INFO: task syz-executor:5843 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21672 pid:5843 tgid:5843 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 __folio_lock mm/filemap.c:1675 [inline] folio_lock include/linux/pagemap.h:1133 [inline] __filemap_get_folio+0x167/0xa40 mm/filemap.c:1929 truncate_inode_pages_range+0x3cf/0xb90 mm/truncate.c:388 evict+0x517/0x9c0 fs/inode.c:812 dispose_list fs/inode.c:852 [inline] evict_inodes+0x64c/0x6d0 fs/inode.c:906 generic_shutdown_super+0x9a/0x2c0 fs/super.c:628 kill_block_super+0x44/0x90 fs/super.c:1766 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff58fba01f7 RSP: 002b:00007ffd89002c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff58fc21d7d RCX: 00007ff58fba01f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd89002d30 RBP: 00007ffd89002d30 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd89003dc0 R13: 00007ff58fc21d7d R14: 000000000008d318 R15: 00007ffd89003e00 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/748: 2 locks held by udevd/5207: 2 locks held by getty/5599: #0: ffff88823bf8e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5843: #0: ffff88801a3f20d0 (&type->s_umount_key#125){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88801a3f20d0 (&type->s_umount_key#125){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88801a3f20d0 (&type->s_umount_key#125){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 9 locks held by syz-executor/12327: 3 locks held by syz.3.2964/14173: 2 locks held by syz.5.2963/14182: 2 locks held by syz.1.2969/14186: 5 locks held by syz.7.2968/14188: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 3542 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rt_spin_unlock+0x7a/0x80 kernel/locking/spinlock_rt.c:85 Code: 00 00 48 c7 c2 20 0f 0b 8b e8 42 a7 a2 f6 48 8d 35 00 00 00 00 48 c7 c7 80 8d 9a 8d e8 1f 8d a2 f6 e8 ca 4b ac f6 48 89 df 5b 14 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000dc67808 EFLAGS: 00000283 RAX: 0000000000000001 RBX: ffff8880b883f8d0 RCX: 8ccdf0af79d5c500 RDX: 0000000000000005 RSI: ffffffff8d21b188 RDI: ffff8880b883f8d0 RBP: ffffea0001e37400 R08: 0000000000000000 R09: ffffffff8af97c4b R10: 0000000000000000 R11: fffffbfff1e3ac47 R12: 0000000000000000 R13: ffffffff91f838d0 R14: 0000000000000000 R15: ffff888078dd4000 FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d272456c0 CR3: 0000000038da6000 CR4: 00000000003526f0 Call Trace: spin_unlock include/linux/spinlock_rt.h:105 [inline] ___slab_alloc+0x4d2/0xdc0 mm/slub.c:3806 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_node_track_caller_noprof+0x14c/0x450 mm/slub.c:4395 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:600 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:669 alloc_skb include/linux/skbuff.h:1336 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:866 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245