[v5.15] INFO: rcu detected stall in inet_rtm_newroute
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syzbot
Jan 31, 2026, 3:30:31 PM (2 days ago) Jan 31
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 9eec9a14ee10 Linux 5.15.198
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16e8672a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=e33972907a9d9c74da7b
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/6bf27c1311e7/disk-9eec9a14.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/20b573bab166/vmlinux-9eec9a14.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f5ff7bd08305/bzImage-9eec9a14.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e33972...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (16 ticks this GP) idle=351/1/0x4000000000000000 softirq=44459/44459 fqs=0
(detected by 1, t=10502 jiffies, g=59225, q=1702)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15122 Comm: syz.4.3616 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_compound_head include/linux/page-flags.h:196 [inline]
RIP: 0010:PageSlab include/linux/page-flags.h:356 [inline]
RIP: 0010:kasan_record_aux_stack+0x17/0x100 mm/kasan/generic.c:338
Code: 0f 1f 00 48 89 f2 be f8 00 00 00 e9 23 0e 4c 02 0f 1f 00 41 56 53 48 89 fb e8 a5 eb ff ff 48 85 c0 0f 84 a7 00 00 00 48 89 c7 <48> 8b 40 08 48 89 f9 a8 01 0f 85 99 00 00 00 48 83 39 ff 48 8b 47
RSP: 0018:ffffc90000007010 EFLAGS: 00000086
RAX: ffffea0002e40ec0 RBX: ffff8880b903b1f0 RCX: ffffea0002e40ec8
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: ffffea0002e40ec0
RBP: 0000000000000000 R08: ffff8880b903b1fb R09: 1ffff1101720763f
R10: dffffc0000000000 R11: ffffed1017207640 R12: 0000000000000000
R13: dffffc0000000001 R14: 0000000000000000 R15: ffff8880b903b1f8
FS: 00007f528d07e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c342428 CR3: 00000000543a9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
irq_work_queue_on+0xf1/0x220 kernel/irq_work.c:101
rcu_read_unlock_special+0x37b/0x4a0 kernel/rcu/tree_plugin.h:667
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
__perf_event_output kernel/events/core.c:7813 [inline]
perf_event_output_forward+0x255/0x2e0 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 c2 ef 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 5039e980bf158900 RBX: 1ffff92000000ef8 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: ffffc90000007880 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
netif_receive_skb_list_internal+0x961/0xbd0 net/core/dev.c:5760
gro_normal_list net/core/dev.c:5913 [inline]
napi_complete_done+0x378/0x850 net/core/dev.c:6651
virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
virtnet_poll+0x955/0xf40 drivers/net/virtio_net.c:1624
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7232
handle_softirqs+0x339/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
</IRQ>
<TASK>
asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c 80 67 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 b6 eb 70 08 e8 41 e0 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc9000309ed48 EFLAGS: 00000286
RAX: 5039e980bf158900 RBX: ffff8880b903a340 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 1ffff11017207613 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fib_create_info+0x1221/0x24f0 net/ipv4/fib_semantics.c:1646
Code: 00 74 6d e8 a1 8d 00 f9 4c 8b 3c 24 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 28 92 45 f9 4d 89 37 41 be ea ff ff ff <48> 8d 7b 44 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 92 10 00
RSP: 0018:ffffc9000309f128 EFLAGS: 00000287
RAX: ffffffff88788faf RBX: ffff888141f96a00 RCX: 0000000000080000
RDX: ffffc9000ce81000 RSI: 000000000000cf38 RDI: 000000000000cf39
RBP: dffffc0000000000 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffc9000309f3a0
R13: ffffc9000309f3a4 R14: 00000000ffffffea R15: 1ffff92000613e74
fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212
inet_rtm_newroute+0x147/0x230 net/ipv4/fib_frontend.c:905
rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmsg net/socket.c:2528 [inline]
__do_sys_sendmsg net/socket.c:2537 [inline]
__se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f528ee22eb9
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:00007f528d07e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f528f09dfa0 RCX: 00007f528ee22eb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007f528ee90c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f528f09e038 R14: 00007f528f09dfa0 R15: 00007ffcaa9289d8
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g59225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=22026
rcu: rcu_preempt kthread starved for 10502 jiffies! g59225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27184 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15122 Comm: syz.4.3616 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0xe7/0x7d10 kernel/locking/lockdep.c:4882
Code: 2d 9e 67 a5 7e 48 c7 c0 44 0c 8a 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 cb 65 00 00 83 3d 03 04 2d 0c 00 0f 84 a8 27 00 00 <83> 3d 92 d4 c1 0a 00 74 29 48 89 d8 48 c1 e8 03 42 80 3c 00 00 74
RSP: 0018:ffffc90000006c80 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffffffff8c31eaa0 RCX: 1ffff92000000db4
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c31eaa0
RBP: ffffc90000006ed0 R08: dffffc0000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1b13b16 R12: 0000000000000000
