program: syz_mount_image$squashfs(&(0x7f0000000040), &(0x7f0000000240)='./file2\x00', 0x800, &(0x7f0000000300)=ANY=[], 0x9, 0x1d7, &(0x7f0000000b00)="$eJzKKC4sZmdgYPj7sSaZQYABDBgZeBguMDAysDAwMKgzQsQYmCDUeij/BZSeCZW2gfIFGMEGMCyE8ituaa9bc8rvzElPXa1lsswMrZ7a8shicqk9Rm6Si3kkmBlCU48sKq6syk7MyUktKmZhqLjFuOF04AkGluv211SaJTgd/shzOCRpOugwHfHxyJrRWMI5SUpTjI0tU+HsmesMDAwaRxgerWDeWOeZ11hXmDo1Ly0vqSqrKmvexIkbZzZ2NjaunFgXlea3irElxWVTUycjk8MWNTYGZkP1STbaE961r3qY5MDa4+HXvJ+BgSGV+ZLxwiKpUyuqZk74ovSH0fA7wx2eshUSGhpOElckLBpMGI7UsTe4MlTcSk5pYEhTCGNMUmMTa9tyZk4IMz+b2wJQiDKFHuVYOlPC4oBQ1cmflppvHRLdZmx76sB2hufwcZ41BX1MDMclGJwWCv6XARmT0NBQprGWaantgi9FGn8lvDgZnDIY3O2ZljVDA5KlAUSuhPJkwXoSkld46GhqGqUkJzRsiv3CwFBgqMywdQ/naoEGiLL/////Z2BQYWBg2M4Ii1sIuAZjjIJRMApGwSgYBaNgFIyCUTAKRsEoGBEAEAAA//+BlZYF") r0 = syz_open_procfs(0x0, &(0x7f0000000240)='net/vlan/vlan0\x00') preadv(r0, &(0x7f00000004c0)=[{&(0x7f0000000000)=""/216, 0xd8}], 0x1, 0xa3, 0xd) mkdirat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000)='./cgroup.net/syz1\x00', 0x1ff) r1 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0) r2 = openat$cgroup_int(r1, &(0x7f00000002c0)='blkio.throttle.write_iops_device\x00', 0x2, 0x0) write$cgroup_subtree(r2, &(0x7f00000000c0)=ANY=[], 0x6a) (fail_nth: 4) [ 147.133935][ T4662] Bluetooth: hci0: command tx timeout [ 147.249386][ T5333] loop0: detected capacity change from 0 to 8 [ 147.335097][ T5333] SQUASHFS error: zlib decompression failed, data probably corrupt [ 147.344485][ T5333] SQUASHFS error: Failed to read block 0x9b: -5 [ 147.347156][ T5333] SQUASHFS error: Unable to read metadata cache entry [99] [ 147.350110][ T5333] SQUASHFS error: Unable to read inode 0x127 [ 147.438696][ T5333] [ 147.439889][ T5333] ====================================================== [ 147.443084][ T5333] WARNING: possible circular locking dependency detected [ 147.446145][ T5333] syzkaller #0 Not tainted [ 147.448201][ T5333] ------------------------------------------------------ [ 147.450980][ T5333] syz.0.0/5333 is trying to acquire lock: [ 147.453274][ T5333] ffffffff8e860e08 (pcpu_alloc_mutex){+.+.}-{4:4}, at: pcpu_alloc_noprof+0x218/0x19c0 [ 147.457546][ T5333] [ 147.457546][ T5333] but task is already holding lock: [ 147.460699][ T5333] ffff88801f6d3990 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_throtl_init+0x279/0x410 [ 147.465176][ T5333] [ 147.465176][ T5333] which lock already depends on the new lock. [ 147.465176][ T5333] [ 147.469545][ T5333] [ 147.469545][ T5333] the existing dependency chain (in reverse order) is: [ 147.473314][ T5333] [ 147.473314][ T5333] -> #2 (&q->q_usage_counter(io)#17){++++}-{0:0}: [ 147.476993][ T5333] blk_alloc_queue+0x546/0x680 [ 147.479280][ T5333] __blk_mq_alloc_disk+0x197/0x390 [ 147.481666][ T5333] loop_add+0x482/0xb40 [ 147.483639][ T5333] loop_init+0xd9/0x170 [ 147.485675][ T5333] do_one_initcall+0x250/0x8d0 [ 147.487849][ T5333] do_initcall_level+0x104/0x190 [ 147.490201][ T5333] do_initcalls+0x59/0xa0 [ 147.491912][ T5333] kernel_init_freeable+0x2a6/0x3e0 [ 147.494167][ T5333] kernel_init+0x1d/0x1d0 [ 147.496218][ T5333] ret_from_fork+0x51e/0xb90 [ 147.498225][ T5333] ret_from_fork_asm+0x1a/0x30 [ 147.500264][ T5333] [ 147.500264][ T5333] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 147.503112][ T5333] fs_reclaim_acquire+0x71/0x100 [ 147.505250][ T5333] prepare_alloc_pages+0x152/0x650 [ 147.507706][ T5333] __alloc_frozen_pages_noprof+0x12f/0x380 [ 147.510295][ T5333] __alloc_pages_noprof+0xa/0x30 [ 147.512452][ T5333] pcpu_populate_chunk+0x182/0xb30 [ 147.514881][ T5333] pcpu_alloc_noprof+0xc6c/0x19c0 [ 147.517227][ T5333] iommu_dma_init_fq+0x279/0x610 [ 147.519618][ T5333] iommu_setup_dma_ops+0x6c3/0x1870 [ 147.522049][ T5333] bus_iommu_probe+0x296/0x470 [ 147.524443][ T5333] iommu_device_register+0x1af/0x210 [ 147.527043][ T5333] intel_iommu_init+0x6e3/0xa60 [ 147.529459][ T5333] pci_iommu_init+0x38/0x70 [ 147.531679][ T5333] do_one_initcall+0x250/0x8d0 [ 147.534141][ T5333] do_initcall_level+0x104/0x190 [ 147.536663][ T5333] do_initcalls+0x59/0xa0 [ 147.538833][ T5333] kernel_init_freeable+0x2a6/0x3e0 [ 147.541276][ T5333] kernel_init+0x1d/0x1d0 [ 147.543456][ T5333] ret_from_fork+0x51e/0xb90 [ 147.545753][ T5333] ret_from_fork_asm+0x1a/0x30 [ 147.548073][ T5333] [ 147.548073][ T5333] -> #0 (pcpu_alloc_mutex){+.+.}-{4:4}: [ 147.551234][ T5333] __lock_acquire+0x15a5/0x2cf0 [ 147.553627][ T5333] lock_acquire+0xf0/0x2e0 [ 147.555817][ T5333] __mutex_lock+0x19f/0x1300 [ 147.558084][ T5333] pcpu_alloc_noprof+0x218/0x19c0 [ 147.560495][ T5333] __percpu_counter_init_many+0x43/0x380 [ 147.563185][ T5333] blkg_rwstat_init+0x2c/0x170 [ 147.565519][ T5333] throtl_pd_alloc+0xb6/0x460 [ 147.567788][ T5333] blkcg_activate_policy+0x692/0xb40 [ 147.570235][ T5333] blk_throtl_init+0x2f6/0x410 [ 147.572537][ T5333] tg_set_conf+0x1d6/0x4c0 [ 147.574562][ T5333] cgroup_file_write+0x36f/0x790 [ 147.576911][ T5333] kernfs_fop_write_iter+0x3af/0x540 [ 147.579474][ T5333] vfs_write+0x61d/0xb90 [ 147.581569][ T5333] ksys_write+0x150/0x270 [ 147.583695][ T5333] do_syscall_64+0x14d/0xf80 [ 147.586196][ T5333] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 147.589070][ T5333] [ 147.589070][ T5333] other info that might help us debug this: [ 147.589070][ T5333] [ 147.593303][ T5333] Chain exists of: [ 147.593303][ T5333] pcpu_alloc_mutex --> fs_reclaim --> &q->q_usage_counter(io)#17 [ 147.593303][ T5333] [ 147.598913][ T5333] Possible unsafe locking scenario: [ 147.598913][ T5333] [ 147.602053][ T5333] CPU0 CPU1 [ 147.604299][ T5333] ---- ---- [ 147.606540][ T5333] lock(&q->q_usage_counter(io)#17); [ 147.608876][ T5333] lock(fs_reclaim); [ 147.611693][ T5333] lock(&q->q_usage_counter(io)#17); [ 147.615097][ T5333] lock(pcpu_alloc_mutex); [ 147.617097][ T5333] [ 147.617097][ T5333] *** DEADLOCK *** [ 147.617097][ T5333] [ 147.620459][ T5333] 7 locks held by syz.0.0/5333: [ 147.622540][ T5333] #0: ffff888043783b78 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 [ 147.626442][ T5333] #1: ffff888012216420 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 [ 147.630128][ T5333] #2: ffff888012ae5c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 [ 147.634406][ T5333] #3: ffff88801eff5c38 (kn->active#65){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 [ 147.638647][ T5333] #4: ffff88801f6d3b98 (&q->rq_qos_mutex){+.+.