[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.105' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 34.474274] BTRFS: device fsid 24c7a497-3402-47dd-bef8-82358f5f30e0 devid 1 transid 8 /dev/loop0 [ 34.489955] BTRFS info (device loop0): using free space tree [ 34.495860] BTRFS info (device loop0): has skinny extents [ 34.550323] [ 34.551966] ====================================================== [ 34.558262] WARNING: possible circular locking dependency detected [ 34.564566] 4.19.211-syzkaller #0 Not tainted [ 34.569034] ------------------------------------------------------ [ 34.575324] syz-executor313/8100 is trying to acquire lock: [ 34.581007] 000000000d7bde88 (&fs_info->qgroup_ioctl_lock){+.+.}, at: btrfs_del_qgroup_relation+0x45/0x70 [ 34.590701] [ 34.590701] but task is already holding lock: [ 34.596647] 000000001146e189 (sb_internal#2){.+.+}, at: start_transaction+0xa37/0xf90 [ 34.604603] [ 34.604603] which lock already depends on the new lock. [ 34.604603] [ 34.612892] [ 34.612892] the existing dependency chain (in reverse order) is: [ 34.620483] [ 34.620483] -> #1 (sb_internal#2){.+.+}: [ 34.626023] start_transaction+0xa37/0xf90 [ 34.630755] btrfs_quota_enable+0x169/0x10b0 [ 34.635661] btrfs_ioctl+0x622c/0x76d0 [ 34.640045] do_vfs_ioctl+0xcdb/0x12e0 [ 34.644430] ksys_ioctl+0x9b/0xc0 [ 34.648381] __x64_sys_ioctl+0x6f/0xb0 [ 34.652766] do_syscall_64+0xf9/0x620 [ 34.657089] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.662778] [ 34.662778] -> #0 (&fs_info->qgroup_ioctl_lock){+.+.}: [ 34.669519] __mutex_lock+0xd7/0x1190 [ 34.673820] btrfs_del_qgroup_relation+0x45/0x70 [ 34.679076] btrfs_ioctl+0x6004/0x76d0 [ 34.683462] do_vfs_ioctl+0xcdb/0x12e0 [ 34.687846] ksys_ioctl+0x9b/0xc0 [ 34.691798] __x64_sys_ioctl+0x6f/0xb0 [ 34.696189] do_syscall_64+0xf9/0x620 [ 34.700488] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.706168] [ 34.706168] other info that might help us debug this: [ 34.706168] [ 34.714288] Possible unsafe locking scenario: [ 34.714288] [ 34.720320] CPU0 CPU1 [ 34.724959] ---- ---- [ 34.729597] lock(sb_internal#2); [ 34.733110] lock(&fs_info->qgroup_ioctl_lock); [ 34.740357] lock(sb_internal#2); [ 34.746387] lock(&fs_info->qgroup_ioctl_lock); [ 34.751114] [ 34.751114] *** DEADLOCK *** [ 34.751114] [ 34.757153] 2 locks held by syz-executor313/8100: [ 34.761963] #0: 000000009d93883e (sb_writers#11){.+.+}, at: mnt_want_write_file+0x63/0x1d0 [ 34.770441] #1: 000000001146e189 (sb_internal#2){.+.+}, at: start_transaction+0xa37/0xf90 [ 34.778834] [ 34.778834] stack backtrace: [ 34.783312] CPU: 0 PID: 8100 Comm: syz-executor313 Not tainted 4.19.211-syzkaller #0 [ 34.791166] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 [ 34.800495] Call Trace: [ 34.803096] dump_stack+0x1fc/0x2ef [ 34.806704] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 34.812507] __lock_acquire+0x30c9/0x3ff0 [ 34.816640] ? mark_held_locks+0xf0/0xf0 [ 34.820700] ? mark_held_locks+0xf0/0xf0 [ 34.824739] ? do_syscall_64+0xf9/0x620 [ 34.828691] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.834036] lock_acquire+0x170/0x3c0 [ 34.837818] ? btrfs_del_qgroup_relation+0x45/0x70 [ 34.842727] ? btrfs_del_qgroup_relation+0x45/0x70 [ 34.847643] __mutex_lock+0xd7/0x1190 [ 34.851422] ? btrfs_del_qgroup_relation+0x45/0x70 [ 34.856334] ? lock_acquire+0x170/0x3c0 [ 34.860288] ? btrfs_del_qgroup_relation+0x45/0x70 [ 34.865210] ? mutex_trylock+0x1a0/0x1a0 [ 34.869260] ? do_raw_spin_unlock+0x171/0x230 [ 34.873734] ? _raw_spin_unlock+0x29/0x40 [ 34.877861] ? join_transaction+0x1b7/0xe20 [ 34.882164] ? btrfs_record_root_in_trans+0x13c/0x190 [ 34.887359] ? start_transaction+0x239/0xf90 [ 34.891749] btrfs_del_qgroup_relation+0x45/0x70 [ 34.896487] btrfs_ioctl+0x6004/0x76d0 [ 34.900448] ? is_bpf_text_address+0xfc/0x1b0 [ 34.904921] ? kernel_text_address+0xbd/0xf0 [ 34.909309] ? btrfs_ioctl_get_supported_features+0x50/0x50 [ 34.915001] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.920341] ? __save_stack_trace+0xaf/0x190 [ 34.924733] ? check_preemption_disabled+0x41/0x280 [ 34.929729] ? trace_hardirqs_off+0x64/0x200 [ 34.934117] ? __kasan_slab_free+0x186/0x1f0 [ 34.938557] ? kmem_cache_free+0x7f/0x260 [ 34.942685] ? putname+0xe1/0x120 [ 34.946116] ? do_sys_open+0x2ba/0x520 [ 34.949979] ? do_syscall_64+0xf9/0x620 [ 34.953928] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.959271] ? mark_held_locks+0xf0/0xf0 [ 34.963312] ? __lock_acquire+0x6de/0x3ff0 [ 34.967527] ? debug_check_no_obj_freed+0x201/0x490 [ 34.972527] ? lock_downgrade+0x720/0x720 [ 34.976689] ? lock_acquire+0x170/0x3c0 [ 34.980641] ? debug_check_no_obj_freed+0xb5/0x490 [ 34.985549] ? btrfs_ioctl_get_supported_features+0x50/0x50 [ 34.991235] do_vfs_ioctl+0xcdb/0x12e0 [ 34.995341] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 35.000431] ? debug_check_no_obj_freed+0x201/0x490 [ 35.005435] ? ioctl_preallocate+0x200/0x200 [ 35.009828] ? putname+0xe1/0x120 [ 35.013261] ? putname+0xe1/0x120 [ 35.016689] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 35.021683] ? kmem_cache_free+0x226/0x260 [ 35.025999] ? putname+0xe1/0x120 [ 35.029435] ? do_sys_open+0x2bf/0x520 [ 35.033297] ? filp_open+0x70/0x70 [ 35.036815] ksys_ioctl+0x9b/0xc0 [ 35.040246] __x64_sys_ioctl+0x6f/0xb0 [ 35.044112] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 35.048669] do_syscall_64+0xf9/0x620 [ 35.052450] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 35.057623] RIP: 0033:0x7f26b4e08af9 [ 35.061314] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 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 [ 35.080195] RSP: 002b:00007ffe1000e338 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 35.087964] RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f26b4e08af9 [ 35.095209] RDX: 0000000020000e80 RSI: 0000000040189429 RDI: 0000000000000005 [ 3