[ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ 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. Warning: Permanently added '10.128.0.70' (ECDSA) to the list of known hosts. executing program [ 73.890982][ T37] audit: type=1400 audit(1624057297.220:8): avc: denied { execmem } for pid=8439 comm="syz-executor970" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program Debian GNU/Linux 9 syzkaller ttyS0 executing program executing program executing program 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: [ 74.596466][ T8530] [ 74.598837][ T8530] ====================================================== [ 74.605849][ T8530] WARNING: possible circular locking dependency detected [ 74.613001][ T8530] 5.13.0-rc6-syzkaller #0 Not tainted [ 74.618351][ T8530] ------------------------------------------------------ [ 74.625343][ T8530] systemd-udevd/8530 is trying to acquire lock: [ 74.631567][ T8530] ffffffff8ca6c6c8 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_probe+0xc7/0x150 [ 74.640271][ T8530] [ 74.640271][ T8530] but task is already holding lock: [ 74.647613][ T8530] ffffffff8c7dec48 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 74.657110][ T8530] [ 74.657110][ T8530] which lock already depends on the new lock. [ 74.657110][ T8530] [ 74.667488][ T8530] [ 74.667488][ T8530] the existing dependency chain (in reverse order) is: [ 74.676505][ T8530] [ 74.676505][ T8530] -> #3 (major_names_lock){+.+.}-{3:3}: [ 74.684217][ T8530] __mutex_lock+0x139/0x10c0 [ 74.689321][ T8530] __register_blkdev+0x2b/0x3e0 [ 74.694683][ T8530] register_mtd_blktrans+0x85/0x3c0 [ 74.700399][ T8530] do_one_initcall+0x103/0x650 [ 74.705680][ T8530] kernel_init_freeable+0x6c4/0x74d [ 74.711392][ T8530] kernel_init+0xd/0x1b8 [ 74.716136][ T8530] ret_from_fork+0x1f/0x30 [ 74.721055][ T8530] [ 74.721055][ T8530] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 74.728671][ T8530] __mutex_lock+0x139/0x10c0 [ 74.733872][ T8530] blktrans_open+0x69/0x600 [ 74.738886][ T8530] __blkdev_get+0x182/0xa30 [ 74.743890][ T8530] blkdev_get_by_dev+0x200/0x660 [ 74.749327][ T8530] blkdev_open+0x154/0x2b0 [ 74.754243][ T8530] do_dentry_open+0x4b9/0x11b0 [ 74.759514][ T8530] path_openat+0x1c0e/0x27e0 [ 74.764619][ T8530] do_filp_open+0x190/0x3d0 [ 74.769859][ T8530] do_sys_openat2+0x16d/0x420 [ 74.775043][ T8530] __x64_sys_open+0x119/0x1c0 [ 74.780227][ T8530] do_syscall_64+0x3a/0xb0 [ 74.785147][ T8530] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 74.791543][ T8530] [ 74.791543][ T8530] -> #1 (&bdev->bd_mutex){+.+.}-{3:3}: [ 74.799167][ T8530] __mutex_lock+0x139/0x10c0 [ 74.804260][ T8530] del_gendisk+0x24b/0xa00 [ 74.809181][ T8530] loop_control_ioctl+0x3e7/0x4c0 [ 74.814709][ T8530] __x64_sys_ioctl+0x193/0x200 [ 74.819979][ T8530] do_syscall_64+0x3a/0xb0 [ 74.824902][ T8530] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 74.831297][ T8530] [ 74.831297][ T8530] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 74.838827][ T8530] __lock_acquire+0x2a17/0x5230 [ 74.844184][ T8530] lock_acquire+0x1ab/0x740 [ 74.849190][ T8530] __mutex_lock+0x139/0x10c0 [ 74.854276][ T8530] loop_probe+0xc7/0x150 [ 74.859020][ T8530] blk_request_module+0x111/0x1d0 [ 74.864569][ T8530] blkdev_get_no_open+0x1d8/0x250 [ 74.870092][ T8530] blkdev_get_by_dev+0x76/0x660 [ 74.875441][ T8530] blkdev_open+0x154/0x2b0 [ 74.880358][ T8530] do_dentry_open+0x4b9/0x11b0 [ 74.885640][ T8530] path_openat+0x1c0e/0x27e0 [ 74.890731][ T8530] do_filp_open+0x190/0x3d0 [ 74.895735][ T8530] do_sys_openat2+0x16d/0x420 [ 74.900914][ T8530] __x64_sys_open+0x119/0x1c0 [ 74.906091][ T8530] do_syscall_64+0x3a/0xb0 [ 74.911008][ T8530] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 74.917400][ T8530] [ 74.917400][ T8530] other info that might help us debug this: [ 74.917400][ T8530] [ 74.927617][ T8530] Chain exists of: [ 74.927617][ T8530] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 74.927617][ T8530] [ 74.940716][ T8530] Possible unsafe locking scenario: [ 