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

0 views
Skip to first unread message

syzbot

unread,
4:56 AM (9 hours ago) 4:56 AM
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 1989cd3d56e2 Linux 6.1.167
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=110135ca580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=df24ecf861bc428033e9
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3e0cf5574b81/disk-1989cd3d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0c1152de55b1/vmlinux-1989cd3d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3fe87e3166b1/bzImage-1989cd3d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+df24ec...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2670 jiffies s: 181317 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 27799 Comm: syz.4.7240 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline]
RIP: 0010:rcu_is_watching+0x2/0xa0 kernel/rcu/tree.c:720
Code: 8a e8 62 55 c1 08 48 c7 c7 a0 40 b3 8c 4c 89 f6 e8 83 9e cc 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 57 <41> 56 53 65 ff 05 6c ff 95 7e e8 df 69 c1 08 89 c3 83 f8 08 73 60
RSP: 0018:ffffc900001dff60 EFLAGS: 00000002
RAX: ffffffff81a90966 RBX: 0000000000000001 RCX: 0000000000010100
RDX: ffff88807cd73b80 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001e00b0 R08: ffffc900001e0037 R09: ffffc900001e0020
R10: dffffc0000000000 R11: fffff5200003c007 R12: 1ffff9200003c000
R13: ffffc900001e0100 R14: dffffc0000000000 R15: ffff88806387bc00
FS: 00007f5bbd8ad6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5bbd88cd58 CR3: 00000000351bc000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
rcu_read_unlock+0x1f/0xa0 include/linux/rcupdate.h:820
__perf_output_begin kernel/events/ring_buffer.c:263 [inline]
perf_output_begin_forward+0x7ea/0xa80 kernel/events/ring_buffer.c:272
__perf_event_output kernel/events/core.c:7732 [inline]
perf_event_output_forward+0x1ad/0x2f0 kernel/events/core.c:7750
__perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
perf_event_overflow kernel/events/core.c:9517 [inline]
perf_swevent_hrtimer+0x472/0x630 kernel/events/core.c:10967
__run_hrtimer kernel/time/hrtimer.c:1747 [inline]
__hrtimer_run_queues+0x50b/0xd50 kernel/time/hrtimer.c:1811
hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
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:kasan_quarantine_put+0x84/0x220 mm/kasan/quarantine.c:245
Code: e8 91 55 b5 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 00 67 03 00 45
RSP: 0018:ffffc900001e0808 EFLAGS: 00000206
RAX: f30585e924a90301 RBX: ffff88807df4bb40 RCX: f30585e924a90300
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20
RBP: ffff88807df4bb40 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000000
R13: ffffc900001e08a0 R14: 00000000000843c0 R15: 0000000000000282
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
kmem_cache_free+0xf7/0x290 mm/slub.c:3709
llc_rcv+0x755/0xc60 net/llc/llc_input.c:-1
__netif_receive_skb_list_ptype net/core/dev.c:5655 [inline]
__netif_receive_skb_list_core+0x6e6/0x750 net/core/dev.c:5698
__netif_receive_skb_list net/core/dev.c:5750 [inline]
netif_receive_skb_list_internal+0x93f/0xca0 net/core/dev.c:5841
netif_receive_skb_list+0x51/0x4e0 net/core/dev.c:5893
ieee80211_rx_napi+0x357/0x3d0 net/mac80211/rx.c:5342
ieee80211_rx include/net/mac80211.h:4849 [inline]
ieee80211_handle_queued_frames+0x105/0x1b0 net/mac80211/main.c:317
tasklet_action_common+0x2fe/0x4d0 kernel/softirq.c:827
handle_softirqs+0x2a1/0x930 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> df 0d 21 f7 65 8b 05 30 91 ca 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000cb97160 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: f30585e924a90300
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: 0000000000000001
RBP: ffffc9000cb971f8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000
R13: ffff888023c70000 R14: ffffffff96e55910 R15: 1ffff92001972e2c
__debug_check_no_obj_freed lib/debugobjects.c:988 [inline]
debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009
free_pages_prepare mm/page_alloc.c:1492 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x2a6/0x9a0 mm/page_alloc.c:3413
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508
free_slab mm/slub.c:2036 [inline]
discard_slab mm/slub.c:2042 [inline]
__unfreeze_partials+0x1a5/0x200 mm/slub.c:2591
put_cpu_partial+0x17c/0x250 mm/slub.c:2667
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+0x140/0x260 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc+0xa0/0x240 mm/slab_common.c:949
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
tomoyo_encode+0x27e/0x540 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x58e/0x5d0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x212/0x440 security/tomoyo/file.c:771
security_file_open+0x5e/0xa0 security/security.c:1682
do_dentry_open+0x305/0x10d0 fs/open.c:869
do_open fs/namei.c:3634 [inline]
path_openat+0x2635/0x2ee0 fs/namei.c:3791
do_filp_open+0x1f1/0x430 fs/namei.c:3818
do_sys_openat2+0x150/0x4b0 fs/open.c:1320
do_sys_open fs/open.c:1336 [inline]
__do_sys_openat fs/open.c:1352 [inline]
__se_sys_openat fs/open.c:1347 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1347
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: 0033:0x7f5bbc99c819
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:00007f5bbd8ad028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5bbcc16180 RCX: 00007f5bbc99c819
RDX: 00000000000026e1 RSI: 00002000000005c0 RDI: ffffffffffffff9c
RBP: 00007f5bbca32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5bbcc16218 R14: 00007f5bbcc16180 R15: 00007ffc451acb68
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup
Reply all
Reply to author
Forward
0 new messages