INFO: task syz.5.5077:23151 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.5077 state:D stack:27752 pid:23151 ppid:21975 flags:0x00004004 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x27f1/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc5c7f5b58e RSP: 002b:00007fc5c8e17b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc5c8e186c0 RCX: 00007fc5c7f5b58e RDX: 0000000000080000 RSI: 00007fc5c8e17c00 RDI: ffffffffffffff9c RBP: 00007fc5c8e17c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fc5c8216038 R14: 00007fc5c8215fa0 R15: 00007ffcc9a90428 INFO: task syz.5.5077:23153 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.5077 state:D stack:28936 pid:23153 ppid:21975 flags:0x00004004 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747 blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 bdev_open_by_dev+0x77/0x100 block/bdev.c:859 setup_bdev_super+0x59/0x660 fs/super.c:1496 mount_bdev+0x1d3/0x2d0 fs/super.c:1640 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc5c7f9acb9 RSP: 002b:00007fc5c8df7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc5c8216090 RCX: 00007fc5c7f9acb9 RDX: 0000200000000080 RSI: 0000200000004a00 RDI: 0000200000000000 RBP: 00007fc5c8008bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000002008087 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc5c8216128 R14: 00007fc5c8216090 R15: 00007ffcc9a90428 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8d1379b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8d1379b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by khungtaskd/29: #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:3/49: #0: ffff88801f289538 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801f289538 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc90000ba7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000ba7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 2 locks held by kworker/u4:7/2908: #0: ffff88801f289538 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801f289538 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000c717d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000c717d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 4 locks held by kworker/u4:8/2963: 2 locks held by getty/5531: #0: ffff88802db5e0a0 (&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 1 lock held by udevd/6897: #0: ffff8881413c04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz-executor/20575: 1 lock held by syz.5.5077/23151: #0: ffff8881413c04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz.5.5077/23153: #0: ffff8881413c04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 1 lock held by syz.7.5719/25941: 3 locks held by kworker/u4:5/26009: 2 locks held by sed/26122: ============================================= 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 10/25/2025 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: 20575 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:unwind_next_frame+0x1cfd/0x2970 arch/x86/kernel/unwind_orc.c:672 Code: c3 08 d3 4c 89 f7 48 89 ee e8 2f c2 4b 00 80 fb 01 0f 85 81 01 00 00 e8 11 c0 4b 00 eb 0c e8 0a c0 4b 00 eb 05 e8 03 c0 4b 00 01 00 00 00 e8 a9 2c 21 00 65 8b 1d 9a 62 c8 7e 31 ff 89 de e8 RSP: 0018:ffffc900033d7398 EFLAGS: 00000293 RAX: ffffffff813b530f RBX: ffffc900033d0001 RCX: ffff888061439e00 RDX: 0000000000000000 RSI: ffffc900033d7da0 RDI: ffffc900033d7e00 RBP: ffffc900033d7da0 R08: ffff888061439e00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900033d7468 R13: dffffc0000000000 R14: ffffc900033d7e00 R15: ffffc900033d7478 FS: 000055557f07e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000cf1000 CR3: 0000000060751000 CR4: 00000000003506e0 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 f2fs_destroy_node_manager+0x36c/0xd40 fs/f2fs/node.c:3338 f2fs_put_super+0xb6b/0x1430 fs/f2fs/super.c:1669 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1660 kill_f2fs_super+0x326/0x3d0 fs/f2fs/super.c:4856 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 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+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd99a99bf17 Code: a2 c7 05 7c 96 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffe9acd50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fd99aa0471f RCX: 00007fd99a99bf17 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe9acd51a0 RBP: 00007ffe9acd51a0 R08: 00007ffe9acd61a0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe9acd6230 R13: 00007fd99aa0471f R14: 000000000011875d R15: 00007ffe9acd6270