syzbot


INFO: rcu detected stall in dev_ioctl (2)

Status: upstream: reported on 2025/12/13 22:16
Reported-by: syzbot+500341fa036814fb4ce0@syzkaller.appspotmail.com
First crash: 44d, last: 24d
Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in dev_ioctl 1 1 1973d 1973d 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 1611d 1611d 0/1 auto-closed as invalid on 2021/12/27 14:21
upstream INFO: rcu detected stall in dev_ioctl batman 1 18 1386d 2254d 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 1488d 1488d 0/1 auto-closed as invalid on 2022/04/29 15:27
linux-6.1 BUG: soft lockup in dev_ioctl 1 6 31d 190d 0/3 upstream: reported on 2025/07/20 19:44
linux-5.15 INFO: rcu detected stall in dev_ioctl 1 1 421d 421d 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 155d 155d 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 386d 470d 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 88d 157d 0/29 upstream: reported on 2025/08/22 13:27
upstream BUG: soft lockup in dev_ioctl batman 1 2 621d 686d 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 549d 639d 0/2 auto-obsoleted due to no activity on 2024/10/24 08:58

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (27 ticks this GP) idle=425/1/0x4000000000000002 softirq=7315/7315 fqs=2096 
	(detected by 1, t=10503 jiffies, g=7625, q=1557)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4638 Comm: syz.1.91 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x5/0x110 lib/smp_processor_id.c:13
Code: 60 dc 12 8a e8 2c 01 00 00 65 ff 0d 21 5d 61 76 5b c3 00 00 cc 48 c7 c7 a0 e7 59 8a 48 c7 c6 e0 e7 59 8a eb 00 55 41 57 41 56 <53> 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05
RSP: 0018:ffffc900000079c8 EFLAGS: 00000003
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff812a5080
RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8a59e7a0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f1014a486c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000001 CR3: 00000000238aa000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
 rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123
 trace_irq_work_exit arch/x86/include/asm/trace/irq_vectors.h:64 [inline]
 __sysvec_irq_work+0xcf/0x240 arch/x86/kernel/irq_work.c:23
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x4a/0xc0 arch/x86/kernel/irq_work.c:17
 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 ed 11 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: 0e6722bf07f54d00 RBX: 1ffff92000000f60 RCX: 0e6722bf07f54d00
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff541a
R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [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:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 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:preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6799
Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 70 bf 01 00 00 00 e8 af 44 a7 f7 e8 fa bd d3 f7 fb bf 01 00 00 00 <e8> ef b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc9000323f580 EFLAGS: 00000282
RAX: 0e6722bf07f54d00 RBX: 0000000000000000 RCX: 0e6722bf07f54d00
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: 0000000000000001
RBP: ffffc9000323f620 R08: dffffc0000000000 R09: fffffbfff1ff541a
R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000647eb0
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rtnl_fill_ifinfo+0x275/0x19e0 net/core/rtnetlink.c:1752
Code: 09 00 00 66 45 89 27 48 8b 5c 24 28 4c 8d bb d0 00 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 84 09 00 00 45 8b 3f <49> 8d 7e 14 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 87 09
RSP: 0018:ffffc9000323f6e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88805eac0000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807d214010
RBP: ffffc9000323f8f8 R08: 0000000000000010 R09: ffff88807d214020
R10: fffffbfff1a464e5 R11: 1ffffffff1a464e4 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff88807d214000 R15: 0000000000000047
 rtmsg_ifinfo_build_skb+0xdf/0x180 net/core/rtnetlink.c:3890
 rtmsg_ifinfo_event net/core/rtnetlink.c:3922 [inline]
 rtmsg_ifinfo+0x71/0x120 net/core/rtnetlink.c:3931
 __dev_notify_flags+0xde/0x2d0 net/core/dev.c:8887
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929
 dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324
 dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587
 sock_do_ioctl+0x222/0x2f0 net/socket.c:1164
 sock_ioctl+0x4ed/0x6e0 net/socket.c:1267
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 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: 0033:0x7f10167e1749
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:00007f1014a48038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1016a37fa0 RCX: 00007f10167e1749
RDX: 0000200000000080 RSI: 0000000000008914 RDI: 000000000000000a
RBP: 00007f1016865f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1016a38038 R14: 00007f1016a37fa0 R15: 00007fff4b385478
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/02 16:05 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in dev_ioctl
2025/12/23 00:38 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in dev_ioctl
2025/12/13 22:16 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in dev_ioctl
* Struck through repros no longer work on HEAD.