[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.106' (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 syzkaller login: [ 73.023436][ T8542] [ 73.025990][ T8542] ====================================================== [ 73.033137][ T8542] WARNING: possible circular locking dependency detected [ 73.040147][ T8542] 5.14.0-rc5-syzkaller #0 Not tainted [ 73.045495][ T8542] ------------------------------------------------------ [ 73.052501][ T8542] systemd-udevd/8542 is trying to acquire lock: [ 73.058726][ T8542] ffffffff8c486b88 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 73.067286][ T8542] [ 73.067286][ T8542] but task is already holding lock: [ 73.074738][ T8542] ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 73.084234][ T8542] [ 73.084234][ T8542] which lock already depends on the new lock. [ 73.084234][ T8542] [ 73.094625][ T8542] [ 73.094625][ T8542] the existing dependency chain (in reverse order) is: [ 73.103639][ T8542] [ 73.103639][ T8542] -> #3 (major_names_lock){+.+.}-{3:3}: [ 73.111362][ T8542] __mutex_lock+0x12a/0x10a0 [ 73.116497][ T8542] __register_blkdev+0x2b/0x3e0 [ 73.121856][ T8542] register_mtd_blktrans+0x85/0x3c0 [ 73.127563][ T8542] do_one_initcall+0x103/0x650 [ 73.132922][ T8542] kernel_init_freeable+0x6b8/0x741 [ 73.138626][ T8542] kernel_init+0x1a/0x1d0 [ 73.143459][ T8542] ret_from_fork+0x1f/0x30 [ 73.148473][ T8542] [ 73.148473][ T8542] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 73.156092][ T8542] __mutex_lock+0x12a/0x10a0 [ 73.161182][ T8542] blktrans_open+0x69/0x600 [ 73.166292][ T8542] blkdev_get_whole+0xa1/0x420 [ 73.171555][ T8542] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 73.177614][ T8542] blkdev_open+0x295/0x300 [ 73.182530][ T8542] do_dentry_open+0x4c8/0x11d0 [ 73.187805][ T8542] path_openat+0x1c23/0x27f0 [ 73.193095][ T8542] do_filp_open+0x1aa/0x400 [ 73.198098][ T8542] do_sys_openat2+0x16d/0x420 [ 73.203289][ T8542] __x64_sys_open+0x119/0x1c0 [ 73.208467][ T8542] do_syscall_64+0x35/0xb0 [ 73.213396][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.219789][ T8542] [ 73.219789][ T8542] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 73.227581][ T8542] __mutex_lock+0x12a/0x10a0 [ 73.232691][ T8542] del_gendisk+0x8b/0x770 [ 73.237538][ T8542] loop_control_ioctl+0x3b5/0x450 [ 73.243080][ T8542] __do_compat_sys_ioctl+0x1c7/0x290 [ 73.248877][ T8542] __do_fast_syscall_32+0x65/0xf0 [ 73.254410][ T8542] do_fast_syscall_32+0x2f/0x70 [ 73.259883][ T8542] entry_SYSENTER_compat_after_hwframe+0x4d/0x5c [ 73.266811][ T8542] [ 73.266811][ T8542] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 73.274356][ T8542] __lock_acquire+0x2a07/0x54a0 [ 73.279722][ T8542] lock_acquire+0x1ab/0x510 [ 73.284744][ T8542] __mutex_lock+0x12a/0x10a0 [ 73.289858][ T8542] loop_add+0x9c/0x8c0 [ 73.294433][ T8542] loop_probe+0x6a/0x80 [ 73.299178][ T8542] blk_request_module+0x111/0x1d0 [ 73.304711][ T8542] blkdev_get_no_open+0x1d5/0x250 [ 73.310347][ T8542] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 73.316307][ T8542] blkdev_open+0x295/0x300 [ 73.321457][ T8542] do_dentry_open+0x4c8/0x11d0 [ 73.326879][ T8542] path_openat+0x1c23/0x27f0 [ 73.331986][ T8542] do_filp_open+0x1aa/0x400 [ 73.337003][ T8542] do_sys_openat2+0x16d/0x420 [ 73.342303][ T8542] __x64_sys_open+0x119/0x1c0 [ 73.347839][ T8542] do_syscall_64+0x35/0xb0 [ 73.352816][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.360183][ T8542] [ 73.360183][ T8542] other info that might help us debug this: [ 73.360183][ T8542] [ 73.370512][ T8542] Chain exists of: [ 73.370512][ T8542] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 73.370512][ T8542] [ 73.383526][ T8542] Possible unsafe locking scenario: [ 73.383526][ T8542] [ 73.390954][ T8542] CPU0 CPU1 [ 73.396293][ T8542] ---- ---- [ 73.401649][ T8542] lock(major_names_lock); [ 73.406130][ T8542] lock(mtd_table_mutex); [ 73.413040][ T8542] lock(major_names_lock); [ 73.420040][ T8542] lock(loop_ctl_mutex); [ 73.424347][ T8542] [ 73.424347][ T8542] *** DEADLOCK *** [ 73.424347][ T8542] [ 73.432470][ T8542] 1 lock held by systemd-udevd/8542: [ 73.437728][ T8542] #0: ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 73.447623][ T8542] [ 73.447623][ T8542] stack backtrace: [ 73.453486][ T8542] CPU: 1 PID: 8542 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 [ 73.462050][ T8542] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.472454][ T8542] Call Trace: [ 73.475832][ T8542] dump_stack_lvl+0xcd/0x134 [ 73.480412][ T8542] check_noncircular+0x25f/0x2e0 [ 73.485421][ T8542] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.491401][ T8542] ? print_circular_bug+0x1e0/0x1e0 [ 73.496585][ T8542] ? lock_chain_count+0x20/0x20 [ 73.501430][ T8542] ? lockdep_lock+0xc6/0x200 [ 73.506014][ T8542] ? call_rcu_zapped+0xb0/0xb0 [ 73.510796][ T8542] __lock_acquire+0x2a07/0x54a0 [ 73.515738][ T8542] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.521702][ T8542] lock_acquire+0x1ab/0x510 [ 73.526183][ T8542] ? loop_add+0x9c/0x8c0 [ 73.530408][ T8542] ? lock_release+0x720/0x720 [ 73.535151][ T8542] ? path_openat+0x1c23/0x27f0 [ 73.539910][ T8542] ? do_filp_open+0x1aa/0x400 [ 73.544567][ T8542] ? do_sys_openat2+0x16d/0x420 [ 73.549420][ T8542] ? __x64_sys_open+0x119/0x1c0 [ 73.554268][ T8542] __mutex_lock+0x12a/0x10a0 [ 73.559137][ T8542] ? loop_add+0x9c/0x8c0 [ 73.563399][ T8542] ? loop_add+0x9c/0x8c0 [ 73.567884][ T8542] ? mutex_lock_io_nested+0xf00/0xf00 [ 73.573432][ T8542] ? rcu_read_lock_sched_held+0x3a/0x70 [ 73.578997][ T8542] loop_add+0x9c/0x8c0 [ 73.583171][ T8542] ? find_inode_fast+0x16f/0x220 [ 73.588219][ T8542] loop_probe+0x6a/0x80 [ 73.592491][ T8542] ? loop_add+0x8c0/0x8c0 [ 73.597020][ T8542] blk_request_module+0x111/0x1d0 [ 73.602057][ T8542] blkdev_get_no_open+0x1d5/0x250 [ 73.607210][ T8542] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 73.612673][ T8542] ? devcgroup_check_permission+0x1bb/0x410 [ 73.618659][ T8542] blkdev_open+0x295/0x300 [ 73.623067][ T8542] do_dentry_open+0x4c8/0x11d0 [ 73.627821][ T8542] ? blkdev_get_by_dev+0x80/0x80 [ 73.632966][ T8542] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.639204][ T8542] ? may_open+0x1f6/0x420 [ 73.644076][ T8542] path_openat+0x1c23/0x27f0 [ 73.648750][ T8542] ? path_lookupat+0x860/0x860 [ 73.653585][ T8542] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.659656][ T8542] do_filp_open+0x1aa/0x400 [ 73.664739][ T8542] ? may_open_dev+0xf0/0xf0 [ 73.669549][ T8542] ? rwlock_bug.part.0+0x90/0x90 [ 73.674777][ T8542] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 73.681023][ T8542] ? _find_next_bit+0x1e3/0x260 [ 73.685869][ T8542] ? _raw_spin_unlock+0x24/0x40 [ 73.690737][ T8542] ? alloc_fd+0x2f0/0x670 [ 73.695059][ T8542] do_sys_openat2+0x16d/0x420 [ 73.699753][ T8542] ? build_open_flags+0x6f0/0x6f0 [ 73.704768][ T8542] ? __context_tracking_exit+0xb8/0xe0 [ 73.710216][ T8542] __x64_sys_open+0x119/0x1c0 [ 73.714893][ T8542] ? do_sys_open+0x140/0x140 [ 73.719481][ T8542] ? __secure_computing+0x104/0x360 [ 73.724671][ T8542] do_syscall_64+0x35/0xb0 [ 73.729080][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.734970][ T8542] RIP: 0033:0x7f3d92759840 [ 73.739377][ T8542] 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 [ 73.759499][ T8542] RSP: 002b:00007ffd606f1bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 73.768021][ T8542] RAX: ffffffffffffffda RBX: 000055859844f8f0 RCX: 00007f3d92759840 executing program executing program [ 73.775973][ T8542] RDX: 00005585976cffe3 RSI: 00000000000a0800 RDI: 000055859844f830 [ 73.783922][ T8542] RBP: 00007ffd606f1d50 R08: 00005585976cf670 R09: 0000000000000010 [ 73.791881][ T8542] R10: 00005585976cfd0c R11: 0000000000000246 R12: 00007ffd606f1ca0 [ 73.800025][ T8542] R13: 0000558598451010 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