Warning: Permanently added '10.128.0.89' (ECDSA) to the list of known hosts. [ 79.173528][ T8445] [ 79.178012][ T8445] ====================================================== [ 79.185704][ T8445] WARNING: possible circular locking dependency detected [ 79.194136][ T8445] 5.13.0-rc4-syzkaller #0 Not tainted [ 79.199949][ T8445] ------------------------------------------------------ [ 79.209025][ T8445] syz-executor615/8445 is trying to acquire lock: [ 79.216169][ T8445] ffff88801d872320 (&bdev->bd_mutex){+.+.}-{3:3}, at: del_gendisk+0x24b/0xa00 [ 79.225789][ T8445] [ 79.225789][ T8445] but task is already holding lock: [ 79.233801][ T8445] ffffffff8ca6d9a8 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_control_ioctl+0x7b/0x4f0 [ 79.243940][ T8445] [ 79.243940][ T8445] which lock already depends on the new lock. [ 79.243940][ T8445] [ 79.255206][ T8445] [ 79.255206][ T8445] the existing dependency chain (in reverse order) is: [ 79.265250][ T8445] [ 79.265250][ T8445] -> #1 (loop_ctl_mutex){+.+.}-{3:3}: [ 79.273124][ T8445] __mutex_lock+0x139/0x10c0 [ 79.278559][ T8445] lo_open+0x1a/0x130 [ 79.284360][ T8445] __blkdev_get+0x182/0xa30 [ 79.290262][ T8445] blkdev_get_by_dev+0x200/0x660 [ 79.296642][ T8445] blkdev_open+0x154/0x2b0 [ 79.301778][ T8445] do_dentry_open+0x4b9/0x11b0 [ 79.307885][ T8445] path_openat+0x1c0e/0x27e0 [ 79.313371][ T8445] do_filp_open+0x190/0x3d0 [ 79.318888][ T8445] do_sys_openat2+0x16d/0x420 [ 79.324555][ T8445] __x64_sys_open+0x119/0x1c0 [ 79.330228][ T8445] do_syscall_64+0x3a/0xb0 [ 79.335654][ T8445] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 79.342229][ T8445] [ 79.342229][ T8445] -> #0 (&bdev->bd_mutex){+.+.}-{3:3}: [ 79.351448][ T8445] __lock_acquire+0x2a17/0x5230 [ 79.356966][ T8445] lock_acquire+0x1ab/0x740 [ 79.362355][ T8445] __mutex_lock+0x139/0x10c0 [ 79.367919][ T8445] del_gendisk+0x24b/0xa00 [ 79.373754][ T8445] loop_control_ioctl+0x40d/0x4f0 [ 79.379805][ T8445] __x64_sys_ioctl+0x193/0x200 [ 79.385242][ T8445] do_syscall_64+0x3a/0xb0 [ 79.391098][ T8445] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 79.399128][ T8445] [ 79.399128][ T8445] other info that might help us debug this: [ 79.399128][ T8445] [ 79.410578][ T8445] Possible unsafe locking scenario: [ 79.410578][ T8445] [ 79.419185][ T8445] CPU0 CPU1 [ 79.425109][ T8445] ---- ---- [ 79.431648][ T8445] lock(loop_ctl_mutex); [ 79.436681][ T8445] lock(&bdev->bd_mutex); [ 79.445588][ T8445] lock(loop_ctl_mutex); [ 79.454357][ T8445] lock(&bdev->bd_mutex); [ 79.459183][ T8445] [ 79.459183][ T8445] *** DEADLOCK *** [ 79.459183][ T8445] [ 79.468464][ T8445] 1 lock held by syz-executor615/8445: [ 79.474327][ T8445] #0: ffffffff8ca6d9a8 (loop_ctl_mutex){+.+.}-{3:3}, at: loop_control_ioctl+0x7b/0x4f0 [ 79.485362][ T8445] [ 79.485362][ T8445] stack backtrace: [ 79.491996][ T8445] CPU: 0 PID: 8445 Comm: syz-executor615 Not tainted 5.13.0-rc4-syzkaller #0 [ 79.502444][ T8445] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 79.515020][ T8445] Call Trace: [ 79.519142][ T8445] dump_stack+0x141/0x1d7 [ 79.523789][ T8445] check_noncircular+0x25f/0x2e0 [ 79.529551][ T8445] ? print_circular_bug+0x1e0/0x1e0 [ 79.535745][ T8445] ? lockdep_lock+0xc6/0x200 [ 79.540609][ T8445] ? call_rcu_zapped+0xb0/0xb0 [ 79.545567][ T8445] ? mark_held_locks+0x9f/0xe0 [ 79.550940][ T8445] __lock_acquire+0x2a17/0x5230 [ 79.556274][ T8445] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 79.563222][ T8445] lock_acquire+0x1ab/0x740 [ 79.568549][ T8445] ? del_gendisk+0x24b/0xa00 [ 79.573926][ T8445] ? lock_release+0x720/0x720 [ 79.579489][ T8445] ? find_held_lock+0x2d/0x110 [ 79.584849][ T8445] __mutex_lock+0x139/0x10c0 [ 79.590668][ T8445] ? del_gendisk+0x24b/0xa00 [ 79.595722][ T8445] ? mutex_lock_io_nested+0xf20/0xf20 [ 79.601571][ T8445] ? del_gendisk+0x24b/0xa00 [ 79.606623][ T8445] ? __mutex_unlock_slowpath+0xe2/0x610 [ 79.612554][ T8445] ? mutex_lock_io_nested+0xf20/0xf20 [ 79.618677][ T8445] ? wait_for_completion_io+0x270/0x270 [ 79.625162][ T8445] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 79.631813][ T8445] ? kernfs_remove_by_name_ns+0x62/0xb0 [ 79.637946][ T8445] ? sysfs_remove_files+0x87/0xf0 [ 79.644334][ T8445] del_gendisk+0x24b/0xa00 [ 79.649429][ T8445] loop_control_ioctl+0x40d/0x4f0 [ 79.654750][ T8445] ? loop_lookup+0x1d0/0x1d0 [ 79.660450][ T8445] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 79.666893][ T8445] ? loop_lookup+0x1d0/0x1d0 [ 79.672315][ T8445] __x64_sys_ioctl+0x193/0x200 [ 79.678342][ T8445] do_syscall_64+0x3a/0xb0 [ 79.683301][ T8445] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 79.689733][ T8445] RIP: 0033:0x43ee49 [ 79.693844][ T8445] Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 [ 79.715979][ T8445] RSP: 002b:00007ffd20f0ed48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 executing program [ 79.726310][ T8445] RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ee49 [ 79.736085][ T8445] RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 [ 79.744588][ T8445] RBP: 0000000000402e30 R08: 0000000000000000 R09: 0000000000400488 [ 79.753119][ T8445] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402ec0 [ 79.762032][ T8445] R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488