INFO: task syz.2.1245:15867 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1245 state:D stack:25864 pid:15867 tgid:15866 ppid:5597 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1502 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1576
__super_lock fs/super.c:60 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:122
__iterate_supers+0x120/0x240 fs/super.c:866
quota_sync_all fs/quota/quota.c:69 [inline]
__do_sys_quotactl fs/quota/quota.c:938 [inline]
__se_sys_quotactl+0x3a0/0x9a0 fs/quota/quota.c:917
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: 0033:0x7f3e3fd1ce59
RSP: 002b:00007f3e3df76028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f3e3ff95fa0 RCX: 00007f3e3fd1ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007f3e3fdb2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3e3ff96038 R14: 00007f3e3ff95fa0 R15: 00007ffc543ebf58
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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+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: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:229 [inline]
RIP: 0010:unwind_next_frame+0x21d/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: b6 04 20 84 c0 4c 89 e3 0f 85 66 1d 00 00 45 8b 6d 00 44 89 f8 ff c0 4c 8d 24 85 10 ae 97 90 4c 89 e0 48 c1 e8 03 0f b6 04 18 <84> c0 0f 85 66 1d 00 00 45 8b 04 24 41 ff c0 4a 8d 04 6d 00 00 00
RSP: 0000:ffffc90000a3e848 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000080000000
RDX: 00000000000a1c9e RSI: ffffffff8b877e00 RDI: ffffffff8b877dc0
RBP: ffffffff816d2962 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90000a3e998 R11: fffff52000147d35 R12: ffffffff909962b8
R13: 0000000000015215 R14: ffffc90000a3e948 R15: 0000000000006d29
FS: 0000000000000000(0000) GS:ffff888126490000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fec55e94000 CR3: 0000000056a32000 CR4: 00000000003526f0
Call Trace:
__unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
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+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+0x187/0x6c0 mm/slub.c:6378
kfree_skb_reason include/linux/skbuff.h:1324 [inline]
kfree_skb include/linux/skbuff.h:1333 [inline]
ip6_mc_input+0x909/0xbc0 net/ipv6/ip6_input.c:638
ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
netif_receive_skb_internal net/core/dev.c:6401 [inline]
netif_receive_skb+0x278/0xbf0 net/core/dev.c:6460
NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318
br_handle_frame_finish+0x1115/0x1930 net/bridge/br_input.c:-1
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x1275/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6089
__netif_receive_skb_one_core net/core/dev.c:6200 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0x351/0xc50 net/core/dev.c:6666
__napi_poll+0xae/0x550 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0x621/0xd70 net/core/dev.c:7953
handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x57c/0xa80 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