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INFO: rcu detected stall in dev_ioctl

Status: upstream: reported on 2026/04/05 17:14
Reported-by: syzbot+f01cb5bfb3ee48171ef1@syzkaller.appspotmail.com
First crash: 5d15h, last: 5d03h
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in dev_ioctl (2) 1 5 14d 118d 0/3 upstream: reported on 2025/12/13 22:16
linux-4.19 INFO: rcu detected stall in dev_ioctl 1 1 2047d 2047d 0/1 auto-closed as invalid on 2020/12/30 14:33
linux-4.19 INFO: rcu detected stall in dev_ioctl (2) 1 1 1685d 1685d 0/1 auto-closed as invalid on 2021/12/27 14:21
upstream INFO: rcu detected stall in dev_ioctl batman 1 18 1460d 2328d 0/29 auto-closed as invalid on 2022/08/09 13:29
linux-4.19 INFO: rcu detected stall in dev_ioctl (3) 1 1 1562d 1562d 0/1 auto-closed as invalid on 2022/04/29 15:27
linux-6.1 BUG: soft lockup in dev_ioctl 1 6 106d 264d 0/3 auto-obsoleted due to no activity on 2026/04/05 06:22
linux-5.15 INFO: rcu detected stall in dev_ioctl 1 1 495d 495d 0/3 auto-obsoleted due to no activity on 2025/03/11 17:46
linux-6.6 INFO: rcu detected stall in dev_ioctl 1 1 229d 229d 0/2 auto-obsoleted due to no activity on 2025/12/02 20:33
upstream INFO: rcu detected stall in dev_ioctl (2) mm 1 3 460d 544d 0/29 auto-obsoleted due to no activity on 2025/04/05 21:09
upstream BUG: soft lockup in dev_ioctl (2) mm 1 6 162d 231d 0/29 auto-obsoleted due to no activity on 2026/02/07 12:10
upstream BUG: soft lockup in dev_ioctl batman 1 2 696d 761d 0/29 auto-obsoleted due to no activity on 2024/08/13 06:45
android-5-15 BUG: soft lockup in dev_ioctl 1 7 623d 713d 0/2 auto-obsoleted due to no activity on 2024/10/24 08:58

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2641 jiffies s: 90821 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: 15071 Comm: syz.5.2799 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__perf_event_output kernel/events/core.c:7723 [inline]
RIP: 0010:perf_event_output_forward+0x9e/0x2f0 kernel/events/core.c:7750
Code: 4a 89 04 33 48 b8 f8 f8 f8 f2 f2 f2 f2 f2 4a 89 44 33 08 42 c7 44 33 10 f8 f3 f3 f3 e8 1b 5a dd ff 42 c7 44 33 04 00 00 00 00 <66> 42 c7 44 33 08 00 00 42 c6 44 33 0a 00 42 c6 44 33 10 00 e8 49
RSP: 0018:ffffc900001e0020 EFLAGS: 00000046
RAX: ffffffff81a51a75 RBX: 1ffff9200003c008 RCX: ffff88802ddc1dc0
RDX: 0000000000000100 RSI: ffffc900001e0300 RDI: ffff88803a629800
RBP: ffffc900001e0128 R08: ffff88803a629c7b R09: 1ffff110074c538f
R10: dffffc0000000000 R11: ffffed10074c5390 R12: ffffc900001e0300
R13: ffffc900001e00c0 R14: dffffc0000000000 R15: ffff88803a629800
FS:  00007f734526b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb25ab456b8 CR3: 000000004bdf5000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000008d24
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __perf_event_overflow+0x448/0x610 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+0x3e7/0xc30 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 d2 33 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:ffffc900001e0740 EFLAGS: 00000206
RAX: ee403d39c8be4200 RBX: 1ffff9200003c0f0 RCX: ee403d39c8be4200
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20
RBP: ffffc900001e0840 R08: ffffffff90af7267 R09: 1ffffffff215ee4c
R10: dffffc0000000000 R11: fffffbfff215ee4d R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 netif_receive_skb_list_internal+0xa11/0xca0 net/core/dev.c:5842
 gro_normal_list include/net/gro.h:433 [inline]
 napi_complete_done+0x378/0x850 net/core/dev.c:6182
 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline]
 virtnet_poll+0x9b7/0x1180 drivers/net/virtio_net.c:1717
