_tracking_exit+0xb8/0xe0 [ 58.227639][ T8720] __x64_sys_open+0x119/0x1c0 [ 58.232295][ T8720] ? do_sys_open+0x140/0x140 [ 58.237037][ T8720] ? __secure_computing+0x104/0x360 [ 58.242213][ T8720] do_syscall_64+0x35/0xb0 [ 58.246607][ T8720] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 58.252479][ T8720] RIP: 0033:0x7fc70f33e840 [ 58.256884][ T8720] 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 [ 58.276467][ T8720] RSP: 002b:00007ffce3344508 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 58.284857][ T8720] RAX: ffffffffffffffda RBX: 00005599372d2270 RCX: 00007fc70f33e840 [ 58.292893][ T8720] RDX: 0000559936817fe3 RSI: 00000000000a0800 RDI: 00005599372d1f80 [ 58.300842][ T8720] RBP: 00007ffce3344680 R08: 0000559936817670 R09: 0000000000000010 executing program executing program executing program executing program [ 58.308789][ T8720] R10: 00007fc70f0b8d70 R11: 0000000000000246 R12: 00007ffce33445d0 [ 58.316738][ T8720] R13: 00005599372d2370 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 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executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program