INFO: task syz-executor.0:5395 blocked for more than 143 seconds. Not tainted 6.6.0-rc1-syzkaller-00191-gd8d7cd656361 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:24808 pid:5395 ppid:5374 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1873/0x48f0 kernel/sched/core.c:6695 schedule+0xc3/0x180 kernel/sched/core.c:6771 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2143 do_wait_for_common+0x449/0x5f0 kernel/sched/completion.c:95 __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x4a/0x60 kernel/sched/completion.c:148 __flush_workqueue+0x743/0x1620 kernel/workqueue.c:3195 nbd_start_device_ioctl drivers/block/nbd.c:1426 [inline] __nbd_ioctl drivers/block/nbd.c:1486 [inline] nbd_ioctl+0xb11/0xe60 drivers/block/nbd.c:1526 blkdev_ioctl+0x5cf/0x730 block/ioctl.c:630 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x456e69 RSP: 002b:00007f2737c320d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000055bf80 RCX: 0000000000456e69 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00000000004b0cab R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004b02b7 R13: 000000000000000b R14: 000000000055bf80 R15: 00007fff1814e928 Showing all locks held in the system: 2 locks held by kworker/u4:1/12: 1 lock held by khungtaskd/29: #0: ffffffff8d32c460 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u5:0/50: #0: ffff88801c7d8d38 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x651/0x1130 #1: ffffc90000bafd20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x68e/0x1130 kernel/workqueue.c:2605 2 locks held by getty/4781: #0: ffff88814a9ce0a0 (&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+0x6b1/0x1dc0 drivers/tty/n_tty.c:2206 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc1-syzkaller-00191-gd8d7cd656361 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 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+0xdf5/0xe40 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4462 Comm: syslogd Not tainted 6.6.0-rc1-syzkaller-00191-gd8d7cd656361 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 RIP: 0010:in_gate_area_no_mm+0x0/0x50 arch/x86/entry/vsyscall/vsyscall_64.c:344 Code: 0b 4c 89 ff 4c 89 f6 e8 3e 20 8d 00 45 31 e4 4d 39 f7 41 0f 97 c4 44 89 e0 5b 41 5c 41 5e 41 5f c3 66 0f 1f 84 00 00 00 00 00 <66> 0f 1f 00 55 53 48 89 fb e8 02 1e 8d 00 8b 2d 5c 2a cb 0b bf 02 RSP: 0018:ffffc900030af420 EFLAGS: 00000207 RAX: ffffffff81000000 RBX: 00007f35323ccb6a RCX: ffff88807e0a1dc0 RDX: ffff88807e0a1dc0 RSI: 0000000000000001 RDI: 00007f35323ccb6a RBP: 0000000000000001 R08: ffffffff813d8df7 R09: ffffffff813da8d0 R10: 0000000000000003 R11: ffff88807e0a1dc0 R12: ffff88807e0a1dc0 R13: ffffffff817b6a20 R14: dffffc0000000000 R15: 1ffff92000615e99 FS: 00007f3532278380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561928868680 CR3: 000000002986a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: is_kernel_text include/linux/kallsyms.h:31 [inline] core_kernel_text kernel/extable.c:68 [inline] kernel_text_address+0x30/0xe0 kernel/extable.c:99 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11f/0x1a0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x117/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0x25f/0x3b0 mm/slub.c:3822 skb_kfree_head net/core/skbuff.c:945 [inline] skb_free_head net/core/skbuff.c:957 [inline] skb_release_data+0x660/0x850 net/core/skbuff.c:987 skb_release_all net/core/skbuff.c:1053 [inline] __kfree_skb net/core/skbuff.c:1067 [inline] consume_skb+0xb3/0x150 net/core/skbuff.c:1283 __unix_dgram_recvmsg+0xcb7/0x1260 net/unix/af_unix.c:2442 sock_recvmsg_nosec net/socket.c:1027 [inline] sock_recvmsg net/socket.c:1049 [inline] sock_read_iter+0x3ab/0x500 net/socket.c:1119 call_read_iter include/linux/fs.h:1979 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x795/0xb00 fs/read_write.c:470 ksys_read+0x1a0/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f35323ccb6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007fff181769a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f35323ccb6a RDX: 00000000000000ff RSI: 000055d6a1b16950 RDI: 0000000000000000 RBP: 000055d6a1b16910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f353256b3a3 R11: 0000000000000246 R12: 000055d6a1b1699e R13: 000055d6a1b16950 R14: 0000000000000000 R15: 00007f35325a9a80