INFO: task syz.0.17:5946 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25544 pid:5946 ppid:5899 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x9b/0x280 kernel/time/timer.c:2143 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3cb/0x6d0 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:443 [inline] do_coredump+0x85c/0x2480 fs/coredump.c:640 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f8711a4f927 RSP: 002b:00007fff322b40e0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000019640 RDX: 00007fff322b4100 RSI: 00007fff322b4230 RDI: 000000000000000b RBP: 00007f8711dd7da0 R08: 0000000000000068 R09: 0000000000745d1e R10: 000000379366409e R11: 0000000000004b96 R12: 00000000000199f6 R13: 00007f8711dd6090 R14: ffffffffffffffff R15: 00007fff323b2ee0 INFO: task syz.0.17:5948 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:26856 pid:5948 ppid:5899 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 coredump_task_exit kernel/exit.c:436 [inline] do_exit+0x4a0/0x23c0 kernel/exit.c:825 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8711b8eba9 RSP: 002b:00007f87129450e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f8711dd6098 RCX: 00007f8711b8eba9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8711dd6098 RBP: 00007f8711dd6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8711dd6128 R14: 00007fff323b2b80 R15: 00007fff323b2c68 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:7/1326: 1 lock held by klogd/5147: #0: ffff8880b8f3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 2 locks held by getty/5549: #0: ffff888030daa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 ============================================= 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 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 48 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline] RIP: 0010:unwind_next_frame+0x220/0x2970 arch/x86/kernel/unwind_orc.c:494 Code: 00 00 49 29 df 49 c1 ef 08 8b 05 d3 9b 42 0b 48 89 44 24 28 8d 68 ff 89 ef 44 89 fe e8 e9 ec 4a 00 44 39 fd 0f 86 4f 1d 00 00 <44> 89 f8 4c 8d 2c 85 0c f1 71 8f 4c 89 e8 48 c1 e8 03 48 bb 00 00 RSP: 0018:ffffc90000b8f558 EFLAGS: 00000216 RAX: ffffffff813aa4d7 RBX: ffffffff81000000 RCX: 0000000000000000 RDX: ffff88801a2fbc00 RSI: 00000000000057c6 RDI: 000000000009a000 RBP: 000000000009a000 R08: ffffc90000b8f6f0 R09: 0000000000000006 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90000b8f628 R13: dffffc0000000000 R14: ffffc90000b8f65d R15: 00000000000057c6 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e0b4410168 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3540 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640 alloc_skb include/linux/skbuff.h:1284 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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