 __napi_poll+0xc0/0x460 net/core/dev.c:6616
 napi_poll net/core/dev.c:6683 [inline]
 net_rx_action+0x5dd/0xb20 net/core/dev.c:6797
 handle_softirqs+0x2a1/0x930 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
 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
 </IRQ>
 <TASK>
 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5124
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 00 2c de 08 e8 8b 2c 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90004a67278 EFLAGS: 00000286
RAX: ee403d39c8be4200 RBX: 0000000000000000 RCX: ee403d39c8be4200
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20
RBP: ffffc90004a672d0 R08: ffffffff90af7267 R09: 1ffffffff215ee4c
R10: dffffc0000000000 R11: fffffbfff215ee4d R12: ffff88802ddc1dc0
R13: dffffc0000000000 R14: ffff88802bf19dc0 R15: ffff8880b8f3b5d0
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x11d9/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 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:arch_atomic_set arch/x86/include/asm/atomic.h:41 [inline]
RIP: 0010:atomic_set include/linux/atomic/atomic-instrumented.h:42 [inline]
RIP: 0010:refcount_set include/linux/refcount.h:136 [inline]
RIP: 0010:__build_skb_around net/core/skbuff.c:283 [inline]
RIP: 0010:__alloc_skb+0x30e/0x7e0 net/core/skbuff.c:530
Code: 00 41 89 ae e0 00 00 00 4d 8d be e4 00 00 00 4c 89 ff be 04 00 00 00 e8 60 c1 a8 f9 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 <4c> 89 ed 0f 85 dc 02 00 00 41 c7 86 e4 00 00 00 01 00 00 00 4d 8d
RSP: 0018:ffffc90004a675e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888057022400 RCX: ffffffff882abff0
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88802e196c24
RBP: 0000000000000300 R08: ffff88802e196c27 R09: 1ffff11005c32d84
R10: dffffc0000000000 R11: ffffed1005c32d85 R12: 0000000000000200
R13: dffffc0000000000 R14: ffff88802e196b40 R15: ffff88802e196c24
 alloc_skb include/linux/skbuff.h:1303 [inline]
 alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:290
 uevent_net_broadcast_tagged lib/kobject_uevent.c:351 [inline]
 kobject_uevent_net_broadcast+0x17e/0x530 lib/kobject_uevent.c:412
 kobject_uevent_env+0x54c/0x8a0 lib/kobject_uevent.c:608
 rx_queue_add_kobject net/core/net-sysfs.c:1072 [inline]
 net_rx_queue_update_kobjects+0x23f/0x4a0 net/core/net-sysfs.c:1112
 register_queue_kobjects net/core/net-sysfs.c:1772 [inline]
 netdev_register_kobject+0x231/0x320 net/core/net-sysfs.c:2017
 register_netdevice+0x12dc/0x1b00 net/core/dev.c:10230
 ip6_tnl_create2+0x80/0x140 net/ipv6/ip6_tunnel.c:261
 ip6_tnl_create net/ipv6/ip6_tunnel.c:311 [inline]
 ip6_tnl_locate+0x731/0x830 net/ipv6/ip6_tunnel.c:361
 ip6_tnl_siocdevprivate+0x5ef/0xaf0 net/ipv6/ip6_tunnel.c:1672
 dev_siocdevprivate net/core/dev_ioctl.c:287 [inline]
 dev_ifsioc+0xa4a/0xd40 net/core/dev_ioctl.c:392
 dev_ioctl+0x5f8/0xe80 net/core/dev_ioctl.c:597
 sock_ioctl+0x691/0x710 net/socket.c:1245
 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: 0033:0x7f734439c819
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:00007f734526b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7344615fa0 RCX: 00007f734439c819
RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 0000000000000012
RBP: 00007f7344432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7344616038 R14: 00007f7344615fa0 R15: 00007ffedd5ce468
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/06 04:42 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in dev_ioctl
2026/04/05 17:13 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in dev_ioctl
* Struck through repros no longer work on HEAD.