syzbot


INFO: rcu detected stall in inet_rtm_newroute

Status: upstream: reported on 2026/06/19 07:06
Reported-by: syzbot+4859c72e0e30394d6303@syzkaller.appspotmail.com
First crash: 11d, last: 11d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in inet_rtm_newroute net 1 1 165d 165d 0/29 auto-obsoleted due to no activity on 2026/04/16 16:13
linux-5.15 INFO: rcu detected stall in inet_rtm_newroute 1 1 150d 150d 0/3 auto-obsoleted due to no activity on 2026/05/11 20:30

Sample crash report:
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10488 ticks this GP) idle=5f24/1/0x4000000000000000 softirq=21697/21699 fqs=350
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  2179638       2555            0
rcu: 	cputime:    33141      19272           60   ==> 52470(ms)
rcu: 	(t=10500 jiffies g=24433 q=853 ncpus=2)
rcu: rcu_preempt kthread starved for 717 jiffies! g24433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26992 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 8450 Comm: syz.3.759 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x80 kernel/kcov.c:293
Code: 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 90 88 7c 7e 65 8b 15 91 88 7c 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900000064b0 EFLAGS: 00000202
RAX: ffffffff813b3949 RBX: ffffffff816b9bb8 RCX: ffff8880218a5a00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffffffff816b9bb8
RBP: ffffc900000065d8 R08: ffffc90000006650 R09: 0000000000000023
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000006588
R13: dffffc0000000000 R14: ffffc900000065bd R15: 0000000000000001
FS:  00007f4a9347d6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd7ee17dac CR3: 000000007a264000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 orc_find arch/x86/kernel/unwind_orc.c:202 [inline]
 unwind_next_frame+0x189/0x2970 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x270 mm/slub.c:3852
 skb_ext_del include/linux/skbuff.h:4830 [inline]
 nf_bridge_info_free net/bridge/br_netfilter_hooks.c:152 [inline]
 br_nf_dev_queue_xmit+0x492/0x1b80 net/bridge/br_netfilter_hooks.c:-1
 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304
 br_nf_post_routing+0xb41/0xfb0 net/bridge/br_netfilter_hooks.c:977
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302
 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1184 [inline]
 br_nf_forward_finish+0xa51/0xe80 net/bridge/br_netfilter_hooks.c:684
 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304
 br_nf_forward_ip+0xcc1/0x1110 net/bridge/br_netfilter_hooks.c:754
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302
 __br_forward+0x433/0x610 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x13c5/0x18f0 net/bridge/br_input.c:215
 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184
 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:304 [inline]
 br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
 br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5540
 __netif_receive_skb_one_core net/core/dev.c:5644 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5760
 process_backlog+0x391/0x6f0 net/core/dev.c:6088
 __napi_poll+0xc0/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x616/0xc40 net/core/dev.c:6853
 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+0xd3/0x190 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:info_print_prefix+0x18f/0x360 kernel/printk/printk.c:1355
Code: cb 8a e8 a4 1a 0d 09 48 98 48 01 c3 4c 8d 6c 24 40 49 83 c6 14 4c 89 f0 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 0f b6 04 10 <84> c0 0f 85 00 01 00 00 45 8b 26 4c 8b 7c 24 10 4d 8d 34 1f 48 89
RSP: 0018:ffffc900044de600 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: 000000000000000e RCX: e1751909d8434d00
RDX: dffffc0000000000 RSI: 000000000002c4f5 RDI: 000000000002c4f6
RBP: ffffc900044de6b0 R08: ffffc900044de74d R09: 1ffff9200089bce9
R10: dffffc0000000000 R11: fffff5200089bcea R12: 0000000000000000
R13: ffffc900044de640 R14: ffffc900044de8d4 R15: ffffc900044de8c8
 record_print_text+0x177/0x450 kernel/printk/printk.c:1402
 printk_get_next_message+0x2ab/0x980 kernel/printk/printk.c:2876
 console_emit_next_record kernel/printk/printk.c:2911 [inline]
 console_flush_all+0x3a8/0xd20 kernel/printk/printk.c:3000
 console_unlock+0xad/0x350 kernel/printk/printk.c:3069
 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
 _printk+0xde/0x130 kernel/printk/printk.c:2366
 validate_nla lib/nlattr.c:414 [inline]
 __nla_validate_parse+0x17fa/0x2ea0 lib/nlattr.c:635
 __nla_validate+0x40/0x50 lib/nlattr.c:677
 nlmsg_validate_deprecated include/net/netlink.h:898 [inline]
 rtm_to_fib_config+0x91/0x13b0 net/ipv4/fib_frontend.c:736
