INFO: task syz.1.3864:18374 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.1.3864 state:D stack:24832 pid:18374 tgid:18374 ppid:15794 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x121f/0x1c60 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_flush+0x673/0x8b0 fs/fuse/file.c:494 filp_flush+0xc0/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d7/0x900 fs/file.c:819 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae9d1cc819 RSP: 002b:00007ffd07bc7ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ffd07bc7bc0 RCX: 00007fae9d1cc819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00000000001120d4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2d320000 R11: 0000000000000246 R12: 00007ffd07bc7c00 R13: 00007fae9d44609c R14: 000000000011215d R15: 00007fae9d446090 Showing all locks held in the system: 1 lock held by rcu_preempt/18: #0: ffff8880b883b7e0 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 4 locks held by rcuc/0/20: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5558: #0: ffff8880370300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:3/5869: 5 locks held by kworker/u8:14/6288: 2 locks held by syz-executor/18557: 2 locks held by syz.6.4387/20088: #0: ffff8880345d0f78 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff8880345d0f78 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff8880345d0f78 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffff88803ffcf358 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline] #1: ffff88803ffcf358 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1cd/0x960 net/can/bcm.c:1612 5 locks held by syz.7.4392/20105: #0: ffff88802c132ab0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88802c132ab0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x194/0xa10 mm/mmap.c:1286 #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #1: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:288 #2: ffff888032bb8598 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff888032bb8598 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402 #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffff88813fffc5d8 (&zone->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #4: ffff88813fffc5d8 (&zone->lock){+.+.}-{3:3}, at: rmqueue_buddy mm/page_alloc.c:3252 [inline] #4: ffff88813fffc5d8 (&zone->lock){+.+.}-{3:3}, at: rmqueue mm/page_alloc.c:3424 [inline] #4: ffff88813fffc5d8 (&zone->lock){+.+.}-{3:3}, at: get_page_from_freelist+0xd9f/0x2950 mm/page_alloc.c:3959 6 locks held by syz.0.4393/20107: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 6288 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:check_preemption_disabled+0x29/0xe0 lib/smp_processor_id.c:19 Code: 90 55 41 57 41 56 53 65 8b 05 47 93 2a 07 65 8b 0d 3c 93 2a 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9 99 a5 03 00 cc 9c <59> f7 c1 00 02 00 00 74 ea 65 4c 8b 3d ee 92 2a 07 41 f6 47 2f 04 RSP: 0018:ffffc90005bef410 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000246 RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8d57e35c RDI: ffffffff8ba67a80 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90005bef5d8 R11: ffffffff81af8df0 R12: 0000000000000002 R13: ffffffff8ddcb980 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2b023c CR3: 00000000604be000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_acquire+0xb9/0x2e0 kernel/locking/lockdep.c:5867 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 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 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_node_track_caller_noprof+0x372/0x7e0 mm/slub.c:5368 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245