[v6.6] INFO: rcu detected stall in perf_ioctl
0 views
Skip to first unread message
syzbot
Nov 13, 2025, 6:48:29 PM (6 days ago) Nov 13
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 0a805b6ea8cd Linux 6.6.116
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=119a497c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=501a45ff94a87100157e
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/743e52c6a2c2/disk-0a805b6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b7385817c222/vmlinux-0a805b6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/587fbfb2961d/bzImage-0a805b6e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+501a45...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-....: (10517 ticks this GP) idle=bd94/1/0x4000000000000000 softirq=50570/50572 fqs=4814
rcu: hardirqs softirqs csw/system
rcu: number: 1250647 0 0
rcu: cputime: 19343 33122 43 ==> 52470(ms)
rcu: (t=10500 jiffies g=68481 q=299 ncpus=2)
CPU: 1 PID: 13580 Comm: syz.6.2245 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline]
RIP: 0010:__local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:413
Code: 8a e8 9e 50 1d 09 65 66 8b 05 86 24 b2 7e 66 85 c0 75 54 bf 01 00 00 00 e8 67 db 09 00 e8 32 5f 3a 00 fb 65 8b 05 52 24 b2 7e <85> c0 75 05 e8 71 08 af ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc900001ef8c0 EFLAGS: 00000282
RAX: 0000000000000301 RBX: 0000000000000201 RCX: 07ab0dcf53c43800
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffffc900001ef950 R08: ffffffff90da85f7 R09: 1ffffffff21b50be
R10: dffffc0000000000 R11: fffffbfff21b50bf R12: ffffffff88b4a3c5
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200003df18
FS: 00007f2bb56e86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000254ed000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nf_nat_setup_info+0x17d5/0x26d0 net/netfilter/nf_nat_core.c:841
__nf_nat_alloc_null_binding net/netfilter/nf_nat_core.c:870 [inline]
nf_nat_alloc_null_binding net/netfilter/nf_nat_core.c:876 [inline]
nf_nat_inet_fn+0x837/0xbc0 net/netfilter/nf_nat_core.c:965
nf_nat_ipv6_fn+0x21b/0x2d0 net/netfilter/nf_nat_proto.c:937
nf_nat_ipv6_out+0x2e/0x380 net/netfilter/nf_nat_proto.c:966
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
nf_hook+0x215/0x370 include/linux/netfilter.h:259
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip6_output+0x272/0x3b0 net/ipv6/ip6_output.c:240
ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
udp_tunnel6_xmit_skb+0x5a4/0xa10 net/ipv6/ip6_udp_tunnel.c:109
geneve6_xmit_skb drivers/net/geneve.c:1088 [inline]
geneve_xmit+0x22a0/0x3090 drivers/net/geneve.c:1117
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3619 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635
__dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425
neigh_output include/net/neighbour.h:543 [inline]
ip6_finish_output2+0xe2e/0x1650 net/ipv6/ip6_output.c:141
dst_output include/net/dst.h:467 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513
addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254
Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 70 25 1c 09 e8 1b a3 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000371f498 EFLAGS: 00000282
RAX: 07ab0dcf53c43800 RBX: 0000000000000000 RCX: 07ab0dcf53c43800
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffffc9000371f4f0 R08: ffffffff90da85ff R09: 1ffffffff21b50bf
R10: dffffc0000000000 R11: fffffbfff21b50c0 R12: ffff88807a9b1e00
R13: dffffc0000000000 R14: ffff888025635a00 R15: ffff8880b8f3ccc8
context_switch kernel/sched/core.c:5383 [inline]
__schedule+0x14da/0x44d0 kernel/sched/core.c:6699
preempt_schedule_notrace+0xce/0x110 kernel/sched/core.c:6959
preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x3f8/0x410 kernel/locking/lockdep.c:5725
down_read_trylock+0x20a/0x370 kernel/locking/rwsem.c:1562
mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
get_mmap_lock_carefully mm/memory.c:5358 [inline]
lock_mm_and_find_vma+0x32/0x300 mm/memory.c:5418
do_user_addr_fault+0x36c/0x12e0 arch/x86/mm/fault.c:1345
handle_page_fault arch/x86/mm/fault.c:1465 [inline]
exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:do_strnlen_user lib/strnlen_user.c:37 [inline]
RIP: 0010:strnlen_user+0x8e/0x1c0 lib/strnlen_user.c:113
Code: b8 3a 34 fd 4c 89 f8 4c 01 f0 0f 88 24 01 00 00 4c 39 f0 0f 82 1b 01 00 00 48 89 1c 24 0f 01 cb 0f ae e8 4c 89 f0 48 83 e0 f8 <4c> 8b 28 45 89 f4 41 83 e4 07 42 8d 0c e5 00 00 00 00 48 c7 c0 ff
RSP: 0018:ffffc9000371fba0 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff88807a9b1e00
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000001000
RBP: ffffc9000371fed8 R08: ffff88807a9b1e00 R09: 000000000000000c
R10: 00000000c008240a R11: 0000000000000002 R12: 0000000000001000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000001000
strndup_user+0x1f/0x150 mm/util.c:248
perf_event_set_filter kernel/events/core.c:11133 [inline]
_perf_ioctl kernel/events/core.c:6003 [inline]
perf_ioctl+0x601/0x2440 kernel/events/core.c:6074
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2bb478f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2bb56e8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2bb49e5fa0 RCX: 00007f2bb478f6c9
RDX: 0000000000000000 RSI: 0000000040082406 RDI: 0000000000000003
RBP: 00007f2bb4811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2bb49e6038 R14: 00007f2bb49e5fa0 R15: 00007ffea9bad278
