syzbot

 sign-in | mailing list | source | docs
🐞 Open [854]
🐞 Fixed [87]
🐞 Invalid [1300]
⬇ Missing Backports [132]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in rtnl_dellink

Status: auto-obsoleted due to no activity on 2026/01/01 07:23
Reported-by: syzbot+37f96260bdf376da1b6a@syzkaller.appspotmail.com
First crash: 304d, last: 224d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in rtnl_dellink 1 1 436d 436d 0/3 auto-obsoleted due to no activity on 2025/06/03 01:04
linux-6.6 INFO: rcu detected stall in rtnl_dellink 1 1 100d 100d 0/2 auto-obsoleted due to no activity on 2026/05/05 01:43
linux-6.1 INFO: rcu detected stall in rtnl_dellink (2) 1 3 16d 89d 0/3 upstream: reported on 2026/02/05 02:24
linux-5.15 INFO: rcu detected stall in rtnl_dellink (2) 1 2 78d 85d 0/3 upstream: reported on 2026/02/09 08:45
upstream INFO: rcu detected stall in rtnl_dellink net 1 2 437d 504d 0/29 auto-obsoleted due to no activity on 2025/05/23 22:00

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=7a5/1/0x4000000000000000 softirq=23642/23643 fqs=5246 
	(detected by 1, t=10502 jiffies, g=32881, q=747)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9157 Comm: syz.0.1221 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__lock_acquire+0x1279/0x7c60 kernel/locking/lockdep.c:5008
Code: 49 b8 00 00 00 00 00 fc ff df 42 0f b6 04 00 84 c0 0f 85 f2 5b 00 00 83 3d b3 1f b0 14 00 0f 84 26 08 00 00 31 db 48 83 c3 40 <48> 89 d8 48 c1 e8 03 42 80 3c 00 00 74 12 48 89 df e8 41 23 60 00
RSP: 0018:ffffc90000006f80 EFLAGS: 00000082
RAX: 0000000000000fc0 RBX: ffffffff8f944f80 RCX: ffffffff815c0e0f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbc0c0
RBP: ffffc900000071d0 R08: dffffc0000000000 R09: fffffbfff1ff7819
R10: fffffbfff1ff7819 R11: 1ffffffff1ff7818 R12: 00000000e3db5d87
R13: ffff88807a1bd940 R14: 0000000038c72385 R15: ffff88807a1be4c8
FS:  00007fe008bc36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32963fff CR3: 000000005864f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 __perf_output_begin kernel/events/ring_buffer.c:163 [inline]
 perf_output_begin_forward+0x97/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7804 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 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+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: b0dca55538330700 RBX: 1ffff92000000f60 RCX: b0dca55538330700
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff781a
R10: fffffbfff1ff781a R11: 1ffffffff1ff7819 R12: ffffffff8c120b00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1771
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x132/0x1b0 kernel/softirq.c:408
Code: 8a e8 52 8c 60 08 65 66 8b 05 ca 25 bb 7e 66 85 c0 75 54 bf 01 00 00 00 e8 9b fe 08 00 e8 06 76 35 00 fb 65 8b 05 76 fc b9 7e <85> c0 75 05 e8 25 07 b8 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc9000321e960 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 0000000000000201 RCX: b0dca55538330700
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc9000321e9f0 R08: dffffc0000000000 R09: fffffbfff1ff781a
R10: fffffbfff1ff781a R11: 1ffffffff1ff7819 R12: ffffffff888d0caf
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff92000643d2c
 spin_unlock_bh include/linux/spinlock.h:408 [inline]
 addrconf_ifdown+0x60f/0x1970 net/ipv6/addrconf.c:3829
 addrconf_notify+0x445/0xf00 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 dev_close_many+0x28d/0x400 net/core/dev.c:1650
 vlan_device_event+0x1244/0x1fa0 net/8021q/vlan.c:475
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 dev_close_many+0x28d/0x400 net/core/dev.c:1650
 unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110
 rtnl_delete_link net/core/rtnetlink.c:3112 [inline]
 rtnl_dellink+0x3db/0x700 net/core/rtnetlink.c:3163
 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 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+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x190/0x250 net/socket.c:2526
 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: 0033:0x7fe00a95bec9
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:00007fe008bc3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe00abb2fa0 RCX: 00007fe00a95bec9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000008
RBP: 00007fe00a9def91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe00abb3038 R14: 00007fe00abb2fa0 R15: 00007ffc5b43ec08
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/23 07:23 linux-5.15.y 43bb85222e53 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in rtnl_dellink
2025/09/05 08:57 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in rtnl_dellink
2025/07/05 13:57 linux-5.15.y 3dea0e7f549e 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in rtnl_dellink
* Struck through repros no longer work on HEAD.