[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.29' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 79.579023][ T37] audit: type=1400 audit(1628826832.037:8): avc: denied { execmem } for pid=8437 comm="syz-executor116" 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 [ 79.956057][ T8472] [ 79.958438][ T8472] ====================================================== [ 79.965447][ T8472] WARNING: possible circular locking dependency detected [ 79.972458][ T8472] 5.14.0-rc5-syzkaller #0 Not tainted [ 79.977859][ T8472] ------------------------------------------------------ [ 79.984892][ T8472] systemd-udevd/8472 is trying to acquire lock: [ 79.991127][ T8472] ffffffff8c486148 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 79.999639][ T8472] [ 79.999639][ T8472] but task is already holding lock: [ 80.006992][ T8472] ffffffff8c1f26e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 80.016449][ T8472] [ 80.016449][ T8472] which lock already depends on the new lock. [ 80.016449][ T8472] [ 80.026884][ T8472] [ 80.026884][ T8472] the existing dependency chain (in reverse order) is: [ 80.036005][ T8472] [ 80.036005][ T8472] -> #3 (major_names_lock){+.+.}-{3:3}: [ 80.043710][ T8472] __mutex_lock+0x12a/0x10a0 [ 80.048830][ T8472] __register_blkdev+0x2b/0x3e0 [ 80.054292][ T8472] register_mtd_blktrans+0x85/0x3c0 [ 80.059999][ T8472] do_one_initcall+0x103/0x650 [ 80.065283][ T8472] kernel_init_freeable+0x6b8/0x741 [ 80.070995][ T8472] kernel_init+0x1a/0x1d0 [ 80.075840][ T8472] ret_from_fork+0x1f/0x30 [ 80.080760][ T8472] [ 80.080760][ T8472] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 80.088377][ T8472] __mutex_lock+0x12a/0x10a0 [ 80.093471][ T8472] blktrans_open+0x69/0x600 [ 80.098487][ T8472] blkdev_get_whole+0xa1/0x420 [ 80.103777][ T8472] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 80.109838][ T8472] blkdev_open+0x295/0x300 [ 80.114755][ T8472] do_dentry_open+0x4c8/0x11d0 [ 80.120035][ T8472] path_openat+0x1c23/0x27f0 [ 80.125141][ T8472] do_filp_open+0x1aa/0x400 [ 80.130143][ T8472] do_sys_openat2+0x16d/0x420 [ 80.135330][ T8472] __x64_sys_open+0x119/0x1c0 [ 80.140510][ T8472] do_syscall_64+0x35/0xb0 [ 80.145437][ T8472] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 80.151927][ T8472] [ 80.151927][ T8472] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 80.159812][ T8472] __mutex_lock+0x12a/0x10a0 [ 80.164911][ T8472] del_gendisk+0x8b/0x770 [ 80.169743][ T8472] loop_control_ioctl+0x3b5/0x450 [ 80.175290][ T8472] __x64_sys_ioctl+0x193/0x200 [ 80.180557][ T8472] do_syscall_64+0x35/0xb0 [ 80.185476][ T8472] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 80.191968][ T8472] [ 80.191968][ T8472] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 80.199593][ T8472] __lock_acquire+0x2a07/0x54a0 [ 80.204943][ T8472] lock_acquire+0x1ab/0x510 [ 80.210032][ T8472] __mutex_lock+0x12a/0x10a0 [ 80.215124][ T8472] loop_add+0x9c/0x8c0 [ 80.219709][ T8472] loop_probe+0x6a/0x80 [ 80.224364][ T8472] blk_request_module+0x111/0x1d0 [ 80.229897][ T8472] blkdev_get_no_open+0x1d5/0x250 [ 80.235455][ T8472] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 80.241418][ T8472] blkdev_open+0x295/0x300 [ 80.246336][ T8472] do_dentry_open+0x4c8/0x11d0 [ 80.251602][ T8472] path_openat+0x1c23/0x27f0 [ 80.256707][ T8472] do_filp_open+0x1aa/0x400 [ 80.261708][ T8472] do_sys_openat2+0x16d/0x420 [ 80.266885][ T8472] __x64_sys_open+0x119/0x1c0 [ 80.272073][ T8472] do_syscall_64+0x35/0xb0 [ 80.277027][ T8472] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 80.283422][ T8472] [ 80.283422][ T8472] other info that might help us debug this: [ 80.283422][ T8472] [ 80.293639][ T8472] Chain exists of: [ 80.293639][ T8472] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 80.293639][ T8472] [ 80.306755][ T8472] Possible unsafe locking scenario: [ 80.306755][ T8472] [ 80.314179][ T8472] CPU0 CPU1 [ 80.319604][ T8472] ---- ---- [ 80.324953][ T8472] lock(major_names_lock); [ 80.329531][ T8472] lock(mtd_table_mutex); [ 80.336474][ T8472] lock(major_names_lock); [ 80.343576][ T8472] lock(loop_ctl_mutex); [ 80.347884][ T8472] [ 80.347884][ T8472] *** DEADLOCK *** [ 80.347884][ T8472] [ 80.356006][ T8472] 1 lock held by systemd-udevd/8472: [ 80.361286][ T8472] #0: ffffffff8c1f26e8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 80.371211][ T8472] [ 80.371211][ T8472] stack backtrace: [ 80.377078][ T8472] CPU: 0 PID: 8472 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 [ 80.385740][ T8472] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 80.396299][ T8472] Call Trace: [ 80.399696][ T8472] dump_stack_lvl+0xcd/0x134 [ 80.404496][ T8472] check_noncircular+0x25f/0x2e0 [ 80.409422][ T8472] ? print_circular_bug+0x1e0/0x1e0 [ 80.414650][ T8472] ? find_held_lock+0x2d/0x110 [ 80.419404][ T8472] ? lockdep_lock+0xc6/0x200 [ 80.423997][ T8472] ? call_rcu_zapped+0xb0/0xb0 [ 80.428747][ T8472] __lock_acquire+0x2a07/0x54a0 [ 80.433588][ T8472] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 80.439570][ T8472] lock_acquire+0x1ab/0x510 [ 80.444074][ T8472] ? loop_add+0x9c/0x8c0 [ 80.448302][ T8472] ? lock_release+0x720/0x720 [ 80.453069][ T8472] __mutex_lock+0x12a/0x10a0 [ 80.457647][ T8472] ? loop_add+0x9c/0x8c0 [ 80.461870][ T8472] ? loop_add+0x9c/0x8c0 [ 80.466180][ T8472] ? mutex_lock_io_nested+0xf00/0xf00 [ 80.471539][ T8472] ? rcu_read_lock_sched_held+0x3a/0x70 [ 80.477111][ T8472] ? trace_kmalloc+0x32/0xf0 [ 80.481695][ T8472] ? kmem_cache_alloc_trace+0x1fd/0x480 [ 80.487304][ T8472] loop_add+0x9c/0x8c0 [ 80.491357][ T8472] ? find_inode_fast+0x16f/0x220 [ 80.496328][ T8472] loop_probe+0x6a/0x80 [ 80.500503][ T8472] ? loop_add+0x8c0/0x8c0 [ 80.504809][ T8472] blk_request_module+0x111/0x1d0 [ 80.509833][ T8472] blkdev_get_no_open+0x1d5/0x250 [ 80.514846][ T8472] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 80.520382][ T8472] ? devcgroup_check_permission+0x1bb/0x410 [ 80.526346][ T8472] blkdev_open+0x295/0x300 [ 80.530771][ T8472] do_dentry_open+0x4c8/0x11d0 [ 80.535520][ T8472] ? blkdev_get_by_dev+0x80/0x80 [ 80.540442][ T8472] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 80.546693][ T8472] ? may_open+0x1f6/0x420 [ 80.551007][ T8472] path_openat+0x1c23/0x27f0 [ 80.555580][ T8472] ? path_lookupat+0x860/0x860 [ 80.560329][ T8472] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 80.566514][ T8472] do_filp_open+0x1aa/0x400 [ 80.571000][ T8472] ? may_open_dev+0xf0/0xf0 [ 80.575569][ T8472] ? rwlock_bug.part.0+0x90/0x90 [ 80.580489][ T8472] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 80.586813][ T8472] ? _find_next_bit+0x1e3/0x260 [ 80.591643][ T8472] ? _raw_spin_unlock+0x24/0x40 [ 80.596472][ T8472] ? alloc_fd+0x2f0/0x670 [ 80.600787][ T8472] do_sys_openat2+0x16d/0x420 [ 80.605483][ T8472] ? build_open_flags+0x6f0/0x6f0 [ 80.610488][ T8472] ? __context_tracking_exit+0xb8/0xe0 [ 80.615925][ T8472] __x64_sys_open+0x119/0x1c0 [ 80.620583][ T8472] ? do_sys_open+0x140/0x140 [ 80.625171][ T8472] ? __secure_computing+0x104/0x360 [ 80.630368][ T8472] do_syscall_64+0x35/0xb0 [ 80.634853][ T8472] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 80.640734][ T8472] RIP: 0033:0x7f0e12f5c840 [ 80.645311][ T8472] 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 [ 80.664897][ T8472] RSP: 002b:00007ffce4c363e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 80.673289][ T8472] RAX: ffffffffffffffda RBX: 000055bbec36cc00 RCX: 00007f0e12f5c840 [ 80.681237][ T8472] RDX: 000055bbea786fe3 RSI: 00000000000a0800 RDI: 000055bbec380050 [ 80.689199][ T8472] RBP: 00007ffce4c36560 R08: 000055bbea786670 R09: 0000000000000010 [ 80.697151][ T8472] R10: 000055bbea786d0c R11: 0000000000000246 R12: 00007ffce4c364b0 [ 80.705114][ T8472] R13: 000055bbec37fc00 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 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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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing 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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