INFO: task syz.3.335:7237 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.335 state:D stack:27960 pid:7237 tgid:7236 ppid:5621 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__flush_work+0x7c7/0xcb0 kernel/workqueue.c:4366
p9_mux_poll_stop net/9p/trans_fd.c:140 [inline]
p9_conn_destroy net/9p/trans_fd.c:804 [inline]
p9_fd_close+0x299/0x5a0 net/9p/trans_fd.c:840
p9_client_create+0x678/0xd40 net/9p/client.c:937
v9fs_session_init+0x3c/0xd20 fs/9p/v9fs.c:446
v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x320 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3758 [inline]
do_new_mount fs/namespace.c:3834 [inline]
path_mount+0x7d0/0x23d0 fs/namespace.c:4154
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount fs/namespace.c:4360 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4360
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74af99ce59
RSP: 002b:00007f74b083f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f74afc15fa0 RCX: 00007f74af99ce59
RDX: 0000200000000040 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f74afa32d6f R08: 00002000000001c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74afc16038 R14: 00007f74afc15fa0 R15: 00007ffcc1798028
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/1:3/5349:
#0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289
#1: ffffc900024f7d08 (p9_poll_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290
2 locks held by getty/5377:
#0: ffff88803920f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
5 locks held by kworker/0:6/5799:
4 locks held by kworker/u8:25/5880:
2 locks held by syz.0.804/9440:
2 locks held by syz.7.805/9442:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4972 Comm: klogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lock_is_held_type+0xe2/0x140 kernel/locking/lockdep.c:5942
Code: b6 c0 48 c7 c7 9a a6 ee 8d 89 44 24 04 e8 36 19 00 00 ba ff ff ff ff 65 0f c1 15 f1 55 80 08 83 fa 01 8b 44 24 04 75 2d 9c 5a <80> e6 02 75 47 41 f7 c5 00 02 00 00 74 01 fb 48 83 c4 08 5b 5d 41
RSP: 0018:ffffc900061f7830 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8e7e5500 RCX: 0000000000000001
RDX: 0000000000000046 RSI: ffffffff8deea69a RDI: ffffffff8c1c4780
RBP: ffff88803720ca80 R08: 0000000000000001 R09: 00000000000000ae
R10: 0000000000000200 R11: 0000000000000000 R12: 00000000ffffffff
R13: 0000000000000246 R14: ffff88801febf3c0 R15: 0000000000400cc0
FS: 00007f9ebcd8ec80(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c00ff8 CR3: 00000000337ac000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
__might_resched+0x248/0x330 kernel/sched/core.c:9125
might_alloc include/linux/sched/mm.h:323 [inline]
slab_pre_alloc_hook mm/slub.c:4521 [inline]
slab_alloc_node mm/slub.c:4876 [inline]
kmem_cache_alloc_node_noprof+0x367/0x6f0 mm/slub.c:4951
__alloc_skb+0x140/0x710 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1385 [inline]
alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6766
sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:3002
unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2141
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
__sys_sendto+0x468/0x4b0 net/socket.c:2265
__do_sys_sendto net/socket.c:2272 [inline]
__se_sys_sendto net/socket.c:2268 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9ebcede407
Code: 48 89 fa 4c 89 df e8 38 aa 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:00007ffd111fa5f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f9ebcd8ec80 RCX: 00007f9ebcede407
RDX: 0000000000000051 RSI: 00007ffd111fa730 RDI: 0000000000000003
RBP: 00007ffd111fab60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffd111fab78
R13: 00007ffd111fa730 R14: 0000000000000036 R15: 00007ffd111fa730