INFO: task kworker/u4:2:154 blocked for more than 143 seconds. Not tainted 5.15.162-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:19744 pid: 154 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102 jfs_write_inode+0x13f/0x210 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_background_flush fs/fs-writeback.c:2172 [inline] wb_do_writeback fs/fs-writeback.c:2260 [inline] wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/154: #0: ffff8881447b4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900010cfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff8880737740e0 (&type->s_umount_key#70){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88806313b008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x242/0x580 fs/jfs/inode.c:102 2 locks held by udevd/2962: #0: ffff88801b70c118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817 #1: ffff8881471e1468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x68/0x100 drivers/block/loop.c:2055 2 locks held by getty/3261: #0: ffff888023fa3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc9000229b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 2 locks held by udevd/3500: #0: ffff8881471d8118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912 #1: ffff88801b6ee468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365 1 lock held by syz-executor/3516: #0: ffff8881471d8118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817 2 locks held by kworker/1:5/3553: #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90003067d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 6 locks held by kworker/0:6/3555: #0: ffff8881419b1538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90003097d20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88801e01d220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #2: ffff88801e01d220 (&dev->mutex){....}-{3:3}, at: hub_event+0x208/0x54c0 drivers/usb/core/hub.c:5769 #3: ffff8880193cc220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #3: ffff8880193cc220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:954 #4: ffff8880657701a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #4: ffff8880657701a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:954 #5: ffff888147d40768 (hcd->bandwidth_mutex){+.+.}-{3:3}, at: usb_set_interface+0x35a/0x1390 drivers/usb/core/message.c:1559 1 lock held by syz-executor/3654: #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 4 locks held by syz.0.151/4616: 1 lock held by syz.3.646/6937: #0: ffff8881471e1468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.162-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4616 Comm: syz.0.151 Not tainted 5.15.162-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:197 Code: 54 14 82 7e 65 8b 15 55 14 82 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 RSP: 0018:ffffc90003187018 EFLAGS: 00000246 RAX: ffffffff82e3a0ca RBX: ffff88807e8a2000 RCX: ffff88801ddb1dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000ff RBP: ffffc90003187210 R08: ffffffff82e3a09c R09: ffffed100fd14424 R10: 0000000000000004 R11: dffffc0000000001 R12: 1ffff1100fd14400 R13: dffffc0000000000 R14: ffff88806313b270 R15: 0000000000000000 FS: 00007f91aab606c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f30bff8 CR3: 000000007e744000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dtSplitRoot+0x8da/0x1920 fs/jfs/jfs_dtree.c:1978 dtSplitUp fs/jfs/jfs_dtree.c:990 [inline] dtInsert+0x12f6/0x6b00 fs/jfs/jfs_dtree.c:868 jfs_create+0x7b2/0xbb0 fs/jfs/namei.c:137 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x130a/0x2f20 fs/namei.c:3739 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f91ac100bd9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f91aab60048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f91ac28f038 RCX: 00007f91ac100bd9 RDX: 000000000000275a RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 00007f91ac16fe60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f91ac28f038 R15: 00007ffd1afcf488