Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.42' (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 syzkaller login: [ 73.344081][ T8577] [ 73.346443][ T8577] ====================================================== [ 73.353632][ T8577] WARNING: possible circular locking dependency detected [ 73.360822][ T8577] 5.14.0-rc5-syzkaller #0 Not tainted [ 73.366196][ T8577] ------------------------------------------------------ [ 73.373387][ T8577] systemd-udevd/8577 is trying to acquire lock: [ 73.379875][ T8577] ffffffff8c486b88 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_add+0x9c/0x8c0 [ 73.388779][ T8577] [ 73.388779][ T8577] but task is already holding lock: [ 73.396128][ T8577] ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 73.406130][ T8577] [ 73.406130][ T8577] which lock already depends on the new lock. [ 73.406130][ T8577] [ 73.417584][ T8577] [ 73.417584][ T8577] the existing dependency chain (in reverse order) is: [ 73.426688][ T8577] [ 73.426688][ T8577] -> #3 (major_names_lock){+.+.}-{3:3}: [ 73.434607][ T8577] __mutex_lock+0x12a/0x10a0 [ 73.439853][ T8577] __register_blkdev+0x2b/0x3e0 [ 73.445212][ T8577] register_mtd_blktrans+0x85/0x3c0 [ 73.451007][ T8577] do_one_initcall+0x103/0x650 [ 73.456581][ T8577] kernel_init_freeable+0x6b8/0x741 [ 73.462376][ T8577] kernel_init+0x1a/0x1d0 [ 73.467221][ T8577] ret_from_fork+0x1f/0x30 [ 73.472150][ T8577] [ 73.472150][ T8577] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 73.479784][ T8577] __mutex_lock+0x12a/0x10a0 [ 73.485069][ T8577] blktrans_open+0x69/0x600 [ 73.490111][ T8577] blkdev_get_whole+0xa1/0x420 [ 73.495590][ T8577] blkdev_get_by_dev.part.0+0x30c/0xdd0 [ 73.501667][ T8577] blkdev_open+0x295/0x300 [ 73.506881][ T8577] do_dentry_open+0x4c8/0x11d0 [ 73.512372][ T8577] path_openat+0x1c23/0x27f0 [ 73.517704][ T8577] do_filp_open+0x1aa/0x400 [ 73.522725][ T8577] do_sys_openat2+0x16d/0x420 [ 73.527920][ T8577] __x64_sys_open+0x119/0x1c0 [ 73.533209][ T8577] do_syscall_64+0x35/0xb0 [ 73.538688][ T8577] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.545186][ T8577] [ 73.545186][ T8577] -> #1 (&disk->open_mutex){+.+.}-{3:3}: [ 73.553080][ T8577] __mutex_lock+0x12a/0x10a0 [ 73.558275][ T8577] del_gendisk+0x8b/0x770 [ 73.563237][ T8577] loop_control_ioctl+0x3b5/0x450 [ 73.568869][ T8577] __do_compat_sys_ioctl+0x1c7/0x290 [ 73.574676][ T8577] __do_fast_syscall_32+0x65/0xf0 [ 73.580519][ T8577] do_fast_syscall_32+0x2f/0x70 [ 73.586307][ T8577] entry_SYSENTER_compat_after_hwframe+0x4d/0x5c [ 73.593169][ T8577] [ 73.593169][ T8577] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 73.600715][ T8577] __lock_acquire+0x2a07/0x54a0 [ 73.606093][ T8577] lock_acquire+0x1ab/0x510 [ 73.611277][ T8577] __mutex_lock+0x12a/0x10a0 [ 73.618301][ T8577] loop_add+0x9c/0x8c0 [ 73.622875][ T8577] loop_probe+0x6a/0x80 [ 73.627538][ T8577] blk_request_module+0x111/0x1d0 [ 73.633353][ T8577] blkdev_get_no_open+0x1d5/0x250 [ 73.638882][ T8577] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 73.644842][ T8577] blkdev_open+0x295/0x300 [ 73.650279][ T8577] do_dentry_open+0x4c8/0x11d0 [ 73.655805][ T8577] path_openat+0x1c23/0x27f0 [ 73.661078][ T8577] do_filp_open+0x1aa/0x400 [ 73.666097][ T8577] do_sys_openat2+0x16d/0x420 [ 73.671292][ T8577] __x64_sys_open+0x119/0x1c0 [ 73.676754][ T8577] do_syscall_64+0x35/0xb0 [ 73.681879][ T8577] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.688393][ T8577] [ 73.688393][ T8577] other info that might help us debug this: [ 73.688393][ T8577] [ 73.699018][ T8577] Chain exists of: [ 73.699018][ T8577] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 73.699018][ T8577] [ 73.712263][ T8577] Possible unsafe locking scenario: [ 73.712263][ T8577] [ 73.719913][ T8577] CPU0 CPU1 [ 73.725443][ T8577] ---- ---- [ 73.730793][ T8577] lock(major_names_lock); [ 73.735278][ T8577] lock(mtd_table_mutex); [ 73.742317][ T8577] lock(major_names_lock); [ 73.749669][ T8577] lock(loop_ctl_mutex); [ 73.754070][ T8577] [ 73.754070][ T8577] *** DEADLOCK *** [ 73.754070][ T8577] [ 73.762204][ T8577] 1 lock held by systemd-udevd/8577: [ 73.767479][ T8577] #0: ffffffff8c1f3fe8 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 73.777733][ T8577] [ 73.777733][ T8577] stack backtrace: [ 73.783775][ T8577] CPU: 1 PID: 8577 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0 [ 73.792341][ T8577] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.803002][ T8577] Call Trace: [ 73.806279][ T8577] dump_stack_lvl+0xcd/0x134 [ 73.810869][ T8577] check_noncircular+0x25f/0x2e0 [ 73.816181][ T8577] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.822169][ T8577] ? print_circular_bug+0x1e0/0x1e0 [ 73.827449][ T8577] ? lock_chain_count+0x20/0x20 [ 73.832458][ T8577] ? lockdep_lock+0xc6/0x200 [ 73.837055][ T8577] ? call_rcu_zapped+0xb0/0xb0 [ 73.842066][ T8577] __lock_acquire+0x2a07/0x54a0 [ 73.846991][ T8577] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.852970][ T8577] lock_acquire+0x1ab/0x510 [ 73.857484][ T8577] ? loop_add+0x9c/0x8c0 [ 73.861993][ T8577] ? lock_release+0x720/0x720 [ 73.867259][ T8577] ? path_openat+0x1c23/0x27f0 [ 73.872111][ T8577] ? do_filp_open+0x1aa/0x400 [ 73.877042][ T8577] ? do_sys_openat2+0x16d/0x420 [ 73.882055][ T8577] ? __x64_sys_open+0x119/0x1c0 [ 73.886895][ T8577] __mutex_lock+0x12a/0x10a0 [ 73.891569][ T8577] ? loop_add+0x9c/0x8c0 [ 73.895807][ T8577] ? loop_add+0x9c/0x8c0 [ 73.900140][ T8577] ? mutex_lock_io_nested+0xf00/0xf00 [ 73.905594][ T8577] ? rcu_read_lock_sched_held+0x3a/0x70 [ 73.911284][ T8577] loop_add+0x9c/0x8c0 [ 73.915348][ T8577] ? find_inode_fast+0x16f/0x220 [ 73.920376][ T8577] loop_probe+0x6a/0x80 [ 73.924623][ T8577] ? loop_add+0x8c0/0x8c0 [ 73.929120][ T8577] blk_request_module+0x111/0x1d0 [ 73.934492][ T8577] blkdev_get_no_open+0x1d5/0x250 [ 73.939818][ T8577] blkdev_get_by_dev.part.0+0x25/0xdd0 [ 73.945855][ T8577] ? devcgroup_check_permission+0x1bb/0x410 [ 73.952449][ T8577] blkdev_open+0x295/0x300 [ 73.956964][ T8577] do_dentry_open+0x4c8/0x11d0 [ 73.962337][ T8577] ? blkdev_get_by_dev+0x80/0x80 [ 73.967357][ T8577] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 73.973692][ T8577] ? may_open+0x1f6/0x420 [ 73.978208][ T8577] path_openat+0x1c23/0x27f0 [ 73.983064][ T8577] ? path_lookupat+0x860/0x860 [ 73.987820][ T8577] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 73.994055][ T8577] do_filp_open+0x1aa/0x400 [ 73.998940][ T8577] ? may_open_dev+0xf0/0xf0 [ 74.004744][ T8577] ? rwlock_bug.part.0+0x90/0x90 [ 74.010047][ T8577] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 74.016546][ T8577] ? _find_next_bit+0x1e3/0x260 [ 74.021523][ T8577] ? _raw_spin_unlock+0x24/0x40 [ 74.026459][ T8577] ? alloc_fd+0x2f0/0x670 [ 74.030786][ T8577] do_sys_openat2+0x16d/0x420 [ 74.035468][ T8577] ? build_open_flags+0x6f0/0x6f0 [ 74.040581][ T8577] ? __context_tracking_exit+0xb8/0xe0 [ 74.046039][ T8577] __x64_sys_open+0x119/0x1c0 [ 74.050725][ T8577] ? do_sys_open+0x140/0x140 [ 74.055390][ T8577] ? __secure_computing+0x104/0x360 [ 74.060606][ T8577] do_syscall_64+0x35/0xb0 [ 74.065112][ T8577] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 74.071084][ T8577] RIP: 0033:0x7fb64db4f840 [ 74.075493][ T8577] 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 [ 74.095171][ T8577] RSP: 002b:00007ffda711d248 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 74.103575][ T8577] RAX: ffffffffffffffda RBX: 0000560b556808f0 RCX: 00007fb64db4f840 [ 74.111962][ T8577] RDX: 0000560b5494bfe3 RSI: 00000000000a0800 RDI: 0000560b55680830 [ 74.120421][ T8577] RBP: 00007ffda711d3c0 R08: 0000560b5494b670 R09: 0000000000000010 [ 74.130103][ T8577] R10: 0000560b5494bd0c R11: 0000000000000246 R12: 00007ffda711d310 [ 74.138320][ T8577] R13: 0000560b55682010 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 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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 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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