}-{4:4}, at: blkg_conf_open_bdev+0x2b0/0x3c0 [ 147.642916][ T5333] #5: ffff88801f6d3990 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_throtl_init+0x279/0x410 [ 147.647177][ T5333] #6: ffff88801f6d39c8 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: blk_throtl_init+0x279/0x410 [ 147.651526][ T5333] [ 147.651526][ T5333] stack backtrace: [ 147.654130][ T5333] CPU: 0 UID: 0 PID: 5333 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 147.654144][ T5333] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 147.654151][ T5333] Call Trace: [ 147.654158][ T5333] [ 147.654163][ T5333] dump_stack_lvl+0xe8/0x150 [ 147.654176][ T5333] print_circular_bug+0x2e1/0x300 [ 147.654190][ T5333] check_noncircular+0x12e/0x150 [ 147.654204][ T5333] __lock_acquire+0x15a5/0x2cf0 [ 147.654221][ T5333] lock_acquire+0xf0/0x2e0 [ 147.654232][ T5333] ? pcpu_alloc_noprof+0x218/0x19c0 [ 147.654248][ T5333] __mutex_lock+0x19f/0x1300 [ 147.654259][ T5333] ? pcpu_alloc_noprof+0x218/0x19c0 [ 147.654270][ T5333] ? kasan_save_track+0x4f/0x80 [ 147.654279][ T5333] ? kasan_save_track+0x3e/0x80 [ 147.654286][ T5333] ? __kasan_kmalloc+0x93/0xb0 [ 147.654294][ T5333] ? __kmalloc_cache_node_noprof+0x3ef/0x6b0 [ 147.654303][ T5333] ? blkcg_activate_policy+0x692/0xb40 [ 147.654309][ T5333] ? blk_throtl_init+0x2f6/0x410 [ 147.654316][ T5333] ? tg_set_conf+0x1d6/0x4c0 [ 147.654324][ T5333] ? pcpu_alloc_noprof+0x218/0x19c0 [ 147.654331][ T5333] ? kernfs_fop_write_iter+0x3af/0x540 [ 147.654352][ T5333] ? vfs_write+0x61d/0xb90 [ 147.654361][ T5333] ? ksys_write+0x150/0x270 [ 147.654368][ T5333] ? do_syscall_64+0x14d/0xf80 [ 147.654375][ T5333] ? __pfx___mutex_lock+0x10/0x10 [ 147.654383][ T5333] pcpu_alloc_noprof+0x218/0x19c0 [ 147.654393][ T5333] ? rcu_is_watching+0x15/0xb0 [ 147.654405][ T5333] __percpu_counter_init_many+0x43/0x380 [ 147.654417][ T5333] ? __kmalloc_cache_node_noprof+0x3ef/0x6b0 [ 147.654430][ T5333] blkg_rwstat_init+0x2c/0x170 [ 147.654440][ T5333] throtl_pd_alloc+0xb6/0x460 [ 147.654451][ T5333] ? __pfx_throtl_pd_alloc+0x10/0x10 [ 147.654461][ T5333] blkcg_activate_policy+0x692/0xb40 [ 147.654475][ T5333] blk_throtl_init+0x2f6/0x410 [ 147.654489][ T5333] tg_set_conf+0x1d6/0x4c0 [ 147.654498][ T5333] ? __pfx_tg_set_conf+0x10/0x10 [ 147.654506][ T5333] ? kernfs_root+0x1c/0x230 [ 147.654515][ T5333] ? kernfs_root+0x1c/0x230 [ 147.654523][ T5333] ? kernfs_root+0x1c/0x230 [ 147.654531][ T5333] ? kernfs_root+0x1ea/0x230 [ 147.654539][ T5333] ? __pfx_tg_set_conf_uint+0x10/0x10 [ 147.654547][ T5333] cgroup_file_write+0x36f/0x790 [ 147.654557][ T5333] ? __pfx_cgroup_file_write+0x10/0x10 [ 147.654566][ T5333] ? __pfx_cgroup_file_write+0x10/0x10 [ 147.654575][ T5333] kernfs_fop_write_iter+0x3af/0x540 [ 147.654586][ T5333] vfs_write+0x61d/0xb90 [ 147.654600][ T5333] ? __pfx_vfs_write+0x10/0x10 [ 147.654612][ T5333] ? __fget_files+0x2a/0x420 [ 147.654625][ T5333] ksys_write+0x150/0x270 [ 147.654638][ T5333] ? __pfx_ksys_write+0x10/0x10 [ 147.654652][ T5333] do_syscall_64+0x14d/0xf80 [ 147.654661][ T5333] ? trace_irq_disable+0x3b/0x150 [ 147.654672][ T5333] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 147.654678][ T5333] ? clear_bhb_loop+0x40/0x90 [ 147.654685][ T5333] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 147.654692][ T5333] RIP: 0033:0x7f0c71f9bf79 [ 147.654705][ T5333] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48 [ 147.654747][ T5333] RSP: 002b:00007f0c72f27028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 147.654807][ T5333] RAX: ffffffffffffffda RBX: 00007f0c72215fa0 RCX: 00007f0c71f9bf79 [ 147.654813][ T5333] RDX: 000000000000006a RSI: 00002000000000c0 RDI: 0000000000000005 [ 147.654819][ T5333] RBP: 00007f0c72f27090 R08: 0000000000000000 R09: 0000000000000000 [ 147.654825][ T5333] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 147.654831][ T5333] R13: 00007f0c72216038 R14: 00007f0c72215fa0 R15: 00007ffc77d65e28 [ 147.654842][ T5333]