INFO: task kworker/u8:4:63 blocked for more than 143 seconds.
Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4 state:D stack:21400 pid:63 tgid:63 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: events_unbound flush_to_ldisc
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
commit_echoes drivers/tty/n_tty.c:740 [inline]
n_tty_receive_char+0x683/0xc30 drivers/tty/n_tty.c:1421
n_tty_receive_buf_standard+0x5e2/0x5150 drivers/tty/n_tty.c:1590
__receive_buf drivers/tty/n_tty.c:1624 [inline]
n_tty_receive_buf_common+0xab3/0x12f0 drivers/tty/n_tty.c:1723
tty_port_default_receive_buf+0x6e/0xa0 drivers/tty/tty_port.c:37
receive_buf drivers/tty/tty_buffer.c:445 [inline]
flush_to_ldisc+0x2c2/0x810 drivers/tty/tty_buffer.c:495
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
3 locks held by kworker/1:0/24:
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:2/36:
4 locks held by kworker/1:1/48:
3 locks held by kworker/u8:3/49:
6 locks held by kworker/u8:4/63:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90001557c60 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90001557c60 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff88801a0a10b8 (&buf->lock){+.+.}-{4:4}, at: flush_to_ldisc+0x38/0x810 drivers/tty/tty_buffer.c:467
#3: ffff88807d9ee0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x90 drivers/tty/tty_ldisc.c:263
#4: ffff88807d9ee2e8 (&tty->termios_rwsem){++++}-{4:4}, at: n_tty_receive_buf_common+0x84/0x12f0 drivers/tty/n_tty.c:1686
#5: ffffc900040fb380 (&ldata->output_lock){+.+.}-{4:4}, at: commit_echoes drivers/tty/n_tty.c:740 [inline]
#5: ffffc900040fb380 (&ldata->output_lock){+.+.}-{4:4}, at: n_tty_receive_char+0x683/0xc30 drivers/tty/n_tty.c:1421
3 locks held by kworker/u8:5/195:
4 locks held by kworker/1:2/976:
#0: ffff88801a081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90003cc7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90003cc7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2f4848 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf00 net/wireless/reg.c:2483
#3: ffff88805b0a8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6092 [inline]
#3: ffff88805b0a8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2471 [inline]
#3: ffff88805b0a8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x164/0xf00 net/wireless/reg.c:2486
6 locks held by kworker/0:2/978:
3 locks held by kworker/u8:6/1335:
3 locks held by kworker/R-ipv6_/3167:
#0: ffff88802f347948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88802f347948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000c1dfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000c1dfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2f4848 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f2f4848 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4738
2 locks held by kworker/R-bat_e/3397:
4 locks held by kworker/u8:7/3442:
3 locks held by kworker/u8:8/3453:
3 locks held by kworker/u8:9/3486:
1 lock held by klogd/5190:
2 locks held by udevd/5201:
3 locks held by crond/5573:
2 locks held by getty/5593:
#0: ffff88802fc410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5818:
2 locks held by udevd/5881:
4 locks held by kworker/1:3/5882:
2 locks held by kworker/0:4/5885:
2 locks held by kworker/1:4/5887:
2 locks held by kworker/1:5/5888:
4 locks held by kworker/1:6/5895:
4 locks held by kworker/0:7/5896:
1 lock held by udevd/5919:
3 locks held by udevd/5975:
3 locks held by kworker/u8:10/9053:
3 locks held by kworker/u8:11/9054:
2 locks held by syz-executor/9521:
2 locks held by kworker/1:9/9678:
2 locks held by kworker/0:9/9825:
2 locks held by syz.8.1063/10296:
6 locks held by syz.0.1069/10326:
3 locks held by kworker/u8:12/10331:
4 locks held by kworker/u8:13/10332:
3 locks held by kworker/u8:14/10333:
4 locks held by kworker/u8:15/10334:
3 locks held by sed/10335:
4 locks held by kworker/u8:16/10336:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 5895 Comm: kworker/1:6 Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
RIP: 0010:unwind_next_frame+0x1174/0x2390 arch/x86/kernel/unwind_orc.c:641
Code: 8b 14 24 4d 89 65 00 41 0f b6 04 2f 84 c0 0f 85 f9 0f 00 00 c6 03 00 4c 8b 64 24 10 4c 8b 7c 24 28 48 8b 44 24 40 0f b6 04 28 <84> c0 0f 85 8a 0d 00 00 41 0f b6 04 2f 84 c0 0f 85 a1 0d 00 00 0f
RSP: 0018:ffffc90000a07c98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000a07da0 RCX: 0000000000000000
RDX: ffffffff90928da4 RSI: 0000000000000000 RDI: ffffc90000a07dc8
RBP: dffffc0000000000 R08: ffffc90000a07dc7 R09: 0000000000000000
R10: ffffc90000a07db8 R11: fffff52000140fb9 R12: ffffc90000a08ee0
R13: ffffc90000a07db8 R14: ffffc90000a07d68 R15: 1ffffffff21251b4
FS: 0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555863845c8 CR3: 0000000033492000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4147 [inline]
slab_alloc_node mm/slub.c:4196 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203
skb_clone+0x212/0x3a0 net/core/skbuff.c:2056
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver+0x98/0x160 net/bridge/br_forward.c:190
br_flood+0x31a/0x6a0 net/bridge/br_forward.c:237
br_handle_frame_finish+0x146c/0x1950 net/bridge/br_input.c:220
br_nf_hook_thresh+0x3bf/0x490 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:314 [inline]
br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:282 [inline]
br_handle_frame+0x97f/0x14c0 net/bridge/br_input.c:433
__netif_receive_skb_core+0x10de/0x4180 net/core/dev.c:5773
__netif_receive_skb_one_core net/core/dev.c:5885 [inline]
__netif_receive_skb+0x72/0x380 net/core/dev.c:6000
process_backlog+0x60e/0x14f0 net/core/dev.c:6352
__napi_poll+0xc4/0x480 net/core/dev.c:7324
napi_poll net/core/dev.c:7388 [inline]
net_rx_action+0x6ea/0xdf0 net/core/dev.c:7510
handle_softirqs+0x283/0x870 kernel/softirq.c:579
do_softirq+0xec/0x180 kernel/softirq.c:480
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
local_bh_enable include/linux/bottom_half.h:33 [inline]
fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline]
kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:460
blake2s_compress+0x5f/0xd0 arch/x86/crypto/blake2s-glue.c:49
blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:32
hmac+0x288/0x330 drivers/net/wireguard/noise.c:332
kdf+0xde/0x270 drivers/net/wireguard/noise.c:360
mix_dh drivers/net/wireguard/noise.c:413 [inline]
wg_noise_handshake_consume_initiation+0x242/0x900 drivers/net/wireguard/noise.c:608
wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline]
wg_packet_handshake_receive_worker+0x5f2/0xfb0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245