Warning: Permanently added '10.128.0.250' (ED25519) to the list of known hosts. executing program [ 101.495828][ T5833] [ 101.498238][ T5833] ====================================================== [ 101.505265][ T5833] WARNING: possible circular locking dependency detected [ 101.512304][ T5833] 6.16.0-rc1-syzkaller-00003-gf09079bd04a9 #0 Not tainted [ 101.519423][ T5833] ------------------------------------------------------ [ 101.526464][ T5833] syz-executor394/5833 is trying to acquire lock: [ 101.532889][ T5833] ffffffff8e2666d0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_inc+0x12/0x30 [ 101.542476][ T5833] [ 101.542476][ T5833] but task is already holding lock: [ 101.549856][ T5833] ffff888025e229c8 (&q->rq_qos_mutex){+.+.}-{4:4}, at: wbt_init+0x393/0x540 [ 101.558606][ T5833] [ 101.558606][ T5833] which lock already depends on the new lock. [ 101.558606][ T5833] [ 101.569019][ T5833] [ 101.569019][ T5833] the existing dependency chain (in reverse order) is: [ 101.578040][ T5833] [ 101.578040][ T5833] -> #3 (&q->rq_qos_mutex){+.+.}-{4:4}: [ 101.585842][ T5833] __mutex_lock+0x199/0xb90 [ 101.590893][ T5833] wbt_init+0x393/0x540 [ 101.595590][ T5833] queue_wb_lat_store+0x354/0x3d0 [ 101.601163][ T5833] queue_attr_store+0x279/0x320 [ 101.606563][ T5833] sysfs_kf_write+0xf2/0x150 [ 101.611698][ T5833] kernfs_fop_write_iter+0x351/0x510 [ 101.617538][ T5833] vfs_write+0x6c4/0x1150 [ 101.622431][ T5833] ksys_write+0x12a/0x250 [ 101.627331][ T5833] do_syscall_64+0xcd/0x490 [ 101.632402][ T5833] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 101.638849][ T5833] [ 101.638849][ T5833] -> #2 (&q->q_usage_counter(io)#18){++++}-{0:0}: [ 101.647489][ T5833] blk_alloc_queue+0x619/0x760 [ 101.652816][ T5833] blk_mq_alloc_queue+0x175/0x290 [ 101.658405][ T5833] __blk_mq_alloc_disk+0x29/0x120 [ 101.663988][ T5833] loop_add+0x49e/0xb70 [ 101.668693][ T5833] loop_init+0x164/0x270 [ 101.673497][ T5833] do_one_initcall+0x120/0x6e0 [ 101.678843][ T5833] kernel_init_freeable+0x5c2/0x900 [ 101.684594][ T5833] kernel_init+0x1c/0x2b0 [ 101.689467][ T5833] ret_from_fork+0x5d4/0x6f0 [ 101.694602][ T5833] ret_from_fork_asm+0x1a/0x30 [ 101.699905][ T5833] [ 101.699905][ T5833] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 101.707143][ T5833] fs_reclaim_acquire+0x102/0x150 [ 101.712823][ T5833] __kmalloc_cache_node_noprof+0x53/0x420 [ 101.719106][ T5833] create_worker+0x10f/0x7e0 [ 101.724342][ T5833] workqueue_prepare_cpu+0xb5/0x160 [ 101.730436][ T5833] cpuhp_invoke_callback+0x3d5/0xa10 [ 101.736355][ T5833] __cpuhp_invoke_callback_range+0x101/0x210 [ 101.742965][ T5833] _cpu_up+0x3f5/0x930 [ 101.747574][ T5833] cpu_up+0x1dc/0x240 [ 101.752094][ T5833] cpuhp_bringup_mask+0xd8/0x210 [ 101.757610][ T5833] bringup_nonboot_cpus+0x176/0x1c0 [ 101.763382][ T5833] smp_init+0x34/0x160 [ 101.767989][ T5833] kernel_init_freeable+0x3a8/0x900 [ 101.773730][ T5833] kernel_init+0x1c/0x2b0 [ 101.778605][ T5833] ret_from_fork+0x5d4/0x6f0 [ 101.783743][ T5833] ret_from_fork_asm+0x1a/0x30 [ 101.789047][ T5833] [ 101.789047][ T5833] -> #0 (cpu_hotplug_lock){++++}-{0:0}: [ 101.796907][ T5833] __lock_acquire+0x126f/0x1c90 [ 101.802309][ T5833] lock_acquire+0x179/0x350 [ 101.807446][ T5833] cpus_read_lock+0x42/0x160 [ 101.812603][ T5833] static_key_slow_inc+0x12/0x30 [ 101.818091][ T5833] rq_qos_add+0x2f8/0x4b0 [ 101.823063][ T5833] wbt_init+0x3a9/0x540 [ 101.827774][ T5833] queue_wb_lat_store+0x354/0x3d0 [ 101.833378][ T5833] queue_attr_store+0x279/0x320 [ 101.838783][ T5833] sysfs_kf_write+0xf2/0x150 [ 101.843936][ T5833] kernfs_fop_write_iter+0x351/0x510 [ 101.849764][ T5833] vfs_write+0x6c4/0x1150 [ 101.854645][ T5833] ksys_write+0x12a/0x250 [ 101.859518][ T5833] do_syscall_64+0xcd/0x490 [ 101.864559][ T5833] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 101.870991][ T5833] [ 101.870991][ T5833] other info that might help us debug this: [ 101.870991][ T5833] [ 101.881231][ T5833] Chain exists of: [ 101.881231][ T5833] cpu_hotplug_lock --> &q->q_usage_counter(io)#18 --> &q->rq_qos_mutex [ 101.881231][ T5833] [ 101.895442][ T5833] Possible unsafe locking scenario: [ 101.895442][ T5833] [ 101.902992][ T5833] CPU0 CPU1 [ 101.908369][ T5833] ---- ---- [ 101.913743][ T5833] lock(&q->rq_qos_mutex); [ 101.918267][ T5833] lock(&q->q_usage_counter(io)#18); [ 101.926190][ T5833] lock(&q->rq_qos_mutex); [ 101.933232][ T5833] rlock(cpu_hotplug_lock); [ 101.937845][ T5833] [ 101.937845][ T5833] *** DEADLOCK *** [ 101.937845][ T5833] [ 101.945996][ T5833] 6 locks held by syz-executor394/5833: [ 101.952084][ T5833] #0: ffff888024bce428 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 [ 101.961117][ T5833] #1: ffff8880302fa888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x510 [ 101.970932][ T5833] #2: ffff8880233ff008 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2b2/0x510 [ 101.981003][ T5833] #3: ffff888025e227c8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 [ 101.992756][ T5833] #4: ffff888025e22800 (&q->q_usage_counter(queue)#20){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 [ 102.004741][ T5833] #5: ffff888025e229c8 (&q->rq_qos_mutex){+.+.}-{4:4}, at: wbt_init+0x393/0x540 [ 102.014125][ T5833] [ 102.014125][ T5833] stack backtrace: [ 102.020039][ T5833] CPU: 0 UID: 0 PID: 5833 Comm: syz-executor394 Not tainted 6.16.0-rc1-syzkaller-00003-gf09079bd04a9 #0 PREEMPT(full) [ 102.020070][ T5833] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 [ 102.020088][ T5833] Call Trace: [ 102.020100][ T5833] [ 102.020112][ T5833] dump_stack_lvl+0x116/0x1f0 [ 102.020156][ T5833] print_circular_bug+0x275/0x350 [ 102.020186][ T5833] check_noncircular+0x14c/0x170 [ 102.020217][ T5833] __lock_acquire+0x126f/0x1c90 [ 102.020252][ T5833] lock_acquire+0x179/0x350 [ 102.020281][ T5833] ? static_key_slow_inc+0x12/0x30 [ 102.020314][ T5833] ? __pfx___might_resched+0x10/0x10 [ 102.020340][ T5833] cpus_read_lock+0x42/0x160 [ 102.020363][ T5833] ? static_key_slow_inc+0x12/0x30 [ 102.020393][ T5833] static_key_slow_inc+0x12/0x30 [ 102.020423][ T5833] rq_qos_add+0x2f8/0x4b0 [ 102.020457][ T5833] wbt_init+0x3a9/0x540 [ 102.020482][ T5833] queue_wb_lat_store+0x354/0x3d0 [ 102.020519][ T5833] ? __pfx_queue_wb_lat_store+0x10/0x10 [ 102.020557][ T5833] ? __mutex_trylock_common+0xe9/0x250 [ 102.020588][ T5833] ? __pfx_queue_wb_lat_store+0x10/0x10 [ 102.020624][ T5833] queue_attr_store+0x279/0x320 [ 102.020661][ T5833] ? __pfx_queue_attr_store+0x10/0x10 [ 102.020696][ T5833] ? __lock_acquire+0x622/0x1c90 [ 102.020731][ T5833] ? find_held_lock+0x2b/0x80 [ 102.020752][ T5833] ? sysfs_file_kobj+0xe4/0x290 [ 102.020786][ T5833] ? __pfx_queue_attr_store+0x10/0x10 [ 102.020822][ T5833] sysfs_kf_write+0xf2/0x150 [ 102.020849][ T5833] kernfs_fop_write_iter+0x351/0x510 [ 102.020872][ T5833] ? __pfx_sysfs_kf_write+0x10/0x10 [ 102.020900][ T5833] vfs_write+0x6c4/0x1150 [ 102.020932][ T5833] ? __pfx_kernfs_fop_write_iter+0x10/0x10 [ 102.020958][ T5833] ? __pfx_vfs_write+0x10/0x10 [ 102.020991][ T5833] ? find_held_lock+0x2b/0x80 [ 102.021014][ T5833] ? find_held_lock+0x2b/0x80 [ 102.021036][ T5833] ksys_write+0x12a/0x250 [ 102.021067][ T5833] ? __pfx_ksys_write+0x10/0x10 [ 102.021103][ T5833] do_syscall_64+0xcd/0x490 [ 102.021124][ T5833] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 102.021148][ T5833] RIP: 0033:0x7fcf6ba15a79 [ 102.021175][ T5833] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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 b8 ff ff ff f7 d8 64 89 01 48 [ 102.021197][ T5833] RSP: 002b:00007ffd00a998b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 102.021218][ T5833] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf6ba15a79 [ 102.021233][ T5833] RDX: 0000000000000009 RSI: 00002000000001c0 RDI: 0000000000000003 [ 102.021247][ T5833] RBP: 00007fcf6ba885f0 R08: 0000000000000006 R09: 0000000000000006 [ 102.021262][ T5833] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 102.021275][ T5833] R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 [ 102.021296][ T5833] executing program [ 102.275220][ T43] cfg80211: failed to load regulatory.db executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program