Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.91' (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 syzkaller login: [ 73.627730][ T8542] [ 73.630110][ T8542] ====================================================== [ 73.637333][ T8542] WARNING: possible circular locking dependency detected [ 73.644675][ T8542] 5.13.0-rc7-syzkaller #0 Not tainted [ 73.650034][ T8542] ------------------------------------------------------ [ 73.657044][ T8542] systemd-udevd/8542 is trying to acquire lock: [ 73.663358][ T8542] ffffffff8ca6de28 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_probe+0xc7/0x150 [ 73.672081][ T8542] [ 73.672081][ T8542] but task is already holding lock: [ 73.679434][ T8542] ffffffff8c7e0368 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 73.688925][ T8542] [ 73.688925][ T8542] which lock already depends on the new lock. [ 73.688925][ T8542] [ 73.699318][ T8542] [ 73.699318][ T8542] the existing dependency chain (in reverse order) is: [ 73.708328][ T8542] [ 73.708328][ T8542] -> #3 (major_names_lock){+.+.}-{3:3}: [ 73.716053][ T8542] __mutex_lock+0x139/0x10c0 [ 73.721198][ T8542] __register_blkdev+0x2b/0x3e0 [ 73.726571][ T8542] register_mtd_blktrans+0x85/0x3c0 [ 73.732323][ T8542] do_one_initcall+0x103/0x650 [ 73.737609][ T8542] kernel_init_freeable+0x6c4/0x74d [ 73.743351][ T8542] kernel_init+0xd/0x1b8 [ 73.748132][ T8542] ret_from_fork+0x1f/0x30 [ 73.753087][ T8542] [ 73.753087][ T8542] -> #2 (mtd_table_mutex){+.+.}-{3:3}: [ 73.760769][ T8542] __mutex_lock+0x139/0x10c0 [ 73.765901][ T8542] blktrans_open+0x69/0x600 [ 73.770957][ T8542] __blkdev_get+0x182/0xa30 [ 73.776010][ T8542] blkdev_get_by_dev+0x200/0x660 [ 73.781502][ T8542] blkdev_open+0x154/0x2b0 [ 73.786486][ T8542] do_dentry_open+0x4b9/0x11b0 [ 73.791802][ T8542] path_openat+0x1c0e/0x27e0 [ 73.796939][ T8542] do_filp_open+0x190/0x3d0 [ 73.801993][ T8542] do_sys_openat2+0x16d/0x420 [ 73.807211][ T8542] __x64_sys_open+0x119/0x1c0 [ 73.812518][ T8542] do_syscall_64+0x3a/0xb0 [ 73.817740][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.824790][ T8542] [ 73.824790][ T8542] -> #1 (&bdev->bd_mutex){+.+.}-{3:3}: [ 73.832462][ T8542] __mutex_lock+0x139/0x10c0 [ 73.837602][ T8542] del_gendisk+0x24b/0xa00 [ 73.842575][ T8542] loop_control_ioctl+0x3e7/0x4c0 [ 73.848151][ T8542] __x64_sys_ioctl+0x193/0x200 [ 73.853468][ T8542] do_syscall_64+0x3a/0xb0 [ 73.858429][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.864869][ T8542] [ 73.864869][ T8542] -> #0 (loop_ctl_mutex){+.+.}-{3:3}: [ 73.872453][ T8542] __lock_acquire+0x2a17/0x5230 [ 73.877853][ T8542] lock_acquire+0x1ab/0x740 [ 73.882909][ T8542] __mutex_lock+0x139/0x10c0 [ 73.888143][ T8542] loop_probe+0xc7/0x150 [ 73.892960][ T8542] blk_request_module+0x111/0x1d0 [ 73.898529][ T8542] blkdev_get_no_open+0x1d8/0x250 [ 73.904111][ T8542] blkdev_get_by_dev+0x76/0x660 [ 73.909509][ T8542] blkdev_open+0x154/0x2b0 [ 73.914468][ T8542] do_dentry_open+0x4b9/0x11b0 [ 73.919775][ T8542] path_openat+0x1c0e/0x27e0 [ 73.924929][ T8542] do_filp_open+0x190/0x3d0 [ 73.929976][ T8542] do_sys_openat2+0x16d/0x420 [ 73.935201][ T8542] __x64_sys_open+0x119/0x1c0 [ 73.940412][ T8542] do_syscall_64+0x3a/0xb0 [ 73.945373][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 73.951812][ T8542] [ 73.951812][ T8542] other info that might help us debug this: [ 73.951812][ T8542] [ 73.962047][ T8542] Chain exists of: [ 73.962047][ T8542] loop_ctl_mutex --> mtd_table_mutex --> major_names_lock [ 73.962047][ T8542] [ 73.975099][ T8542] Possible unsafe locking scenario: [ 73.975099][ T8542] [ 73.982833][ T8542] CPU0 CPU1 [ 73.988204][ T8542] ---- ---- [ 73.993575][ T8542] lock(major_names_lock); [ 73.998198][ T8542] lock(mtd_table_mutex); [ 74.005150][ T8542] lock(major_names_lock); [ 74.012195][ T8542] lock(loop_ctl_mutex); [ 74.016538][ T8542] [ 74.016538][ T8542] *** DEADLOCK *** [ 74.016538][ T8542] [ 