syzbot

INFO: task syz-executor814:5054 blocked for more than 143 seconds.
      Not tainted 6.8.0-rc1-syzkaller-00311-g3a5879d495b2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor814 state:D stack:27648 pid:5054  tgid:5054  ppid:5053   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0xf12/0x5c00 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0xe9/0x270 kernel/sched/core.c:6817
 schedule_timeout+0x257/0x290 kernel/time/timer.c:2159
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3e0/0x5f0 kernel/sched/completion.c:116
 __flush_workqueue+0x3e0/0x1340 kernel/workqueue.c:3198
 nbd_start_device_ioctl drivers/block/nbd.c:1443 [inline]
 __nbd_ioctl drivers/block/nbd.c:1504 [inline]
 nbd_ioctl+0x308/0xd60 drivers/block/nbd.c:1544
 blkdev_ioctl+0x2f3/0x760 block/ioctl.c:634
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f9e6bf21879
RSP: 002b:00007fffbf638dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9e6bf21879
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f9e6bf945f0 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000001
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d1a9120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8d1a9120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8d1a9120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614
2 locks held by kworker/u4:12/2912:
2 locks held by kworker/u5:1/4446:
 #0: ffff88801e6d4538 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2608
 #1: ffffc9000d6d7d80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2609
2 locks held by getty/4805:
 #0: ffff888029a370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc1-syzkaller-00311-g3a5879d495b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x299/0x300 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+0xf87/0x1210 kernel/hung_task.c:379
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4492 Comm: klogd Not tainted 6.8.0-rc1-syzkaller-00311-g3a5879d495b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x310/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 76 c4 4c 00 8b 54 24 34 48 8d 14 52 48 8d 94 12 4c 93 bf 8f 48 81 fa ac 1e 76 90 0f 87 e8 09 00 00 e8 54 c4 4c 00 8b 54 24 34 <4c> 89 e1 4c 89 ee 8b 44 24 28 4a 8d 3c b5 0c e1 45 8f 29 c2 e8 c7
RSP: 0018:ffffc90003447458 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffc900034474d8 RCX: ffffffff813a4741
RDX: 0000000000176cb7 RSI: ffffffff813a481c RDI: ffffffff9093e00c
RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000077057
R10: 000000000009c000 R11: 0000000000000200 R12: ffffffff887057e4
R13: ffffffff904c1f90 R14: 0000000000176cb6 R15: ffffc9000344750d
FS:  00007f37378a6380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564465ab3680 CR3: 000000002b915000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:372 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:389
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:3981 [inline]
 __kmalloc_node_track_caller+0x219/0x460 mm/slub.c:4001
 kmalloc_reserve+0xef/0x260 net/core/skbuff.c:582
 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651
 alloc_skb include/linux/skbuff.h:1296 [inline]
 alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6394
 sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2784
 unix_dgram_sendmsg+0x464/0x1ca0 net/unix/af_unix.c:1974
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0xd5/0x180 net/socket.c:745
 __sys_sendto+0x225/0x310 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f3737a089b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffd1222db88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3737a089b5
RDX: 0000000000000088 RSI: 0000557fe5423880 RDI: 0000000000000003
RBP: 0000557fe541d2c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007f3737b96212 R14: 00007ffd1222dc88 R15: 0000000000000000
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.127 msecs