INFO: task syz.8.839:9654 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.839 state:D stack:25864 pid:9654 tgid:9653 ppid:7373 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 sync_bdevs+0x276/0x470 block/bdev.c:1297 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f99e299de99 RSP: 002b:00007f99e3937028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f99e2c25fa0 RCX: 00007f99e299de99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f99e2c25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f99e2c26038 R14: 00007f99e2c25fa0 R15: 00007fff41421938 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by khungtaskd/31: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5374: #0: ffff8880357120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 1 lock held by udevd/5742: #0: ffff88802615a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948 1 lock held by syz-executor/6608: #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.8.839/9654: #0: ffff88802615a350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1297 1 lock held by syz.2.1281/11463: #0: ffff88802615a350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x276/0x470 block/bdev.c:1297 2 locks held by syz.5.1283/11520: 4 locks held by syz.6.1305/11556: #0: ffff8880560360d8 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: alloc_super fs/super.c:345 [inline] #0: ffff8880560360d8 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: sget_fc+0x938/0x1900 fs/super.c:766 #1: ffff8880b863b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 #2: ffffffff8e814988 (mount_lock.seqcount){+.+.}-{0:0}, at: mount_subtree+0x195/0x3a0 fs/namespace.c:4351 #3: ffff88805429b148 (&new_ns->poll){..-.}-{3:3}, at: __wake_up_common_lock+0x30/0x1f0 kernel/sched/wait.c:124 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6608 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:unwind_next_frame+0x57/0x2550 arch/x86/kernel/unwind_orc.c:486 Code: 24 20 42 80 3c 20 00 74 05 e8 a5 11 bd 00 49 8b 5e 48 49 8d 7e 38 48 89 fd 48 c1 ed 03 42 80 7c 25 00 00 74 05 e8 89 11 bd 00 <4d> 8b 6e 38 4d 89 f7 49 c1 ef 03 43 0f b6 04 27 84 c0 0f 85 bd 1b RSP: 0018:ffffc9000db5f000 EFLAGS: 00000246 RAX: 1ffff92001b6be1e RBX: ffffffff82348c80 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff82348c80 RDI: ffffc9000db5f0e0 RBP: 1ffff92001b6be1c R08: ffffc9000db5f170 R09: 0000000000000001 R10: dffffc0000000000 R11: ffffffff81b1fa10 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffc9000db5f0a8 R15: ffffc9000db5f0a8 FS: 00005555732e6500(0000) GS:ffff888124f50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557b9994e8 CR3: 0000000021302000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6504 free_buffer_head+0x55/0x220 fs/buffer.c:2978 try_to_free_buffers+0x25d/0x300 fs/buffer.c:2919 block_invalidate_folio+0x5fd/0x740 fs/buffer.c:1652 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0xcb/0x190 mm/truncate.c:160 truncate_inode_pages_range+0x2c1/0xd80 mm/truncate.c:404 evict_linked_inode fs/gfs2/super.c:1420 [inline] gfs2_evict_inode+0x931/0x1400 fs/gfs2/super.c:1482 evict+0x624/0xb50 fs/inode.c:825 gfs2_put_super+0x7c6/0x870 fs/gfs2/super.c:634 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1665 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f330259f0d7 Code: a2 c7 05 1c 26 25 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:00007ffd0a939218 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f330263330a RCX: 00007f330259f0d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd0a9392d0 RBP: 00007ffd0a9392d0 R08: 00007ffd0a93a2d0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd0a93a360 R13: 00007f330263330a R14: 0000000000086c9d R15: 00007ffd0a93a3a0