 inet_rtm_newroute+0x116/0x240 net/ipv4/fib_frontend.c:907
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4a9259ce59
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:00007f4a9347d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4a92815fa0 RCX: 00007f4a9259ce59
RDX: 000000002002c040 RSI: 00002000000003c0 RDI: 0000000000000007
RBP: 00007f4a92632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a92816038 R14: 00007f4a92815fa0 R15: 00007ffcf5c61ad8
 </TASK>
CPU: 0 PID: 8450 Comm: syz.3.759 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x80 kernel/kcov.c:293
Code: 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 90 88 7c 7e 65 8b 15 91 88 7c 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900000064b0 EFLAGS: 00000202
RAX: ffffffff813b3949 RBX: ffffffff816b9bb8 RCX: ffff8880218a5a00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffffffff816b9bb8
RBP: ffffc900000065d8 R08: ffffc90000006650 R09: 0000000000000023
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000006588
R13: dffffc0000000000 R14: ffffc900000065bd R15: 0000000000000001
FS:  00007f4a9347d6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd7ee17dac CR3: 000000007a264000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 orc_find arch/x86/kernel/unwind_orc.c:202 [inline]
 unwind_next_frame+0x189/0x2970 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x270 mm/slub.c:3852
 skb_ext_del include/linux/skbuff.h:4830 [inline]
 nf_bridge_info_free net/bridge/br_netfilter_hooks.c:152 [inline]
 br_nf_dev_queue_xmit+0x492/0x1b80 net/bridge/br_netfilter_hooks.c:-1
 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304
 br_nf_post_routing+0xb41/0xfb0 net/bridge/br_netfilter_hooks.c:977
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302
 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1184 [inline]
 br_nf_forward_finish+0xa51/0xe80 net/bridge/br_netfilter_hooks.c:684
 NF_HOOK+0x66e/0x700 include/linux/netfilter.h:304
 br_nf_forward_ip+0xcc1/0x1110 net/bridge/br_netfilter_hooks.c:754
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302
 __br_forward+0x433/0x610 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x13c5/0x18f0 net/bridge/br_input.c:215
 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184
 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:304 [inline]
 br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
 br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5540
 __netif_receive_skb_one_core net/core/dev.c:5644 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5760
 process_backlog+0x391/0x6f0 net/core/dev.c:6088
 __napi_poll+0xc0/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x616/0xc40 net/core/dev.c:6853
 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+0xd3/0x190 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:info_print_prefix+0x18f/0x360 kernel/printk/printk.c:1355
Code: cb 8a e8 a4 1a 0d 09 48 98 48 01 c3 4c 8d 6c 24 40 49 83 c6 14 4c 89 f0 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 0f b6 04 10 <84> c0 0f 85 00 01 00 00 45 8b 26 4c 8b 7c 24 10 4d 8d 34 1f 48 89
RSP: 0018:ffffc900044de600 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: 000000000000000e RCX: e1751909d8434d00
RDX: dffffc0000000000 RSI: 000000000002c4f5 RDI: 000000000002c4f6
RBP: ffffc900044de6b0 R08: ffffc900044de74d R09: 1ffff9200089bce9
R10: dffffc0000000000 R11: fffff5200089bcea R12: 0000000000000000
R13: ffffc900044de640 R14: ffffc900044de8d4 R15: ffffc900044de8c8
 record_print_text+0x177/0x450 kernel/printk/printk.c:1402
 printk_get_next_message+0x2ab/0x980 kernel/printk/printk.c:2876
 console_emit_next_record kernel/printk/printk.c:2911 [inline]
 console_flush_all+0x3a8/0xd20 kernel/printk/printk.c:3000
 console_unlock+0xad/0x350 kernel/printk/printk.c:3069
 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
 _printk+0xde/0x130 kernel/printk/printk.c:2366
 validate_nla lib/nlattr.c:414 [inline]
 __nla_validate_parse+0x17fa/0x2ea0 lib/nlattr.c:635
 __nla_validate+0x40/0x50 lib/nlattr.c:677
 nlmsg_validate_deprecated include/net/netlink.h:898 [inline]
 rtm_to_fib_config+0x91/0x13b0 net/ipv4/fib_frontend.c:736
 inet_rtm_newroute+0x116/0x240 net/ipv4/fib_frontend.c:907
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4a9259ce59
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:00007f4a9347d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4a92815fa0 RCX: 00007f4a9259ce59
RDX: 000000002002c040 RSI: 00002000000003c0 RDI: 0000000000000007
RBP: 00007f4a92632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a92816038 R14: 00007f4a92815fa0 R15: 00007ffcf5c61ad8
 </TASK>
net_ratelimit: 7151 callbacks suppressed
