syzbot


INFO: rcu detected stall in syscall_exit_to_user_mode

Status: upstream: reported C repro on 2023/04/07 08:31
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+a5ddd0a69ba3bcb6ca90@syzkaller.appspotmail.com
First crash: 414d, last: 1d13h
Bug presence (1)
Date Name Commit Repro Result
2023/12/28 upstream (ToT) f5837722ffec C [report] INFO: rcu detected stall in corrupted
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in syscall_exit_to_user_mode cgroups mm 78 821d 1001d 20/26 fixed on 2022/03/08 16:11
upstream INFO: rcu detected stall in syscall_exit_to_user_mode (2) usb C inconclusive 266 11h17m 536d 0/26 upstream: reported C repro on 2022/12/05 19:46
linux-5.15 INFO: rcu detected stall in syscall_exit_to_user_mode origin:upstream C 101 3h36m 272d 0/3 upstream: reported C repro on 2023/08/26 22:23
android-5-15 BUG: soft lockup in syscall_exit_to_user_mode origin:lts C 9 1d21h 1d21h 0/2 upstream: reported C repro on 2024/05/23 18:26

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6141, q=15 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294966677-4294956174), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g6141 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:25528 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3593 Comm: syz-executor290 Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:irq_exit_rcu+0x0/0x20 kernel/softirq.c:662
Code: 80 c1 03 38 c1 7c 88 48 89 df e8 1b e6 8d 00 e9 7b ff ff ff 66 0f 1f 44 00 00 e8 bb ae 36 09 e9 16 ff ff ff 66 0f 1f 44 00 00 <e8> 1b 00 00 00 48 c7 c7 a0 fb ea 8a e8 7f b2 36 09 65 ff 0d ac 56
RSP: 0018:ffffc90000007ff0 EFLAGS: 00000082
RAX: 0000000000000000 RBX: ffffc90003e1fa88 RCX: ffffffff813a1811
RDX: 0000000000000000 RSI: ffffffff8ae8e780 RDI: ffffffff8b3d43e0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ce7046
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00005555555b63c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efdc43bd4c0 CR3: 00000000196ca000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: c1 bc f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 fe 8b d5 f6 48 89 df e8 66 c9 d6 f6 e8 31 54 fc f6 fb bf 01 00 00 00 <e8> 56 58 c9 f6 65 8b 05 c7 73 6d 75 85 c0 74 02 5b c3 e8 f4 98 6b
RSP: 0018:ffffc90003e1fb30 EFLAGS: 00000286
RAX: ff3b830cfd931300 RBX: ffff888074da1280 RCX: ffffffff91c93103
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: 0000000000000001
RBP: ffffc90003e1fc70 R08: dffffc0000000000 R09: ffffed100e9b4251
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1100e9b42e3
R13: 000000001c000004 R14: 0000000000000021 R15: ffff888074da1718
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x154b/0x17d0 kernel/signal.c:2865
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efdc43a5e79
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe2e6cf9c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007efdc43a5e79
RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00005555555b6370
R13: 0000000000000003 R14: 00007ffe2e6cfa40 R15: 00007ffe2e6cfa30
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.473 msecs

Crashes (31):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/09 21:33 linux-6.1.y 909ba1f1b414 05079661 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/01 21:43 linux-6.1.y dcbc050cb0d3 3ba885bc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/04/18 04:52 linux-6.1.y 6741e066ec76 acc528cb .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/03/23 16:46 linux-6.1.y d7543167affd 0ea90952 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/02/25 16:42 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/01/22 03:29 linux-6.1.y 8fd7f4462453 9bd8dcda .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/12/28 04:12 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/24 01:28 linux-6.1.y 4078fa637fcd 8f98448e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/22 14:51 linux-6.1.y 4078fa637fcd 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/16 20:19 linux-6.1.y 909ba1f1b414 c2e07261 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/04 05:42 linux-6.1.y 909ba1f1b414 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/03 05:28 linux-6.1.y 909ba1f1b414 ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in syscall_exit_to_user_mode
2024/05/02 23:15 linux-6.1.y 909ba1f1b414 ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/04/22 17:15 linux-6.1.y 6741e066ec76 36c961ad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/04/18 19:13 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/04/04 13:30 linux-6.1.y 347385861c50 0ee3535e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/02/14 19:33 linux-6.1.y f1bb70486c9c d9b1cdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/02/13 18:48 linux-6.1.y f1bb70486c9c e66542d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/01/17 17:27 linux-6.1.y fec3b1451d5f c9a1c95b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2024/01/12 20:06 linux-6.1.y 7c58bfa711cb 551587c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/12/20 15:36 linux-6.1.y ba6f5fb46511 de21eb89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/12/20 04:34 linux-6.1.y ba6f5fb46511 3ad490ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/11/29 02:22 linux-6.1.y 6ac30d748bb0 1adfb6f6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/11/12 02:35 linux-6.1.y fb2635ac69ab 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/10/09 18:07 linux-6.1.y ecda77b46871 3c53c7d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/08/28 01:34 linux-6.1.y 024f76bca9d0 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/08/26 08:44 linux-6.1.y 802aacbbffe2 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/08/25 14:09 linux-6.1.y 802aacbbffe2 03d9c195 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/08/09 02:39 linux-6.1.y 0a4a7855302d 9552ae77 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/07/11 22:41 linux-6.1.y 61fd484b2cf6 2f19aa4f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
2023/04/07 08:31 linux-6.1.y 543aff194ab6 00ce4c67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in syscall_exit_to_user_mode
* Struck through repros no longer work on HEAD.