[ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.22' (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 syzkaller login: [ 77.177137][ T8571] [ 77.179494][ T8571] ====================================================== [ 77.186512][ T8571] WARNING: possible circular locking dependency detected [ 77.193521][ T8571] 5.14.0-rc5-syzkaller #0 Not tainted [ 77.198875][ T8571] ------------------------------------------------------ [ 77.205869][ T8571] systemd-udevd/8571 is trying to acquire lock: [ 77.212087][ T8571] ffffffff8c487968 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 77.220536][ T8571] [ 77.220536][ T8571] but task is already holding lock: [ 77.227877][ T8571] ffffffff8c1f3f08 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 77.237370][ T8571] [ 77.237370][ T8571] which lock already depends on the new lock. [ 77.237370][ T8571] [ 77.247756][ T8571] [ 77.247756][ T8571] the existing dependency chain (in reverse order) is: [ 77.256857][ T8571] [ 77.256857][ T8571] -> #3 (major_names_lock){+.+.}-{3:3}: [ 77.264568][ T8571] __mutex_lock+0x12a/0x10a0 [ 77.269682][ T8571] __register_blkdev+0x2b/0x3e0 [ 77.275048][ T8571] register_mtd_blktrans+0x85/0x3c0 [ 77.280927][ T8571] do_one_initcall+0x103/0x650 [ 77.286204][ T8571] kernel_init_freeable+0x6b8/0x741 [ 77.291912][ T8571] kernel_init+0x1a/0x1d0 [ 77.296861][ T8571] ret_from_fork+0x1f/0x30 [ 77.301785][ T8571] [ 77.301785][ T8571] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 77.309672][ T8571] __mutex_lock+0x12a/0x10a0 [ 77.314792][ T8571] blktrans_open+0x69/0x600 [ 77.319801][ T8571] blkdev_get_whole+0xa1/0x420 [ 77.325070][ T8571] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 77.331118][ T8571] blkdev_open+0x295/0x300 [ 77.336043][ T8571] do_dentry_open+0x4c8/0x11d0 [ 77.341317][ T8571] path_openat+0x1c23/0x27f0 [ 77.346419][ T8571] do_filp_open+0x1aa/0x400 [ 77.351426][ T8571] do_sys_openat2+0x16d/0x420 [ 77.356607][ T8571] __x64_sys_open+0x119/0x1c0 [ 77.361789][ T8571] do_syscall_64+0x35/0xb0 [ 77.366730][ T8571] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.373138][ T8571] [ 77.373138][ T8571] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 77.380941][ T8571] __mutex_lock+0x12a/0x10a0 [ 77.386037][ T8571] del_gendisk+0x8b/0x770 [ 77.390874][ T8571] loop_control_ioctl+0x3b5/0x450 [ 77.396403][ T8571] __do_compat_sys_ioctl+0x1c7/0x290 [ 77.402194][ T8571] __do_fast_syscall_32+0x65/0xf0 [ 77.407725][ T8571] do_fast_syscall_32+0x2f/0x70 [ 77.413126][ T8571] entry_SYSENTER_compat_after_hwframe+0x4d/0x5c [ 77.419957][ T8571] [ 77.419957][ T8571] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 77.427509][ T8571] __lock_acquire+0x2a07/0x54a0 [ 77.432865][ T8571] lock_acquire+0x1ab/0x510 [ 77.437871][ T8571] __mutex_lock+0x12a/0x10a0 [ 77.442970][ T8571] loop_add+0x9c/0x8c0 [ 77.447541][ T8571] loop_probe+0x6a/0x80 [ 77.452200][ T8571] blk_request_module+0x111/0x1d0 [ 77.457736][ T8571] blkdev_get_no_open+0x1d5/0x250 [ 77.463280][ T8571] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 77.469242][ T8571] blkdev_open+0x295/0x300 [ 77.474164][ T8571] do_dentry_open+0x4c8/0x11d0 [ 77.479432][ T8571] path_openat+0x1c23/0x27f0 [ 77.484525][ T8571] do_filp_open+0x1aa/0x400 [ 77.489532][ T8571] do_sys_openat2+0x16d/0x420 [ 77.494714][ T8571] __x64_sys_open+0x119/0x1c0 [ 77.499896][ T8571] do_syscall_64+0x35/0xb0 [ 77.504829][ T8571] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.511224][ T8571] [ 77.511224][ T8571] other info that might help us debug this: [ 77.511224][ T8571] [ 77.521429][ T8571] Chain exists of: [ 77.521429][ T8571] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 77.521429][ T8571] [ 77.534434][ T8571] Possible unsafe locking scenario: [ 77.534434][ T8571] [ 77.541863][ T8571] CPU0 CPU1 [ 77.547209][ T8571] ---- ---- [ 77.552573][ T8571] lock(major_names_lock); [ 77.557056][ T8571] lock(mtd_table_mutex); [ 77.564060][ T8571] lock(major_names_lock); [ 