INFO: task syz.6.1107:11742 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.6.1107 state:D stack:27368 pid:11742 tgid:11726 ppid:6930 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1840/0x57a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
__flush_work+0xa63/0xca0 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+0x230/0x3f0 net/9p/trans_fd.c:840
p9_client_create+0x8a6/0xc60 net/9p/client.c:937
v9fs_session_init+0x46/0xc20 fs/9p/v9fs.c:446
v9fs_get_tree+0xbd/0xac0 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3761 [inline]
do_new_mount+0x319/0xdc0 fs/namespace.c:3837
do_mount fs/namespace.c:4170 [inline]
__do_sys_mount fs/namespace.c:4386 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4363
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: 0033:0x7fc37d99ce59
RSP: 002b:00007fc37e812028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc37dc16180 RCX: 00007fc37d99ce59
RDX: 0000200000004500 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007fc37da32d6f R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc37dc16218 R14: 00007fc37dc16180 R15: 00007ffcaa699578
Showing all locks held in the system:
1 lock held by khungtaskd/32:
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by syslogd/4974:
#0: ffff8880b863b0e0 (&rq->__lock){-.-.}-{2:2}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2584
1 lock held by klogd/4981:
2 locks held by getty/5381:
#0: ffff888036e9e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1380 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:4/5737:
#0: ffff88813fe3f140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88813fe3f140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
#1: ffffc90002fa7c40 (p9_poll_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#1: ffffc90002fa7c40 (p9_poll_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3397
1 lock held by udevd/6021:
#0: ffff888023094ce8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
#0: ffff888023094ce8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_read_iter+0x2df/0x420 block/fops.c:854
1 lock held by syz-executor/9465:
6 locks held by syz.9.1473/13409:
1 lock held by syz.9.1473/13452:
1 lock held by syz.4.1481/13431:
#0: ffff88807e4b9bb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#0: ffff88807e4b9bb8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
1 lock held by syz.4.1481/13435:
1 lock held by syz.1.1482/13437:
#0: ffff8880625200d8 (&type->s_umount_key#54/1){+.+.}-{4:4}, at: alloc_super+0x283/0xa60 fs/super.c:345
1 lock held by syz.8.1483/13438:
=============================================
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 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+0x389/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4974 Comm: syslogd 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:rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:838 [inline]
RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
RIP: 0010:unwind_next_frame+0x88/0x2550 arch/x86/kernel/unwind_orc.c:495
Code: 49 c1 ef 03 43 0f b6 04 27 84 c0 0f 85 bd 1b 00 00 41 8b 06 85 c0 0f 84 46 02 00 00 89 44 24 5c 4c 89 6c 24 68 e8 28 79 34 00 <4c> 8d 2d 00 00 00 00 48 c7 c7 80 c7 95 8e 31 f6 31 d2 b9 02 00 00
RSP: 0018:ffffc900039074e0 EFLAGS: 00000283
RAX: 0000000000000001 RBX: ffffffff8241a200 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff8241a200 RDI: ffffc900039075c0
RBP: 1ffff92000720eb8 R08: ffffc90003907650 R09: 0000000000000008
R10: dffffc0000000000 R11: ffffffff81b071b0 R12: dffffc0000000000
R13: ffffc90003907e20 R14: ffffc90003907588 R15: 1ffff92000720eb1
FS: 00007ff549fa9c80(0000) GS:ffff8881252b9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd6b2e39ff8 CR3: 0000000033406000 CR4: 0000000000350ef0
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6251 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6378
__unix_dgram_recvmsg+0x9e1/0xd70 net/unix/af_unix.c:2669
sock_recvmsg_nosec net/socket.c:1138 [inline]
sock_recvmsg+0x172/0x1b0 net/socket.c:1160
sock_read_iter+0x246/0x320 net/socket.c:1230
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x595/0xa80 fs/read_write.c:574
ksys_read+0x150/0x270 fs/read_write.c:717
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: 0033:0x7ff54a0f9407
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:00007ffc6b419150 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007ff549fa9c80 RCX: 00007ff54a0f9407
RDX: 00000000000000ff RSI: 0000556d44924950 RDI: 0000000000000000
RBP: 0000556d44924910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000556d449249a8
R13: 0000000000000000 R14: 0000556d44924950 R15: 0000556d4073bd98