INFO: task syz-executor.2:3896 blocked for more than 143 seconds. Not tainted 5.16.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28080 pid: 3896 ppid: 3647 flags:0x20000004 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4f00 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6428 __mutex_lock_common kernel/locking/mutex.c:673 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:733 vhost_net_stop_vq drivers/vhost/net.c:1359 [inline] vhost_net_stop+0x142/0x270 drivers/vhost/net.c:1373 vhost_net_release+0x9c/0x2d0 drivers/vhost/net.c:1405 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6eb8549 RSP: 002b:00000000f7549b20 EFLAGS: 00000286 ORIG_RAX: 0000000000000006 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 00000000f6ff0000 RDI: 0000000000000000 RBP: 00000000f701a6c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb852e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460 2 locks held by getty/3282: #0: ffff88807ee09098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002b632e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077 1 lock held by syz-executor.2/3896: #0: ffff888042920218 (&vq->mutex){+.+.}-{3:3}, at: vhost_net_stop_vq drivers/vhost/net.c:1359 [inline] #0: ffff888042920218 (&vq->mutex){+.+.}-{3:3}, at: vhost_net_stop+0x142/0x270 drivers/vhost/net.c:1373 1 lock held by vhost-3897/3898: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200 Code: 46 00 5d be 03 00 00 00 e9 76 f0 64 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 c9 23 8a 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 RSP: 0018:ffffc90000da7b48 EFLAGS: 00000283 RAX: 0000000080000001 RBX: ffff88823bc8b000 RCX: ffff88823bc8b000 RDX: 0000000000000000 RSI: ffff888011a18000 RDI: 0000000000000003 RBP: ffff88823bc8a416 R08: ffff88823bc8a416 R09: 00000000ffffffaf R10: ffffffff81bfab5a R11: 00000000000000af R12: ffffffff90541c40 R13: ffff88823bc8a000 R14: 00000000ffffffaf R15: 00000000000000af FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000b55038 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: for_each_canary mm/kfence/core.c:352 [inline] kfence_guarded_free+0x368/0x930 mm/kfence/core.c:498 __kfence_free+0x70/0x150 mm/kfence/core.c:949 do_slab_free mm/slub.c:3497 [inline] slab_free mm/slub.c:3510 [inline] kmem_cache_free+0x323/0x340 mm/slub.c:3526 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:700 __kfree_skb net/core/skbuff.c:757 [inline] consume_skb net/core/skbuff.c:914 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:908 nsim_dev_trap_report drivers/net/netdevsim/dev.c:818 [inline] nsim_dev_trap_report_work+0x85d/0xbc0 drivers/net/netdevsim/dev.c:843 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 46 00 5d be rex.RX add %r11b,-0x42(%rbp) 4: 03 00 add (%rax),%eax 6: 00 00 add %al,(%rax) 8: e9 76 f0 64 02 jmpq 0x264f083 d: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 13: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi 1a: e8 b4 ff ff ff callq 0xffffffd3 1f: 31 c0 xor %eax,%eax 21: c3 retq 22: 90 nop 23: 65 8b 05 c9 23 8a 7e mov %gs:0x7e8a23c9(%rip),%eax # 0x7e8a23f3 * 2a: 89 c1 mov %eax,%ecx <-- trapping instruction 2c: 48 8b 34 24 mov (%rsp),%rsi 30: 81 e1 00 01 00 00 and $0x100,%ecx 36: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx 3d: 02 00 3f: a9 .byte 0xa9