</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
syzbot found the following issue on:
HEAD commit: 0a805b6ea8cd Linux 6.6.116
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=119a497c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=501a45ff94a87100157e
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/743e52c6a2c2/disk-0a805b6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b7385817c222/vmlinux-0a805b6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/587fbfb2961d/bzImage-0a805b6e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+501a45...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-....: (10517 ticks this GP) idle=bd94/1/0x4000000000000000 softirq=50570/50572 fqs=4814
rcu: hardirqs softirqs csw/system
rcu: number: 1250647 0 0
rcu: cputime: 19343 33122 43 ==> 52470(ms)
rcu: (t=10500 jiffies g=68481 q=299 ncpus=2)
CPU: 1 PID: 13580 Comm: syz.6.2245 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline]
RIP: 0010:__local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:413
Code: 8a e8 9e 50 1d 09 65 66 8b 05 86 24 b2 7e 66 85 c0 75 54 bf 01 00 00 00 e8 67 db 09 00 e8 32 5f 3a 00 fb 65 8b 05 52 24 b2 7e <85> c0 75 05 e8 71 08 af ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc900001ef8c0 EFLAGS: 00000282
RAX: 0000000000000301 RBX: 0000000000000201 RCX: 07ab0dcf53c43800
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffffc900001ef950 R08: ffffffff90da85f7 R09: 1ffffffff21b50be
R10: dffffc0000000000 R11: fffffbfff21b50bf R12: ffffffff88b4a3c5
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200003df18
FS: 00007f2bb56e86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000254ed000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nf_nat_setup_info+0x17d5/0x26d0 net/netfilter/nf_nat_core.c:841
__nf_nat_alloc_null_binding net/netfilter/nf_nat_core.c:870 [inline]
nf_nat_alloc_null_binding net/netfilter/nf_nat_core.c:876 [inline]
nf_nat_inet_fn+0x837/0xbc0 net/netfilter/nf_nat_core.c:965
nf_nat_ipv6_fn+0x21b/0x2d0 net/netfilter/nf_nat_proto.c:937
nf_nat_ipv6_out+0x2e/0x380 net/netfilter/nf_nat_proto.c:966
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
nf_hook+0x215/0x370 include/linux/netfilter.h:259
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip6_output+0x272/0x3b0 net/ipv6/ip6_output.c:240
ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
udp_tunnel6_xmit_skb+0x5a4/0xa10 net/ipv6/ip6_udp_tunnel.c:109
geneve6_xmit_skb drivers/net/geneve.c:1088 [inline]
geneve_xmit+0x22a0/0x3090 drivers/net/geneve.c:1117
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3619 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635
__dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425
neigh_output include/net/neighbour.h:543 [inline]
ip6_finish_output2+0xe2e/0x1650 net/ipv6/ip6_output.c:141
dst_output include/net/dst.h:467 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513
addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254
Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 70 25 1c 09 e8 1b a3 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000371f498 EFLAGS: 00000282
RAX: 07ab0dcf53c43800 RBX: 0000000000000000 RCX: 07ab0dcf53c43800
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00
RBP: ffffc9000371f4f0 R08: ffffffff90da85ff R09: 1ffffffff21b50bf
R10: dffffc0000000000 R11: fffffbfff21b50c0 R12: ffff88807a9b1e00
R13: dffffc0000000000 R14: ffff888025635a00 R15: ffff8880b8f3ccc8
context_switch kernel/sched/core.c:5383 [inline]
__schedule+0x14da/0x44d0 kernel/sched/core.c:6699
preempt_schedule_notrace+0xce/0x110 kernel/sched/core.c:6959
preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x3f8/0x410 kernel/locking/lockdep.c:5725
down_read_trylock+0x20a/0x370 kernel/locking/rwsem.c:1562
mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
get_mmap_lock_carefully mm/memory.c:5358 [inline]
lock_mm_and_find_vma+0x32/0x300 mm/memory.c:5418
do_user_addr_fault+0x36c/0x12e0 arch/x86/mm/fault.c:1345
handle_page_fault arch/x86/mm/fault.c:1465 [inline]
exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:do_strnlen_user lib/strnlen_user.c:37 [inline]
RIP: 0010:strnlen_user+0x8e/0x1c0 lib/strnlen_user.c:113
Code: b8 3a 34 fd 4c 89 f8 4c 01 f0 0f 88 24 01 00 00 4c 39 f0 0f 82 1b 01 00 00 48 89 1c 24 0f 01 cb 0f ae e8 4c 89 f0 48 83 e0 f8 <4c> 8b 28 45 89 f4 41 83 e4 07 42 8d 0c e5 00 00 00 00 48 c7 c0 ff
RSP: 0018:ffffc9000371fba0 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff88807a9b1e00
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000001000
RBP: ffffc9000371fed8 R08: ffff88807a9b1e00 R09: 000000000000000c
R10: 00000000c008240a R11: 0000000000000002 R12: 0000000000001000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000001000
strndup_user+0x1f/0x150 mm/util.c:248
perf_event_set_filter kernel/events/core.c:11133 [inline]
_perf_ioctl kernel/events/core.c:6003 [inline]
perf_ioctl+0x601/0x2440 kernel/events/core.c:6074
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2bb478f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2bb56e8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2bb49e5fa0 RCX: 00007f2bb478f6c9
RDX: 0000000000000000 RSI: 0000000040082406 RDI: 0000000000000003
RBP: 00007f2bb4811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2bb49e6038 R14: 00007f2bb49e5fa0 R15: 00007ffea9bad278
</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