INFO: rcu detected stall in rtnl_newlink (5)

Status: upstream: reported C repro on 2026/08/02 19:23
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+f2689b711221203605d4@syzkaller.appspotmail.com
First crash: 53d, last: 10d
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2026/09/06 upstream (ToT) 1fc5a74b108f C [report] INFO: rcu detected stall in schedule_timeout
▶ ▼ Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in rtnl_newlink (5) prio:normal net 1 syz, C error 252 3h05m 529d 0/29 upstream: reported C repro on 2025/04/14 04:26
linux-6.1 INFO: rcu detected stall in rtnl_newlink (2) 1 3 834d 926d 0/3 auto-obsoleted due to no activity on 2024/09/20 22:26
upstream INFO: rcu detected stall in rtnl_newlink batman 1 syz, C done inconclusive 201 1451d 2254d 0/29 auto-obsoleted due to no activity on 2023/02/01 16:38
linux-6.6 INFO: rcu detected stall in rtnl_newlink origin:upstream 1 syz, C error 5 2d05h 462d 0/2 upstream: reported C repro on 2025/06/20 10:45
upstream INFO: rcu detected stall in rtnl_newlink (4) sctp fs 1 syz, C error 9 862d 938d 25/29 fixed on 2024/05/22 23:36
linux-6.1 INFO: rcu detected stall in rtnl_newlink (4) 1 1 332d 332d 0/3 auto-obsoleted due to no activity on 2026/02/05 08:34
upstream INFO: rcu detected stall in rtnl_newlink (3) batman 1 syz, C error done 3 1126d 1176d 0/29 auto-obsoleted due to no activity on 2023/12/03 18:15
linux-6.1 INFO: rcu detected stall in rtnl_newlink 1 1 1081d 1081d 0/3 auto-obsoleted due to no activity on 2024/01/17 21:04
linux-5.15 BUG: soft lockup in rtnl_newlink origin:lts-only 1 syz, C inconclusive 65 803d 1295d 0/3 auto-obsoleted due to no activity on 2024/10/21 17:39
linux-5.15 INFO: rcu detected stall in rtnl_newlink origin:upstream 1 syz error 13 7d08h 691d 0/3 upstream: reported syz repro on 2024/11/02 18:01
linux-4.19 INFO: rcu detected stall in rtnl_newlink 1 syz, C error 7 1381d 2254d 0/1 upstream: reported C repro on 2020/07/24 01:06
linux-6.1 INFO: rcu detected stall in rtnl_newlink (3) 1 2 486d 498d 0/3 auto-obsoleted due to no activity on 2025/09/03 19:02
upstream INFO: rcu detected stall in rtnl_newlink (2) net 1 1 1320d 1320d 0/29 auto-obsoleted due to no activity on 2023/05/13 18:46
android-5-15 BUG: soft lockup in rtnl_newlink 1 7 780d 890d 0/2 auto-obsoleted due to no activity on 2024/11/04 06:23
android-6-1 BUG: soft lockup in rtnl_newlink 1 2 794d 804d 0/2 auto-obsoleted due to no activity on 2024/10/20 23:12
linux-4.14 BUG: soft lockup in rtnl_newlink 1 1 1703d 1703d 0/1 auto-closed as invalid on 2022/05/26 06:33
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/09/14 18:10 2h55m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4388/1:b..l
	(detected by 1, t=10503 jiffies, g=10565, q=1113 ncpus=2)
task:syz-executor    state:R  running task     stack:21616 pid:4388  ppid:4385   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:ether_addr_equal include/linux/etherdevice.h:349 [inline]
RIP: 0010:ether_addr_equal_unaligned include/linux/etherdevice.h:402 [inline]
RIP: 0010:batadv_compare_eth net/batman-adv/main.h:267 [inline]
RIP: 0010:batadv_check_known_mac_addr+0x1c0/0x3e0 net/batman-adv/hard-interface.c:521
Code: 8b 44 24 20 42 80 3c 28 00 74 08 4c 89 f7 e8 6f 40 db f7 49 8b 2e 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 fa 00 00 00 <44> 8b 33 48 89 e8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 00 01 00
RSP: 0018:ffffc90003ea6e18 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888027a1b928 RCX: 0000000000000000
RDX: ffff888029df0000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff88805712cc28 R08: ffffc90003ea6aa7 R09: 1ffff920007d4d54
R10: dffffc0000000000 R11: fffff520007d4d55 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88807c328380 R15: ffff88802973d800
 batadv_hard_if_event+0x490/0x1510 net/batman-adv/hard-interface.c:992
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 dev_set_mac_address+0x2ed/0x400 net/core/dev.c:8937
 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:8951
 do_setlink+0x7eb/0x29c0 net/core/rtnetlink.c:2800
 __rtnl_newlink net/core/rtnetlink.c:3622 [inline]
 rtnl_newlink+0x16e4/0x1f90 net/core/rtnetlink.c:3669
 rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166
 netlink_rcv_skb+0x1ef/0x440 net/netlink/af_netlink.c:2516
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x497/0x650 net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2161
 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: 0033:0x7f03f3b5e84e
RSP: 002b:00007ffcb4a0f608 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555578480500 RCX: 00007f03f3b5e84e
RDX: 000000000000002c RSI: 00007f03f4954670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffcb4a0f684 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f03f4954670 R15: 0000000000000000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/02 19:23 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in rtnl_newlink
2026/08/12 06:28 linux-6.1.y e4f7d8be268e f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in rtnl_newlink
* Struck through repros no longer work on HEAD.