74.940716][ T8530] [ 74.948151][ T8530] CPU0 CPU1 [ 74.953491][ T8530] ---- ---- [ 74.958849][ T8530] lock(major_names_lock); [ 74.963329][ T8530] lock(mtd_table_mutex); [ 74.970276][ T8530] lock(major_names_lock); [ 74.977274][ T8530] lock(loop_ctl_mutex); [ 74.981582][ T8530] [ 74.981582][ T8530] *** DEADLOCK *** [ 74.981582][ T8530] [ 74.989700][ T8530] 1 lock held by systemd-udevd/8530: [ 74.994982][ T8530] #0: ffffffff8c7dec48 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 75.004978][ T8530] [ 75.004978][ T8530] stack backtrace: [ 75.010862][ T8530] CPU: 0 PID: 8530 Comm: systemd-udevd Not tainted 5.13.0-rc6-syzkaller #0 [ 75.019441][ T8530] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 75.029485][ T8530] Call Trace: [ 75.032759][ T8530] dump_stack+0x141/0x1d7 [ 75.037079][ T8530] check_noncircular+0x25f/0x2e0 [ 75.042003][ T8530] ? print_circular_bug+0x1e0/0x1e0 [ 75.047184][ T8530] ? mark_lock+0xef/0x17b0 [ 75.051584][ T8530] ? lockdep_lock+0xc6/0x200 [ 75.056170][ T8530] ? call_rcu_zapped+0xb0/0xb0 [ 75.060926][ T8530] __lock_acquire+0x2a17/0x5230 [ 75.065760][ T8530] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 75.071733][ T8530] lock_acquire+0x1ab/0x740 [ 75.076218][ T8530] ? loop_probe+0xc7/0x150 [ 75.080613][ T8530] ? lock_release+0x720/0x720 [ 75.085270][ T8530] __mutex_lock+0x139/0x10c0 [ 75.089854][ T8530] ? loop_probe+0xc7/0x150 [ 75.094252][ T8530] ? loop_probe+0xc7/0x150 [ 75.098663][ T8530] ? mutex_lock_io_nested+0xf20/0xf20 [ 75.104025][ T8530] ? __mutex_lock+0x5d5/0x10c0 [ 75.108781][ T8530] ? blk_request_module+0x25/0x1d0 [ 75.113870][ T8530] ? find_held_lock+0x2d/0x110 [ 75.118614][ T8530] ? mutex_lock_io_nested+0xf20/0xf20 [ 75.123964][ T8530] ? ilookup+0xb3/0x230 [ 75.128099][ T8530] loop_probe+0xc7/0x150 [ 75.132323][ T8530] ? loop_control_ioctl+0x4c0/0x4c0 [ 75.137500][ T8530] ? find_inode_fast+0x16f/0x220 [ 75.142423][ T8530] ? do_raw_spin_unlock+0x171/0x230 [ 75.147602][ T8530] ? loop_control_ioctl+0x4c0/0x4c0 [ 75.152782][ T8530] blk_request_module+0x111/0x1d0 [ 75.157786][ T8530] blkdev_get_no_open+0x1d8/0x250 [ 75.162787][ T8530] blkdev_get_by_dev+0x76/0x660 [ 75.167615][ T8530] blkdev_open+0x154/0x2b0 [ 75.172016][ T8530] do_dentry_open+0x4b9/0x11b0 [ 75.176758][ T8530] ? blkdev_get_by_dev+0x660/0x660 [ 75.181846][ T8530] ? may_open+0x1f6/0x420 [ 75.186156][ T8530] path_openat+0x1c0e/0x27e0 [ 75.190726][ T8530] ? path_lookupat+0x850/0x850 [ 75.195466][ T8530] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 75.201448][ T8530] do_filp_open+0x190/0x3d0 [ 75.205943][ T8530] ? may_open_dev+0xf0/0xf0 [ 75.210427][ T8530] ? do_raw_spin_lock+0x120/0x2b0 [ 75.215438][ T8530] ? rwlock_bug.part.0+0x90/0x90 [ 75.220362][ T8530] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 75.226586][ T8530] ? _find_next_bit+0x1e3/0x260 [ 75.231416][ T8530] ? _raw_spin_unlock+0x24/0x40 [ 75.236252][ T8530] ? alloc_fd+0x2e6/0x660 [ 75.240571][ T8530] do_sys_openat2+0x16d/0x420 [ 75.245231][ T8530] ? build_open_flags+0x6f0/0x6f0 [ 75.250254][ T8530] ? __context_tracking_exit+0xb8/0xe0 [ 75.255702][ T8530] __x64_sys_open+0x119/0x1c0 [ 75.260373][ T8530] ? do_sys_open+0x140/0x140 [ 75.264944][ T8530] ? __secure_computing+0x104/0x360 [ 75.270123][ T8530] do_syscall_64+0x3a/0xb0 [ 75.274535][ T8530] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 75.280411][ T8530] RIP: 0033:0x7fb1ec25c840 [ 75.284809][ T8530] 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 [ 75.304484][ T8530] RSP: 002b:00007ffe498b77d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 75.312877][ T8530] RAX: ffffffffffffffda RBX: 00005629c8a19c00 RCX: 00007fb1ec25c840 [ 75.320836][ T8530] RDX: 00005629c7a9dfe3 RSI: 00000000000a0800 RDI: 00005629c8a2d050 [ 75.328787][ T8530] RBP: 00007ffe498b7950 R08: 00005629c7a9d670 R09: 0000000000000010 [ 75.336748][ T8530] R10: 00005629c7a9dd0c R11: 0000000000000246 R12: 00007ffe498b78a0 [ 75.344697][ T8530] R13: 00005629c8a2cc00 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program