INFO: task syz.2.328:7248 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.328 state:D stack:28824 pid:7248 tgid:7246 ppid:5825 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747 bdev_release+0x15a/0x6d0 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:684 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 get_signal+0x1d1/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d71b8e9a9 RSP: 002b:00007f0d729c3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f0d71db5fa0 RCX: 00007f0d71b8e9a9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f0d71c10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0d71db5fa0 R15: 00007fff17189288 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:7/1105: #0: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #0: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 #1: ffff8880b8524088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 2 locks held by getty/5598: #0: ffff8880329040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by kworker/u8:10/6379: #0: ffff888144aaa148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90010437d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 1 lock held by udevd/6429: #0: ffff888026a46358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.2.328/7248: #0: ffff888026a46358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1128 1 lock held by syz.6.782/9020: #0: ffff888026a46358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1105 Comm: kworker/u8:7 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: iou_exit io_ring_exit_work RIP: 0010:kasan_check_byte include/linux/kasan.h:399 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5845 [inline] RIP: 0010:lock_acquire+0xf4/0x350 kernel/locking/lockdep.c:5828 Code: 44 89 f2 48 89 de e8 6b d5 fe ff 5f 41 58 65 ff 0d 81 75 37 12 0f 85 4f ff ff ff e8 a6 da 93 ff e9 45 ff ff ff 48 8b 74 24 68 <48> 89 df e8 44 87 88 00 8b 0d 72 e7 10 0f 85 c9 0f 84 b1 00 00 00 RSP: 0018:ffffc90003cff580 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff8e5c4e00 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff816ad7a1 RDI: ffffffff8df3dda8 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000001213a R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124820000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9063782ab8 CR3: 000000007fd92000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x15a/0x4d0 mm/slub.c:4745 __io_req_caches_free+0x90/0x3d0 io_uring/io_uring.c:2709 io_req_caches_free io_uring/io_uring.c:2721 [inline] io_ring_exit_work+0x3b9/0x1120 io_uring/io_uring.c:2919 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245