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
NMI backtrace for cpu 0
CPU: 0 PID: 8450 Comm: syz.3.759 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x4aa/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 29 e0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d 8d 3c 44 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 75 3e 4d 63 2f <4d> 01 fd 4c 89 ef 4c 89 f6 e8 28 f1 4b 00 49 8d 47 04 4d 39 f5 4c
RSP: 0018:ffffc90000006a98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8ef6f248 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 000000000017c419 RDI: 000000000017c41a
RBP: ffffffff8ef6f248 R08: ffffc90000006c30 R09: 0000000000000009
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8ef6f248
R13: fffffffffa6aa100 R14: ffffffff8961a304 R15: ffffffff8ef6f248
FS:  00007f4a9347d6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcd7ee17dac CR3: 000000007a264000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519
 skb_ext_maybe_cow net/core/skbuff.c:6670 [inline]
 skb_ext_add+0x1b3/0x8e0 net/core/skbuff.c:6744
 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline]
 br_nf_forward_ip+0xc6/0x1110 net/bridge/br_netfilter_hooks.c:709
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:259 [inline]
 NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302
 __br_forward+0x433/0x610 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x13c5/0x18f0 net/bridge/br_input.c:215
 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184
 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:304 [inline]
 br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
 br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5540
 __netif_receive_skb_one_core net/core/dev.c:5644 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5760
 process_backlog+0x391/0x6f0 net/core/dev.c:6088
 __napi_poll+0xc0/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x616/0xc40 net/core/dev.c:6853
 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+0xd3/0x190 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:vsnprintf+0x14d5/0x1ba0 lib/vsprintf.c:2773
Code: 41 8b 17 49 bf 00 00 00 00 00 fc ff df 4c 89 ef 4c 89 e6 48 89 d9 e8 ea 2e 00 00 49 89 c5 48 89 e8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 77 80 7d 00 00 0f 84 a8 05 00 00 e8 b8 54 0e f7 49 89 ef
RSP: 0018:ffffc900044de478 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000005b
RDX: 0000000000000000 RSI: ffffffff8acb8d40 RDI: ffffc900044de740
RBP: ffffffff8acb8d41 R08: ffffc900044de740 R09: 1ffff9200089bce8
R10: dffffc0000000000 R11: fffff5200089bce9 R12: ffffc900844de73f
R13: ffffc900044de741 R14: 0000000000000001 R15: dffffc0000000000
 sprintf+0xe8/0x140 lib/vsprintf.c:3027
 print_time kernel/printk/printk.c:1327 [inline]
 info_print_prefix+0x16c/0x360 kernel/printk/printk.c:1353
 record_print_text+0x177/0x450 kernel/printk/printk.c:1402
 printk_get_next_message+0x2ab/0x980 kernel/printk/printk.c:2876
 console_emit_next_record kernel/printk/printk.c:2911 [inline]
 console_flush_all+0x3a8/0xd20 kernel/printk/printk.c:3000
 console_unlock+0xad/0x350 kernel/printk/printk.c:3069
 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
 _printk+0xde/0x130 kernel/printk/printk.c:2366
 validate_nla lib/nlattr.c:414 [inline]
 __nla_validate_parse+0x17fa/0x2ea0 lib/nlattr.c:635
 __nla_validate+0x40/0x50 lib/nlattr.c:677
 nlmsg_validate_deprecated include/net/netlink.h:898 [inline]
 rtm_to_fib_config+0x91/0x13b0 net/ipv4/fib_frontend.c:736
 inet_rtm_newroute+0x116/0x240 net/ipv4/fib_frontend.c:907
 rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6476
 netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5ba/0x960 net/socket.c:2594
 ___sys_sendmsg+0x2a6/0x360 net/socket.c:2648
 __sys_sendmsg net/socket.c:2677 [inline]
 __do_sys_sendmsg net/socket.c:2686 [inline]
 __se_sys_sendmsg+0x1c2/0x2b0 net/socket.c:2684
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4a9259ce59
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:00007f4a9347d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4a92815fa0 RCX: 00007f4a9259ce59
RDX: 000000002002c040 RSI: 00002000000003c0 RDI: 0000000000000007
RBP: 00007f4a92632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a92816038 R14: 00007f4a92815fa0 R15: 00007ffcf5c61ad8
 </TASK>
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)
bridge0: received packet on bond0 with own address as source address (addr:8a:91:ec:11:b6:91, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/19 07:05 linux-6.6.y 924b4a879cbb a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in inet_rtm_newroute
* Struck through repros no longer work on HEAD.