INFO: task syz.1.3980:23577 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3980 state:D stack:27416 pid:23577 tgid:23574 ppid:17745 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1522/0x51d0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1305
ksys_sync+0xc5/0x170 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c93d9aeb9
RSP: 002b:00007f2c94c41028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2c94016090 RCX: 00007f2c93d9aeb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2c94016090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c94016128 R14: 00007f2c94016090 R15: 00007ffd1d79be38
Showing all locks held in the system:
5 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/32:
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5575:
#0: ffff88802fe360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:5/16209:
1 lock held by udevd/18264:
#0: ffff888024fda358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.1.3980/23577:
#0: ffff888024fda358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305
1 lock held by syz-executor/23809:
#0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956
1 lock held by syz.8.4327/25003:
#0: ffff888024fda358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305
4 locks held by dhcpcd-run-hook/25723:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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:161 [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:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5806 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:dev_get_by_index_rcu+0x61/0x110 net/core/dev.c:981
Code: f7 e8 83 02 c5 f8 44 0f b6 fb 41 c1 e7 03 4d 03 3e 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 62 02 c5 f8 4d 8b 37 <4d> 85 f6 0f 94 c0 49 81 c6 48 fb ff ff 0f 94 c1 08 c1 74 07 e8 86
RSP: 0018:ffffc90000007188 EFLAGS: 00000246
RAX: 1ffff11006614400 RBX: 0000000000000000 RCX: ffff88803027db80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88802c878000
RBP: 0000000000000000 R08: ffff88803027db80 R09: 0000000000000002
R10: 00000000fffffff5 R11: ffffffff8a1c2c40 R12: dffffc0000000000
R13: ffffc900000072e0 R14: 0000000000000000 R15: ffff8880330a2000
FS: 000055557b28e500(0000) GS:ffff8881256f3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5819da6000 CR3: 0000000075e87000 CR4: 0000000000350ef0
Call Trace:
fib_select_path+0x221/0x450 net/ipv4/fib_semantics.c:2232
ip_route_output_key_hash_rcu+0x742/0x25d0 net/ipv4/route.c:2870
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2705
icmp_route_lookup+0x510/0xaa0 net/ipv4/icmp.c:507
__icmp_send+0xf64/0x1520 net/ipv4/icmp.c:930
icmp_send include/net/icmp.h:43 [inline]
__udp4_lib_rcv+0x185f/0x2620 net/ipv4/udp.c:2741
ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:207
ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6152 [inline]
__netif_receive_skb net/core/dev.c:6265 [inline]
process_backlog+0xaa3/0x1950 net/core/dev.c:6617
__napi_poll+0xae/0x340 net/core/dev.c:7681
napi_poll net/core/dev.c:7744 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7896
handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
lock_sock include/net/sock.h:1700 [inline]
tcp_recvmsg+0x1f2/0x7f0 net/ipv4/tcp.c:2926
inet_recvmsg+0x157/0x270 net/ipv4/af_inet.c:891
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x1a8/0x270 net/socket.c:1100
sock_read_iter+0x251/0x320 net/socket.c:1170
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x582/0xa70 fs/read_write.c:572
ksys_read+0x150/0x270 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98a31560d7
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffcc090a630 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055557b28e500 RCX: 00007f98a31560d7
RDX: 0000000000000004 RSI: 00007ffcc090a68c RDI: 0000000000000003
RBP: 00007ffcc090ab30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffcc090a68c R14: 00007ffcc090a720 R15: 0000000000000000