R13: ffff88802282bb80 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f528d07e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c342428 CR3: 00000000543a9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__perf_output_begin kernel/events/ring_buffer.c:163 [inline]
perf_output_begin_forward+0xa5/0xa40 kernel/events/ring_buffer.c:271
__perf_event_output kernel/events/core.c:7804 [inline]
perf_event_output_forward+0x19b/0x2e0 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 c2 ef 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 5039e980bf158900 RBX: 1ffff92000000ef8 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: ffffc90000007880 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
netif_receive_skb_list_internal+0x961/0xbd0 net/core/dev.c:5760
gro_normal_list net/core/dev.c:5913 [inline]
napi_complete_done+0x378/0x850 net/core/dev.c:6651
virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
virtnet_poll+0x955/0xf40 drivers/net/virtio_net.c:1624
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7232
handle_softirqs+0x339/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
</IRQ>
<TASK>
asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c 80 67 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 b6 eb 70 08 e8 41 e0 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc9000309ed48 EFLAGS: 00000286
RAX: 5039e980bf158900 RBX: ffff8880b903a340 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 1ffff11017207613 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fib_create_info+0x1221/0x24f0 net/ipv4/fib_semantics.c:1646
Code: 00 74 6d e8 a1 8d 00 f9 4c 8b 3c 24 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 28 92 45 f9 4d 89 37 41 be ea ff ff ff <48> 8d 7b 44 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 92 10 00
RSP: 0018:ffffc9000309f128 EFLAGS: 00000287
RAX: ffffffff88788faf RBX: ffff888141f96a00 RCX: 0000000000080000
RDX: ffffc9000ce81000 RSI: 000000000000cf38 RDI: 000000000000cf39
RBP: dffffc0000000000 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffc9000309f3a0
R13: ffffc9000309f3a4 R14: 00000000ffffffea R15: 1ffff92000613e74
fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212
inet_rtm_newroute+0x147/0x230 net/ipv4/fib_frontend.c:905
rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmsg net/socket.c:2528 [inline]
__do_sys_sendmsg net/socket.c:2537 [inline]
__se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f528ee22eb9
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:00007f528d07e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f528f09dfa0 RCX: 00007f528ee22eb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007f528ee90c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f528f09e038 R14: 00007f528f09dfa0 R15: 00007ffcaa9289d8
</TASK>
---
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syzbot found the following issue on:
HEAD commit: 9eec9a14ee10 Linux 5.15.198
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16e8672a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=e33972907a9d9c74da7b
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/6bf27c1311e7/disk-9eec9a14.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/20b573bab166/vmlinux-9eec9a14.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f5ff7bd08305/bzImage-9eec9a14.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e33972...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (16 ticks this GP) idle=351/1/0x4000000000000000 softirq=44459/44459 fqs=0
(detected by 1, t=10502 jiffies, g=59225, q=1702)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15122 Comm: syz.4.3616 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_compound_head include/linux/page-flags.h:196 [inline]
RIP: 0010:PageSlab include/linux/page-flags.h:356 [inline]
RIP: 0010:kasan_record_aux_stack+0x17/0x100 mm/kasan/generic.c:338
Code: 0f 1f 00 48 89 f2 be f8 00 00 00 e9 23 0e 4c 02 0f 1f 00 41 56 53 48 89 fb e8 a5 eb ff ff 48 85 c0 0f 84 a7 00 00 00 48 89 c7 <48> 8b 40 08 48 89 f9 a8 01 0f 85 99 00 00 00 48 83 39 ff 48 8b 47
RSP: 0018:ffffc90000007010 EFLAGS: 00000086
RAX: ffffea0002e40ec0 RBX: ffff8880b903b1f0 RCX: ffffea0002e40ec8
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: ffffea0002e40ec0
RBP: 0000000000000000 R08: ffff8880b903b1fb R09: 1ffff1101720763f
R10: dffffc0000000000 R11: ffffed1017207640 R12: 0000000000000000
R13: dffffc0000000001 R14: 0000000000000000 R15: ffff8880b903b1f8
FS: 00007f528d07e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c342428 CR3: 00000000543a9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
irq_work_queue_on+0xf1/0x220 kernel/irq_work.c:101
rcu_read_unlock_special+0x37b/0x4a0 kernel/rcu/tree_plugin.h:667
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
__perf_event_output kernel/events/core.c:7813 [inline]
perf_event_output_forward+0x255/0x2e0 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 c2 ef 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 5039e980bf158900 RBX: 1ffff92000000ef8 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: ffffc90000007880 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
netif_receive_skb_list_internal+0x961/0xbd0 net/core/dev.c:5760
gro_normal_list net/core/dev.c:5913 [inline]
napi_complete_done+0x378/0x850 net/core/dev.c:6651
virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
virtnet_poll+0x955/0xf40 drivers/net/virtio_net.c:1624
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7232
handle_softirqs+0x339/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
</IRQ>
<TASK>
asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c 80 67 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 b6 eb 70 08 e8 41 e0 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc9000309ed48 EFLAGS: 00000286
RAX: 5039e980bf158900 RBX: ffff8880b903a340 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 1ffff11017207613 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fib_create_info+0x1221/0x24f0 net/ipv4/fib_semantics.c:1646
Code: 00 74 6d e8 a1 8d 00 f9 4c 8b 3c 24 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 28 92 45 f9 4d 89 37 41 be ea ff ff ff <48> 8d 7b 44 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 92 10 00
RSP: 0018:ffffc9000309f128 EFLAGS: 00000287
RAX: ffffffff88788faf RBX: ffff888141f96a00 RCX: 0000000000080000
RDX: ffffc9000ce81000 RSI: 000000000000cf38 RDI: 000000000000cf39
RBP: dffffc0000000000 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffc9000309f3a0
R13: ffffc9000309f3a4 R14: 00000000ffffffea R15: 1ffff92000613e74
fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212
inet_rtm_newroute+0x147/0x230 net/ipv4/fib_frontend.c:905
rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmsg net/socket.c:2528 [inline]
__do_sys_sendmsg net/socket.c:2537 [inline]
__se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f528ee22eb9
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:00007f528d07e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f528f09dfa0 RCX: 00007f528ee22eb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007f528ee90c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f528f09e038 R14: 00007f528f09dfa0 R15: 00007ffcaa9289d8
</TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g59225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=22026
rcu: rcu_preempt kthread starved for 10502 jiffies! g59225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27184 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15122 Comm: syz.4.3616 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0xe7/0x7d10 kernel/locking/lockdep.c:4882
Code: 2d 9e 67 a5 7e 48 c7 c0 44 0c 8a 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 cb 65 00 00 83 3d 03 04 2d 0c 00 0f 84 a8 27 00 00 <83> 3d 92 d4 c1 0a 00 74 29 48 89 d8 48 c1 e8 03 42 80 3c 00 00 74
RSP: 0018:ffffc90000006c80 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffffffff8c31eaa0 RCX: 1ffff92000000db4
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c31eaa0
RBP: ffffc90000006ed0 R08: dffffc0000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1b13b16 R12: 0000000000000000
R13: ffff88802282bb80 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f528d07e6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c342428 CR3: 00000000543a9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__perf_output_begin kernel/events/ring_buffer.c:163 [inline]
perf_output_begin_forward+0xa5/0xa40 kernel/events/ring_buffer.c:271
__perf_event_output kernel/events/core.c:7804 [inline]
perf_event_output_forward+0x19b/0x2e0 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 c2 ef 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 5039e980bf158900 RBX: 1ffff92000000ef8 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: ffffc90000007880 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffffff8c322f00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
netif_receive_skb_list_internal+0x961/0xbd0 net/core/dev.c:5760
gro_normal_list net/core/dev.c:5913 [inline]
napi_complete_done+0x378/0x850 net/core/dev.c:6651
virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline]
virtnet_poll+0x955/0xf40 drivers/net/virtio_net.c:1624
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4d4/0xa10 net/core/dev.c:7232
handle_softirqs+0x339/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
</IRQ>
<TASK>
asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 4c 80 67 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 b6 eb 70 08 e8 41 e0 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc9000309ed48 EFLAGS: 00000286
RAX: 5039e980bf158900 RBX: ffff8880b903a340 RCX: 5039e980bf158900
RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f780
RBP: 1ffff11017207613 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:fib_create_info+0x1221/0x24f0 net/ipv4/fib_semantics.c:1646
Code: 00 74 6d e8 a1 8d 00 f9 4c 8b 3c 24 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 28 92 45 f9 4d 89 37 41 be ea ff ff ff <48> 8d 7b 44 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 92 10 00
RSP: 0018:ffffc9000309f128 EFLAGS: 00000287
RAX: ffffffff88788faf RBX: ffff888141f96a00 RCX: 0000000000080000
RDX: ffffc9000ce81000 RSI: 000000000000cf38 RDI: 000000000000cf39
RBP: dffffc0000000000 R08: ffffffff901d10cf R09: 1ffffffff203a219
R10: dffffc0000000000 R11: fffffbfff203a21a R12: ffffc9000309f3a0
R13: ffffc9000309f3a4 R14: 00000000ffffffea R15: 1ffff92000613e74
fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212
inet_rtm_newroute+0x147/0x230 net/ipv4/fib_frontend.c:905
rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684
netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmsg net/socket.c:2528 [inline]
__do_sys_sendmsg net/socket.c:2537 [inline]
__se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f528ee22eb9
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:00007f528d07e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f528f09dfa0 RCX: 00007f528ee22eb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007f528ee90c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f528f09e038 R14: 00007f528f09dfa0 R15: 00007ffcaa9289d8
</TASK>
---
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