INFO: task syz-executor:4280 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22096 pid:4280 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
wb_wait_for_completion+0x16f/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x1c5/0xa10 fs/fs-writeback.c:2756
sync_filesystem+0x16d/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa20639da57
RSP: 002b:00007ffc612b72e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fa206432048 RCX: 00007fa20639da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc612b73a0
RBP: 00007ffc612b73a0 R08: 00007ffc612b83a0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc612b8430
R13: 00007fa206432048 R14: 00000000000182a1 R15: 00007ffc612b8470
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e790 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
4 locks held by kworker/u4:2/38:
#0:
ffff88814464d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90000af7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffff88807b8b0650 (sb_internal#3){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline]
#2: ffff88807b8b0650 (sb_internal#3){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x341/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698
#3: ffff88805532ed98 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline]
#3: ffff88805532ed98 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x368/0x1540 fs/xfs/libxfs/xfs_bmap.c:4698
2 locks held by getty/4027:
#0: ffff88802feb2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by syz-executor/4280:
#0: ffff88807b8b00e0 (&type->s_umount_key#59){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
#1: ffff8880243707d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff8880243707d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a9/0xa10 fs/fs-writeback.c:2754
2 locks held by kworker/1:19/4849:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000c627d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by syz-executor/5250:
#0: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by rm/5982:
2 locks held by modprobe/5983:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4678 Comm: kworker/1:15 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
RIP: 0010:nearest_obj include/linux/slub_def.h:162 [inline]
RIP: 0010:____kasan_slab_free+0xb1/0x1e0 mm/kasan/common.c:215
Code: 48 c1 f9 3f 48 21 c1 48 89 c8 48 c1 e0 06 48 bf 00 00 00 00 80 08 05 00 48 01 c7 48 89 d8 48 29 f8 45 8b 46 18 48 99 49 f7 f8 <48> 89 d8 48 29 d0 0f b7 71 2a 81 e6 ff 7f 00 00 ff ce 41 0f af f0
RSP: 0018:ffffc900057e7648 EFLAGS: 00000206
RAX: 0000000000000007 RBX: ffff88805715dc00 RCX: ffffea00015c5700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88805715c000
RBP: 0000000000000001 R08: 0000000000000400 R09: 1ffffffff215f265
R10: dffffc0000000000 R11: fffffbfff215f266 R12: 0000000000000000
R13: ffffc900057e76d8 R14: ffff888017441c80 R15: ffffffff81d2b6c6
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1159d61000 CR3: 000000002913a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
skb_free_head net/core/skbuff.c:762 [inline]
pskb_expand_head+0x3c4/0x12a0 net/core/skbuff.c:1880
skb_expand_head+0x1a9/0x380 net/core/skbuff.c:2005
ip6_finish_output2+0x128a/0x15d0 net/ipv6/ip6_output.c:74
ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
udp_tunnel6_xmit_skb+0x53a/0x970 net/ipv6/ip6_udp_tunnel.c:109
send6+0x5e6/0x920 drivers/net/wireguard/socket.c:152
wg_socket_send_skb_to_peer+0x10d/0x1c0 drivers/net/wireguard/socket.c:178
wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
wg_packet_tx_worker+0x1c4/0x7c0 drivers/net/wireguard/send.c:276
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295