[v6.1] INFO: rcu detected stall in packet_rcv

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fdb6fcb41cc7 Linux 6.1.176
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13408bae580000
kernel config: https://syzkaller.appspot.com/x/.config?x=acfbe65fbce84c0c
dashboard link: https://syzkaller.appspot.com/bug?extid=e561985955b0a1f311db
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8a12ae1ddcea/disk-fdb6fcb4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d0dd1b27df77/vmlinux-fdb6fcb4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/871bf60ea1f2/bzImage-fdb6fcb4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e56198...@syzkaller.appspotmail.com

cfg80211: failed to load regulatory.db
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P4432 0-.... } 4685 jiffies s: 1269 root: 0x1/T
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4432 Comm: syz.0.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14
Code: cc cc 48 c7 c7 40 e1 de 8a 48 c7 c6 80 e1 de 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 a1 2a d7 75 65 8b 0d 42 80 d7 75 f7 c1 ff ff ff 7f 74 1f
RSP: 0018:ffffc900000070c0 EFLAGS: 00000086
RAX: cf0b9694fb597600 RBX: ffff88805a0c9f60 RCX: 0000000000010100
RDX: ffff888019300000 RSI: ffffffff8adee180 RDI: ffffffff8adee140
RBP: 0000000000000001 R08: ffffffff8e200f6f R09: 1ffffffff1c401ed
R10: dffffc0000000000 R11: fffffbfff1c401ee R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8e2a640 R15: 0000000000000000
FS: 00007fdd666f76c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ff0fff8 CR3: 000000005bcc1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:721
trace_hrtimer_start include/trace/events/timer.h:203 [inline]
debug_activate kernel/time/hrtimer.c:503 [inline]
enqueue_hrtimer+0xbe/0x410 kernel/time/hrtimer.c:1097
__run_hrtimer kernel/time/hrtimer.c:1768 [inline]
__hrtimer_run_queues+0x63e/0xc90 kernel/time/hrtimer.c:1815
hrtimer_interrupt+0x399/0x980 kernel/time/hrtimer.c:1877
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:169 [inline]
RIP: 0010:unwind_next_frame+0x1a7/0x1fd0 arch/x86/kernel/unwind_orc.c:448
Code: 39 f8 0f 86 b0 16 00 00 44 89 f8 4c 8d 24 85 20 0b 3e 8f 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 23 18 00 00 45 8b 24 24 <44> 89 f8 ff c0 4c 8d 2c 85 20 0b 3e 8f 4c 89 e8 48 c1 e8 03 0f b6
RSP: 0018:ffffc900000074c0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000007568 RCX: ffffffff96bf9100
RDX: dffffc0000000000 RSI: 0000000000096079 RDI: 0000000000000001
RBP: dffffc0000000000 R08: ffffc90000007630 R09: 0000000000000006
R10: dffffc0000000000 R11: fffff52000000eb9 R12: 000000000014e648
R13: ffffc90000007a30 R14: ffffffff88288211 R15: 0000000000072882
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x200 mm/slub.c:3700
skb_free_head net/core/skbuff.c:762 [inline]
skb_release_data+0x5e9/0x7e0 net/core/skbuff.c:791
skb_release_all net/core/skbuff.c:856 [inline]
__kfree_skb net/core/skbuff.c:870 [inline]
consume_skb+0xa2/0x100 net/core/skbuff.c:1035
packet_rcv+0x166/0x1300 net/packet/af_packet.c:2280
__netif_receive_skb_one_core net/core/dev.c:5619 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5733
process_backlog+0x37c/0x710 net/core/dev.c:6061
__napi_poll+0xbb/0x460 net/core/dev.c:6628
napi_poll net/core/dev.c:6695 [inline]
net_rx_action+0x622/0xbc0 net/core/dev.c:6809
handle_softirqs+0x291/0x910 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0x80 kernel/kcov.c:313
Code: 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 90 48 8b 04 24 <65> 48 8b 15 c4 4a 80 7e 65 8b 0d c5 4a 80 7e 81 e1 00 01 ff 00 74
RSP: 0018:ffffc900046ce7b8 EFLAGS: 00000282
RAX: ffffffff818bccd3 RBX: 0000000000000000 RCX: cf0b9694fb597600
RDX: 1ffffffff1f40e00 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffffc900046ce8b8 R08: ffffffff8fa07008 R09: ffffffff8fa07018
R10: ffffffff8fa07010 R11: ffffffff8fa07003 R12: 0000000000000000
R13: ffff88807db0f018 R14: ffff88807db0f028 R15: 0000000000000001
__bpf_prog_run include/linux/filter.h:600 [inline]
bpf_prog_run include/linux/filter.h:614 [inline]
bpf_prog_run_array include/linux/bpf.h:1668 [inline]
trace_call_bpf+0x3f3/0x6b0 kernel/trace/bpf_trace.c:135
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
perf_trace_lock_acquire+0x342/0x3f0 include/trace/events/lock.h:24
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x452/0x4a0 kernel/locking/lockdep.c:5633
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
page_ext_get+0x3a/0x2a0 mm/page_ext.c:157
__set_page_owner+0x24/0x60 mm/page_owner.c:192
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
prep_new_page mm/page_alloc.c:2567 [inline]
get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
alloc_slab_page+0x5d/0x180 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2d0 mm/slub.c:1997
___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
slab_alloc mm/slub.c:3367 [inline]
__kmem_cache_alloc_lru mm/slub.c:3374 [inline]
kmem_cache_alloc+0x111/0x2f0 mm/slub.c:3383
__nf_conntrack_alloc+0x93/0x370 net/netfilter/nf_conntrack_core.c:1659
init_conntrack+0x23b/0x1190 net/netfilter/nf_conntrack_core.c:1752
resolve_normal_ct net/netfilter/nf_conntrack_core.c:1876 [inline]
nf_conntrack_in+0xd76/0x1830 net/netfilter/nf_conntrack_core.c:2031
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:614
nf_hook+0x224/0x390 include/linux/netfilter.h:257
__ip_local_out+0x49c/0x5d0 net/ipv4/ip_output.c:115
ip_local_out net/ipv4/ip_output.c:124 [inline]
ip_send_skb+0x48/0x1c0 net/ipv4/ip_output.c:1608
udp_send_skb+0xa4f/0x13f0 net/ipv4/udp.c:993
udp_sendmsg+0x1b46/0x23d0 net/ipv4/udp.c:1281
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519
___sys_sendmsg+0x2a2/0x360 net/socket.c:2573
__sys_sendmsg net/socket.c:2602 [inline]
__do_sys_sendmsg net/socket.c:2611 [inline]
__se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609
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: 0033:0x7fdd6579ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdd666f7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdd65a15fa0 RCX: 00007fdd6579ce59
RDX: 0000000000004004 RSI: 0000200000000380 RDI: 0000000000000012
RBP: 00007fdd65832e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdd65a16038 R14: 00007fdd65a15fa0 R15: 00007ffc53b3bba8
</TASK>


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