INFO: task syz.1.822:10912 blocked for more than 143 seconds. Not tainted 6.11.0-next-20240927-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.822 state:D stack:23808 pid:10912 tgid:10912 ppid:9505 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __vhost_worker_flush+0x1e6/0x280 drivers/vhost/vhost.c:288 vhost_worker_flush drivers/vhost/vhost.c:295 [inline] vhost_dev_flush+0xc9/0x150 drivers/vhost/vhost.c:305 vhost_net_flush+0x24/0x160 drivers/vhost/net.c:1359 vhost_net_release+0x109/0x470 drivers/vhost/net.c:1380 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f3337df39 RSP: 002b:00007ffd45401f98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f5f33537a80 RCX: 00007f5f3337df39 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5f33537a80 R08: 0000000000000006 R09: 00007ffd4540228f R10: 00000000003ffbcc R11: 0000000000000246 R12: 00000000000b8142 R13: 00007ffd454020a0 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:12/3076: 1 lock held by udevd/4690: 2 locks held by getty/4991: #0: ffff88814bd710a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz.0.868/11927: #0: ffffffff8e93d240 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4561 1 lock held by syz.0.868/11930: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-next-20240927-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11930 Comm: syz.0.868 Not tainted 6.11.0-next-20240927-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x70 kernel/kcov.c:213 Code: 00 00 00 48 8b 3d c4 1c 9d 0c 48 89 de 5b e9 03 d9 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 04 24 65 48 8b 0c 25 c0 d7 03 00 65 8b 15 20 02 6f 7e 81 e2 RSP: 0018:ffffc90003a178f8 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff92000742fa7 RDX: ffff888027ae8000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003a17a70 R08: ffffffff8989703b R09: 1ffff92000742ed0 R10: dffffc0000000000 R11: fffff52000742ed1 R12: 000000002024f7c0 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fa0123cb6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005576e2575950 CR3: 000000006a940000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ____sys_recvmsg+0x30b/0x480 ___sys_recvmsg net/socket.c:2864 [inline] do_recvmmsg+0x45e/0xad0 net/socket.c:2958 __sys_recvmmsg net/socket.c:3037 [inline] __do_sys_recvmmsg net/socket.c:3060 [inline] __se_sys_recvmmsg net/socket.c:3053 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3053 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa01157df39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa0123cb038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fa011736058 RCX: 00007fa01157df39 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fa0115f0216 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa011736058 R15: 00007ffcdcf2a158