INFO: task syz.0.1612:11979 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1612 state:D stack:25448 pid:11979 ppid:5783 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1267 [inline] io_wq_put_and_exit+0x474/0x810 io_uring/io-wq.c:1295 io_uring_clean_tctx+0x130/0x1b0 io_uring/tctx.c:204 io_uring_cancel_generic+0x610/0x6c0 io_uring/io_uring.c:3507 io_uring_files_cancel include/linux/io_uring.h:69 [inline] do_exit+0x5f1/0x2460 kernel/exit.c:830 do_group_exit+0x21b/0x2d0 kernel/exit.c:1026 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f571d99ce59 RSP: 002b:00007f571e7a7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000db RAX: fffffffffffffdfc RBX: 00007f571dc15fa0 RCX: 00007f571d99ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000001a80 RBP: 00007f571da32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f571dc16038 R14: 00007f571dc15fa0 R15: 00007fff19ec1778 INFO: task iou-wrk-11979:11980 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:iou-wrk-11979 state:D stack:25032 pid:11980 ppid:5783 flags:0x00024006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7d0 mm/filemap.c:3791 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x340 block/partitions/core.c:718 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x740/0x1420 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:672 blkdev_get_by_dev+0x279/0x600 block/bdev.c:814 disk_scan_partitions+0x1bc/0x2c0 block/genhd.c:367 device_add_disk+0xc1a/0xf50 block/genhd.c:509 add_disk include/linux/blkdev.h:748 [inline] ublk_ctrl_start_dev+0xadb/0xfd0 drivers/block/ublk_drv.c:2282 ublk_ctrl_uring_cmd+0x3b4/0x5e0 drivers/block/ublk_drv.c:2938 io_uring_cmd+0x149/0x410 io_uring/uring_cmd.c:139 io_issue_sqe+0x2c5/0xc90 io_uring/io_uring.c:1869 io_wq_submit_work+0x418/0x9c0 io_uring/io_uring.c:1956 io_worker_handle_work+0x847/0x11b0 io_uring/io-wq.c:602 io_wq_worker+0x4a0/0xf10 io_uring/io-wq.c:656 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d132120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by udevd/5145: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695 2 locks held by getty/5541: #0: ffff88814ca730a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by iou-wrk-11979/11980: #0: ffff88802e85e6c0 (&ub->mutex){+.+.}-{3:3}, at: ublk_ctrl_start_dev+0xf8/0xfd0 drivers/block/ublk_drv.c:2246 #1: ffff8880607af4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz.2.1618/12002: #0: ffff88801cfd6418 (sb_writers#3){.+.+}-{0:0}, at: do_sendfile+0x5cf/0xef0 fs/read_write.c:1253 3 locks held by kworker/1:3/12350: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90005387d00 (binder_deferred_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90005387d00 (binder_deferred_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8d137af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #2: ffffffff8d137af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__lock_acquire+0xde6/0x7d40 kernel/locking/lockdep.c:5110 Code: df 48 0f a3 1d fb 81 b4 0f 0f 83 c5 50 00 00 49 8d 9d d0 0a 00 00 48 89 d8 48 c1 e8 03 48 89 84 24 b8 00 00 00 42 80 3c 00 00 <74> 12 48 89 df e8 10 28 77 00 49 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc900001f0a80 EFLAGS: 00000046 RAX: 1ffff110036cd8da RBX: ffff88801b66c6d0 RCX: ffffffff816842f3 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911cc508 RBP: ffffc900001f0cc8 R08: dffffc0000000000 R09: 1ffffffff22398a1 R10: dffffc0000000000 R11: fffffbfff22398a2 R12: ffff88801b66c6c4 R13: ffff88801b66bc00 R14: ffff88801b66c708 R15: ffff88801b66c728 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000002c000 CR3: 000000005e2a2000 CR4: 00000000003506e0 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access+0xd1/0x1d0 include/linux/seqlock.h:102 ktime_get+0x35/0x280 kernel/time/timekeeping.c:846 tick_nohz_start_idle+0xf7/0x200 kernel/time/tick-sched.c:686 tick_irq_exit kernel/softirq.c:646 [inline] __irq_exit_rcu+0x115/0x190 kernel/softirq.c:663 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: b8 1f 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 43 24 40 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2 RAX: 1635d6af80c56c00 RBX: ffffffff8162afbd RCX: 1635d6af80c56c00 RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9a20 RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65 R10: dffffc0000000000 R11: ffffed10171e6d66 R12: 1ffff92000030fc8 R13: dffffc0000000000 R14: 1ffff110036cd780 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:178 [inline] do_idle+0x33d/0x590 kernel/sched/idle.c:302 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401 start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323 secondary_startup_64_no_verify+0x179/0x17b