INFO: rcu detected stall in inet_ioctl

Status: upstream: reported on 2026/05/26 00:31
Reported-by: syzbot+24f81a96894a6c85df30@syzkaller.appspotmail.com
First crash: 84d, last: 2h18m
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in inet_ioctl (3) prio:low mm 1 1 164d 164d 0/29 auto-obsoleted due to no activity on 2026/06/05 17:53
upstream INFO: rcu detected stall in inet_ioctl net 1 1 2636d 2636d 0/29 auto-closed as invalid on 2019/10/25 09:21
upstream INFO: rcu detected stall in inet_ioctl (2) mm 1 1 691d 690d 0/29 auto-obsoleted due to no activity on 2024/12/25 20:16
linux-6.6 INFO: rcu detected stall in inet_ioctl 1 1 53d 53d 0/2 upstream: reported on 2026/06/26 19:25

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2663 jiffies s: 4569 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5090 Comm: syz.4.206 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x80 kernel/kcov.c:321
Code: 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 90 <48> 8b 04 24 65 48 8b 0d 34 3d 80 7e 65 8b 15 35 3d 80 7e 81 e2 00
RSP: 0018:ffffc900001e0158 EFLAGS: 00000046
RAX: 1ffff9200003c0be RBX: ffffc900001e05f0 RCX: ffff88802e4b5a00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001e0250 R08: ffff88802e4b5a07 R09: 1ffff11005c96b40
R10: dffffc0000000000 R11: ffffed1005c96b41 R12: 1ffff9200003c0bc
R13: ffff88801de58000 R14: 00000000000f250c R15: dffffc0000000000
FS:  00007fef3614d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f44bf027dac CR3: 00000000792ed000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 perf_prepare_sample+0x13c3/0x2020 kernel/events/core.c:7664
 __perf_event_output kernel/events/core.c:7730 [inline]
 perf_event_output_forward+0x197/0x2f0 kernel/events/core.c:7750
 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9496
 perf_swevent_overflow kernel/events/core.c:9579 [inline]
 perf_swevent_event+0x315/0x570 kernel/events/core.c:9630
 perf_tp_event+0x36b/0xc10 kernel/events/core.c:10064
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
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 a2 7c 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e0980 EFLAGS: 00000206
RAX: 1a507ea6a9a66a00 RBX: 1ffff9200003c138 RCX: 1a507ea6a9a66a00
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffffc900001e0a80 R08: ffffffff90b1032f R09: 1ffffffff2162065
R10: dffffc0000000000 R11: fffffbfff2162066 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 hsr_announce+0x2ca/0x340 net/hsr/hsr_device.c:407
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:kasan_quarantine_put+0x84/0x210 mm/kasan/quarantine.c:245
Code: e8 f1 2f b5 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 00 67 03 00 45
RSP: 0018:ffffc9001c6e7380 EFLAGS: 00000206
RAX: 1a507ea6a9a66a01 RBX: ffff888026251500 RCX: 1a507ea6a9a66a00
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffff888026251500 R08: ffffffff90b1027f R09: 1ffffffff216204f
R10: dffffc0000000000 R11: fffffbfff2162050 R12: 0000000000000000
R13: ffffc9001c6e7418 R14: 00000000000af5e0 R15: 0000000000000286
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709
 netlink_broadcast+0xffd/0x10f0 net/netlink/af_netlink.c:1526
 nlmsg_multicast include/net/netlink.h:1078 [inline]
 nlmsg_notify+0xe3/0x1a0 net/netlink/af_netlink.c:2559
 fib_table_delete+0xcce/0xfc0 net/ipv4/fib_trie.c:1746
 fib_magic+0x2ea/0x3b0 net/ipv4/fib_frontend.c:1120
 fib_del_ifaddr+0x1014/0x14c0 net/ipv4/fib_frontend.c:1322
 fib_inetaddr_event+0xb7/0x1c0 net/ipv4/fib_frontend.c:1462
 notifier_call_chain kernel/notifier.c:87 [inline]
 blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:382
 __inet_del_ifa+0xaac/0x1090 net/ipv4/devinet.c:445
 inet_del_ifa net/ipv4/devinet.c:482 [inline]
 devinet_ioctl+0x954/0x1bf0 net/ipv4/devinet.c:1180
 inet_ioctl+0x2fa/0x460 net/ipv4/af_inet.c:1008
 sock_do_ioctl+0xfb/0x320 net/socket.c:1202
 sock_ioctl+0x48a/0x700 net/socket.c:1321
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 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: 0033:0x7fef3519e0d9
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:00007fef3614d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fef35425fa0 RCX: 00007fef3519e0d9
RDX: 0000200000000040 RSI: 0000000000008916 RDI: 0000000000000007
RBP: 00007fef35235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fef35426038 R14: 00007fef35425fa0 R15: 00007fff24a5b478
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/18 20:23 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in inet_ioctl
2026/08/02 11:00 linux-6.1.y fb28aa725e05 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in inet_ioctl
2026/07/27 13:00 linux-6.1.y dc5c83b7f5f8 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in inet_ioctl
2026/05/26 00:30 linux-6.1.y dcbcab9d7079 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in inet_ioctl
* Struck through repros no longer work on HEAD.