INFO: task udevd:9698 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22776 pid:9698 tgid:9698 ppid:4987 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0x889/0x1150 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2356
blk_mq_dispatch_list+0xd11/0xe10 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x45f/0x540 block/blk-mq.c:2966
__blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1273
blk_finish_plug block/blk-core.c:1300 [inline]
__submit_bio+0x465/0x560 block/blk-core.c:690
__submit_bio_noacct_mq block/blk-core.c:763 [inline]
submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:797
bh_submit fs/buffer.c:1239 [inline]
block_read_full_folio+0x581/0x810 fs/buffer.c:2449
filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2513
do_read_cache_folio+0x354/0x590 mm/filemap.c:4118
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:357
check_partition block/partitions/core.c:143 [inline]
blk_add_partitions block/partitions/core.c:591 [inline]
bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695
blkdev_get_whole+0x372/0x510 block/bdev.c:751
bdev_open+0x324/0xd70 block/bdev.c:960
blkdev_open+0x461/0x600 block/fops.c:672
do_dentry_open+0x816/0x1380 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4700 [inline]
path_openat+0x2e44/0x3830 fs/namei.c:4859
do_file_open+0x23e/0x4a0 fs/namei.c:4888
do_sys_openat2+0x115/0x200 fs/open.c:1395
do_sys_open fs/open.c:1401 [inline]
__do_sys_openat fs/open.c:1417 [inline]
__se_sys_openat fs/open.c:1412 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1412
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9d4fea7407
RSP: 002b:00007ffe4eae5e80 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9d505be880 RCX: 00007f9d4fea7407
RDX: 00000000000a0800 RSI: 000055b32d431e40 RDI: ffffffffffffff9c
RBP: 000055b32d422910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055b32d4459d0
R13: 000055b32d430190 R14: 0000000000000000 R15: 000055b32d4459d0
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 26942 Comm: syz.4.5832 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:skb_recv_datagram+0x158/0x180 net/core/datagram.c:317
Code: df e8 7c a2 ba f8 eb 93 e8 05 4e 4f f8 eb 13 e8 fe 4d 4f f8 eb 0c e8 f7 4d 4f f8 eb 05 e8 f0 4d 4f f8 65 48 8b 05 e8 97 c3 09 <48> 3b 44 24 18 75 17 4c 89 f8 48 83 c4 20 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc900046cf728 EFLAGS: 00000293
RAX: 40af505c36218c00 RBX: ffffc900046cf820 RCX: ffff888032ce9f00
RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 00000000ffffffff
RBP: 1ffff920008d9f04 R08: ffffffff903116f7 R09: 1ffffffff20622de
R10: dffffc0000000000 R11: fffffbfff20622df R12: dffffc0000000000
R13: 7fffffffffffffff R14: ffff88804ecad280 R15: 0000000000000000
FS: 00007f9792ea16c0(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000d80030 CR3: 00000000355a8000 CR4: 00000000003526f0
Call Trace:
ping_recvmsg+0x110/0x1010 net/ipv4/ping.c:859
sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1126
____sys_recvmsg+0x3e3/0x4a0 net/socket.c:2902
___sys_recvmsg+0x213/0x5a0 net/socket.c:2946
do_recvmmsg+0x31a/0x7f0 net/socket.c:3041
__sys_recvmmsg net/socket.c:3115 [inline]
__do_sys_recvmmsg net/socket.c:3138 [inline]
__se_sys_recvmmsg net/socket.c:3131 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3131
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9791f9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9792ea1028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f9792216180 RCX: 00007f9791f9ce59
RDX: 000000000400023c RSI: 00002000000055c0 RDI: 000000000000000b
RBP: 00007f9792032e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000300 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9792216218 R14: 00007f9792216180 R15: 00007ffcf96ab298