INFO: task syz.8.4619:21331 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.8.4619 state:D stack:25608 pid:21331 tgid:21330 ppid:20184 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
cgroup_lock_and_drain_offline+0x516/0x650 kernel/cgroup/cgroup.c:3248
cgroup1_get_tree+0xa2/0x8a0 kernel/cgroup/cgroup-v1.c:1265
vfs_get_tree+0x92/0x2a0 fs/super.c:1753
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3763 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3839
do_mount fs/namespace.c:4172 [inline]
__do_sys_mount fs/namespace.c:4388 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4365
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f461c1cce59
RSP: 002b:00007f461a426028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f461c445fa0 RCX: 00007f461c1cce59
RDX: 00002000000001c0 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f461c262d6f R08: 0000200000000180 R09: 0000000000000000
R10: 0000000002010042 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f461c446038 R14: 00007f461c445fa0 R15: 00007ffd64fcb088
Showing all locks held in the system:
4 locks held by rcuc/1/29:
#0: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#1: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6667
#2: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_internal net/core/dev.c:6390 [inline]
#2: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb+0x102/0xbf0 net/core/dev.c:6462
#3: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#3: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:242 [inline]
#3: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0 include/linux/netfilter.h:316
1 lock held by khungtaskd/38:
#0: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e1cabc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
4 locks held by kworker/1:2/822:
#0: ffff88813fe13938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc90005177c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffff888025d062a0 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_fb_dirty drivers/gpu/drm/drm_fb_helper.c:236 [inline]
#2: ffff888025d062a0 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0x125/0x720 drivers/gpu/drm/drm_fb_helper.c:275
#3: ffff8880260ba158 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x20/0x80 drivers/gpu/drm/drm_auth.c:435
2 locks held by getty/5374:
#0: ffff8880364e40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cae2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:6/5787:
#0: ffff88813fe13938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc900057a7c40 ((work_completion)(&(&hwstats->traffic_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
2 locks held by syz.9.5106/23185:
#0: ffff88802c9e6a60 (&dev->mutex#3){+.+.}-{4:4}, at: vb2_fop_read+0x101/0x360 drivers/media/common/videobuf2/videobuf2-v4l2.c:1210
#1: ffffffff8e311030 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffffffff8e311030 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294
2 locks held by syz-executor/23188:
#0: ffff88805f2c8d20 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
#0: ffff88805f2c8d20 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1931
#1: ffff888040e406d0 (&sb->s_type->i_lock_key#26){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#1: ffff888040e406d0 (&sb->s_type->i_lock_key#26){+.+.}-{3:3}, at: d_splice_alias_ops+0x80/0x3e0 fs/dcache.c:3152
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:119
nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: rcuc/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__unwind_start+0x43e/0x760 arch/x86/kernel/unwind_orc.c:756
Code: 18 4d 8b 24 24 41 80 3c 17 00 74 08 4c 89 f7 e8 68 c3 b8 00 48 8b 73 28 4c 8d 6b 20 4c 89 e7 48 89 da 4c 89 e9 e8 b2 96 f2 ff <85> c0 48 be 00 00 00 00 00 fc ff df 0f 84 84 00 00 00 89 2c 24 48
RSP: 0018:ffffc90000a3f188 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc90000a3f1e8 RCX: 0000000000000001
RDX: 0000000000000002 RSI: ffffc90000a40000 RDI: ffffc90000a3f188
RBP: ffffc90000a3f201 R08: ffffc90000a3f201 R09: 0000000000000000
R10: ffffc90000a3f1e8 R11: fffff52000147e49 R12: ffffc90000a3f188
R13: ffffc90000a3f208 R14: ffffc90000a3f210 R15: 1ffff92000147e42
FS: 0000000000000000(0000) GS:ffff888125d94000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd0105adf0 CR3: 0000000070114000 CR4: 00000000003526f0
DR0: 0000000000000003 DR1: 8000000000000000 DR2: 0000000000000001
DR3: 0000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
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+0x46/0x50 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:2700 [inline]
slab_free mm/slub.c:6284 [inline]
kmem_cache_free+0x187/0x6c0 mm/slub.c:6411
kfree_skb_reason include/linux/skbuff.h:1321 [inline]
kfree_skb include/linux/skbuff.h:1330 [inline]
ip6_mc_input+0x8de/0xbd0 net/ipv6/ip6_input.c:638
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6317 [inline]
process_backlog+0x3ce/0xc60 net/core/dev.c:6668
__napi_poll+0xab/0x550 net/core/dev.c:7735
napi_poll net/core/dev.c:7798 [inline]
net_rx_action+0x696/0xe00 net/core/dev.c:7955
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
__local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_do_batch kernel/rcu/tree.c:2636 [inline]
rcu_core kernel/rcu/tree.c:2869 [inline]
rcu_cpu_kthread+0x9e8/0x1470 kernel/rcu/tree.c:2957
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 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