77.571075][ T8571] lock(loop_ctl_mutex); [ 77.575389][ T8571] [ 77.575389][ T8571] *** DEADLOCK *** [ 77.575389][ T8571] [ 77.583656][ T8571] 1 lock held by systemd-udevd/8571: [ 77.588922][ T8571] #0: ffffffff8c1f3f08 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 77.598823][ T8571] [ 77.598823][ T8571] stack backtrace: [ 77.604687][ T8571] CPU: 1 PID: 8571 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 [ 77.613255][ T8571] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 77.623294][ T8571] Call Trace: [ 77.626568][ T8571] dump_stack_lvl+0xcd/0x134 [ 77.631163][ T8571] check_noncircular+0x25f/0x2e0 [ 77.636086][ T8571] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 77.642056][ T8571] ? print_circular_bug+0x1e0/0x1e0 [ 77.647358][ T8571] ? lock_chain_count+0x20/0x20 [ 77.652209][ T8571] ? lockdep_lock+0xc6/0x200 [ 77.656792][ T8571] ? call_rcu_zapped+0xb0/0xb0 [ 77.661544][ T8571] __lock_acquire+0x2a07/0x54a0 [ 77.666392][ T8571] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 77.672373][ T8571] lock_acquire+0x1ab/0x510 [ 77.676863][ T8571] ? loop_add+0x9c/0x8c0 [ 77.681095][ T8571] ? lock_release+0x720/0x720 [ 77.685755][ T8571] ? path_openat+0x1c23/0x27f0 [ 77.690520][ T8571] ? do_filp_open+0x1aa/0x400 [ 77.695179][ T8571] ? do_sys_openat2+0x16d/0x420 [ 77.700016][ T8571] ? __x64_sys_open+0x119/0x1c0 [ 77.704863][ T8571] __mutex_lock+0x12a/0x10a0 [ 77.709438][ T8571] ? loop_add+0x9c/0x8c0 [ 77.713665][ T8571] ? loop_add+0x9c/0x8c0 [ 77.717892][ T8571] ? mutex_lock_io_nested+0xf00/0xf00 [ 77.723250][ T8571] ? rcu_read_lock_sched_held+0x3a/0x70 [ 77.728803][ T8571] loop_add+0x9c/0x8c0 [ 77.732857][ T8571] ? find_inode_fast+0x16f/0x220 [ 77.737805][ T8571] loop_probe+0x6a/0x80 [ 77.741970][ T8571] ? loop_add+0x8c0/0x8c0 [ 77.746294][ T8571] blk_request_module+0x111/0x1d0 [ 77.751315][ T8571] blkdev_get_no_open+0x1d5/0x250 [ 77.756385][ T8571] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 77.762095][ T8571] ? devcgroup_check_permission+0x1bb/0x410 [ 77.768070][ T8571] blkdev_open+0x295/0x300 [ 77.772480][ T8571] do_dentry_open+0x4c8/0x11d0 [ 77.777230][ T8571] ? blkdev_get_by_dev+0x80/0x80 [ 77.782152][ T8571] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 77.788376][ T8571] ? may_open+0x1f6/0x420 [ 77.792692][ T8571] path_openat+0x1c23/0x27f0 [ 77.797268][ T8571] ? path_lookupat+0x860/0x860 [ 77.802081][ T8571] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 77.808056][ T8571] do_filp_open+0x1aa/0x400 [ 77.812554][ T8571] ? may_open_dev+0xf0/0xf0 [ 77.817058][ T8571] ? rwlock_bug.part.0+0x90/0x90 [ 77.821982][ T8571] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 77.828208][ T8571] ? _find_next_bit+0x1e3/0x260 [ 77.833070][ T8571] ? _raw_spin_unlock+0x24/0x40 [ 77.838013][ T8571] ? alloc_fd+0x2f0/0x670 [ 77.842333][ T8571] do_sys_openat2+0x16d/0x420 [ 77.847005][ T8571] ? build_open_flags+0x6f0/0x6f0 [ 77.852020][ T8571] ? __context_tracking_exit+0xb8/0xe0 [ 77.857477][ T8571] __x64_sys_open+0x119/0x1c0 [ 77.862161][ T8571] ? do_sys_open+0x140/0x140 [ 77.866739][ T8571] ? __secure_computing+0x104/0x360 [ 77.871924][ T8571] do_syscall_64+0x35/0xb0 [ 77.876334][ T8571] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 77.882211][ T8571] RIP: 0033:0x7fbfe07ca840 [ 77.886607][ T8571] 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 [ 77.906212][ T8571] RSP: 002b:00007ffeeb2833b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 77.914610][ T8571] RAX: ffffffffffffffda RBX: 0000559b621a48f0 RCX: 00007fbfe07ca840 [ 77.922578][ T8571] RDX: 0000559b602affe3 RSI: 00000000000a0800 RDI: 0000559b621a4830 executing program executing program [ 77.930532][ T8571] RBP: 00007ffeeb283530 R08: 0000559b602af670 R09: 0000000000000010 [ 77.938484][ T8571] R10: 0000559b602afd0c R11: 0000000000000246 R12: 00007ffeeb283480 [ 77.946437][ T8571] R13: 0000559b621a6010 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