74.024777][ T8542] 1 lock held by systemd-udevd/8542: [ 74.030073][ T8542] #0: ffffffff8c7e0368 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 [ 74.040031][ T8542] [ 74.040031][ T8542] stack backtrace: [ 74.045948][ T8542] CPU: 1 PID: 8542 Comm: systemd-udevd Not tainted 5.13.0-rc7-syzkaller #0 [ 74.054552][ T8542] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 74.064626][ T8542] Call Trace: [ 74.067919][ T8542] dump_stack+0x141/0x1d7 [ 74.072269][ T8542] check_noncircular+0x25f/0x2e0 [ 74.077346][ T8542] ? pv_hash+0x100/0x100 [ 74.081612][ T8542] ? print_circular_bug+0x1e0/0x1e0 [ 74.086834][ T8542] ? mark_lock+0xef/0x17b0 [ 74.091280][ T8542] ? lockdep_lock+0x1b7/0x200 [ 74.095981][ T8542] ? call_rcu_zapped+0xb0/0xb0 [ 74.100777][ T8542] ? tomoyo_check_open_permission+0x172/0x380 [ 74.106870][ T8542] ? security_file_open+0x52/0x4f0 [ 74.112020][ T8542] __lock_acquire+0x2a17/0x5230 [ 74.116909][ T8542] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 74.122939][ T8542] lock_acquire+0x1ab/0x740 [ 74.127470][ T8542] ? loop_probe+0xc7/0x150 [ 74.131917][ T8542] ? lock_release+0x720/0x720 [ 74.136647][ T8542] __mutex_lock+0x139/0x10c0 [ 74.141267][ T8542] ? loop_probe+0xc7/0x150 [ 74.145717][ T8542] ? loop_probe+0xc7/0x150 [ 74.150185][ T8542] ? mutex_lock_io_nested+0xf20/0xf20 [ 74.155592][ T8542] ? __mutex_lock+0x5d5/0x10c0 [ 74.160408][ T8542] ? blk_request_module+0x25/0x1d0 [ 74.165565][ T8542] ? find_held_lock+0x2d/0x110 [ 74.170360][ T8542] ? mutex_lock_io_nested+0xf20/0xf20 [ 74.175764][ T8542] ? ilookup+0xb3/0x230 [ 74.180035][ T8542] loop_probe+0xc7/0x150 [ 74.184343][ T8542] ? loop_control_ioctl+0x4c0/0x4c0 [ 74.189651][ T8542] ? find_inode_fast+0x16f/0x220 [ 74.194701][ T8542] ? do_raw_spin_unlock+0x171/0x230 [ 74.199932][ T8542] ? loop_control_ioctl+0x4c0/0x4c0 [ 74.205161][ T8542] blk_request_module+0x111/0x1d0 [ 74.210221][ T8542] blkdev_get_no_open+0x1d8/0x250 [ 74.215279][ T8542] blkdev_get_by_dev+0x76/0x660 [ 74.220158][ T8542] blkdev_open+0x154/0x2b0 [ 74.224608][ T8542] do_dentry_open+0x4b9/0x11b0 [ 74.229404][ T8542] ? blkdev_get_by_dev+0x660/0x660 [ 74.234568][ T8542] ? may_open+0x1f6/0x420 [ 74.238939][ T8542] path_openat+0x1c0e/0x27e0 [ 74.243558][ T8542] ? path_lookupat+0x850/0x850 [ 74.248405][ T8542] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 74.254432][ T8542] do_filp_open+0x190/0x3d0 [ 74.258974][ T8542] ? may_open_dev+0xf0/0xf0 [ 74.263510][ T8542] ? do_raw_spin_lock+0x120/0x2b0 [ 74.268566][ T8542] ? rwlock_bug.part.0+0x90/0x90 [ 74.273529][ T8542] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 74.279821][ T8542] ? _find_next_bit+0x1e3/0x260 [ 74.284872][ T8542] ? _raw_spin_unlock+0x24/0x40 [ 74.289746][ T8542] ? alloc_fd+0x2e6/0x660 [ 74.294119][ T8542] do_sys_openat2+0x16d/0x420 [ 74.298855][ T8542] ? build_open_flags+0x6f0/0x6f0 [ 74.303911][ T8542] ? __context_tracking_exit+0xb8/0xe0 [ 74.309485][ T8542] __x64_sys_open+0x119/0x1c0 [ 74.314210][ T8542] ? do_sys_open+0x140/0x140 [ 74.318838][ T8542] ? __secure_computing+0x104/0x360 [ 74.324238][ T8542] do_syscall_64+0x3a/0xb0 [ 74.328701][ T8542] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 74.334633][ T8542] RIP: 0033:0x7faae8826840 [ 74.339073][ 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 [ 74.358908][ T8542] RSP: 002b:00007ffc2b389318 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 74.367430][ T8542] RAX: ffffffffffffffda RBX: 00005643522d0810 RCX: 00007faae8826840 executing program [ 74.375426][ T8542] RDX: 0000564350b49fe3 RSI: 00000000000a0800 RDI: 00005643522d51d0 [ 74.384064][ T8542] RBP: 00007ffc2b389490 R08: 0000564350b49670 R09: 0000000000000010 [ 74.392057][ T8542] R10: 0000564350b49d0c R11: 0000000000000246 R12: 00007ffc2b3893e0 [ 74.400065][ T8542] R13: 00005643522d6060 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 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