INFO: task syz.9.5802:22873 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.5802 state:D stack:26200 pid:22873 ppid:21676 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
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
sync_bdevs+0x1ab/0x320 block/bdev.c:1071
ksys_sync+0xc2/0x170 fs/sync.c:105
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0ba6d9c799
RSP: 002b:00007f0ba7c08028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f0ba7015fa0 RCX: 00007f0ba6d9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0ba7015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0ba7016038 R14: 00007f0ba7015fa0 R15: 00007ffceddbc9f8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2dfb0 (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: ffffffff8cb2e7d0 (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/28:
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
5 locks held by kworker/u4:3/46:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90000b77d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd39b10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594
#3: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xee/0xa80 net/core/dev.c:11515
#4: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#4: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
1 lock held by dhcpcd/3932:
#0: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305
2 locks held by getty/4032:
#0: ffff88802f812098 (&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
1 lock held by udevd/4271:
#0: ffff888023f864c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
3 locks held by kworker/0:7/4351:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004567d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
1 lock held by udevd/4407:
#0: ffff8880245ab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
3 locks held by kworker/u4:7/4464:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900032a7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
2 locks held by kworker/1:9/9008:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000dae7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/1:10/9010:
#0: ffff88814d648538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc9000e10fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4672
2 locks held by dhcpcd/21627:
#0: ffff8880716a6e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff8880716a6e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff8880716a6e10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1399
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb332f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz.9.5802/22873:
#0: ffff8880245ab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1071
1 lock held by syz.8.6692/25672:
#0: ffff8880245ab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1071
1 lock held by syz-executor/26449:
#0: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6147
2 locks held by syz.4.6974/26583:
#0: ffffffff8dda6c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860
#1: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5b/0x930 net/wireless/nl80211.c:16369
2 locks held by syz.6.6977/26589:
#0: ffffffff8dda6c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860
#1: ffffffff8dd469e8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5b/0x930 net/wireless/nl80211.c:16369
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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: 3626 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unwind_next_frame+0x178a/0x20b0 arch/x86/kernel/unwind_orc.c:621
Code: 49 bd 00 00 00 00 00 fc ff df 48 8b 44 24 18 42 0f b6 04 28 84 c0 0f 85 29 06 00 00 8b 84 24 8c 00 00 00 39 03 48 8b 7c 24 58 <0f> 85 e6 00 00 00 48 8b 44 24 50 42 80 3c 28 00 74 05 e8 2f 2d 9a
RSP: 0018:ffffc900032b72f0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffc900032b73c8 RCX: 0000000000000001
RDX: ffffc900032b7408 RSI: dffffc0000000000 RDI: ffffc900032b7400
RBP: ffffffff8ea9e5c2 R08: ffffc900032b7888 R09: ffffc900032b7418
R10: dffffc0000000000 R11: fffff52000656e85 R12: ffffffff8ea9e5c1
R13: dffffc0000000000 R14: ffffc900032b7418 R15: ffffffff8ea9e5c0
FS: 00007f8029541c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056030103e660 CR3: 000000007e704000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
save_stack+0x121/0x230 mm/page_owner.c:127
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1486 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
slab_alloc_node mm/slub.c:3359 [inline]
kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404
__alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1303 [inline]
alloc_skb_with_frags+0xa7/0x710 net/core/skbuff.c:6164
sock_alloc_send_pskb+0x87f/0x9a0 net/core/sock.c:2755
unix_dgram_sendmsg+0x539/0x16e0 net/unix/af_unix.c:1945
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
__sys_sendto+0x497/0x650 net/socket.c:2152
__do_sys_sendto net/socket.c:2164 [inline]
__se_sys_sendto net/socket.c:2160 [inline]
__x64_sys_sendto+0xda/0xf0 net/socket.c:2160
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8029691407
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:00007ffd3c2f8f70 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f8029541c80 RCX: 00007f8029691407
RDX: 0000000000000049 RSI: 00007ffd3c2f90b0 RDI: 0000000000000003
RBP: 00007ffd3c2f94e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffd3c2f94f8
R13: 00007ffd3c2f90b0 R14: 000000000000002e R15: 00007ffd3c2f90b0