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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: 382d, last: 15h47m
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/12/28 upstream (ToT) f5837722ffec C [report] INFO: rcu detected stall in corrupted
2024/04/14 upstream (ToT) 7efd0a74039f C Failed due to an error; will retry later
▶ ▼ 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 788d 969d 20/26 fixed on 2022/03/08 16:11
upstream INFO: rcu detected stall in syscall_exit_to_user_mode (2) usb C inconclusive 203 19h09m 504d 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 48 21h23m 240d 0/3 upstream: reported C repro on 2023/08/26 22:23
android-5-15 BUG: soft lockup in syscall_exit_to_user_mode 1 4d01h 4d01h 0/2 premoderation: reported on 2024/04/19 07:14

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=5853, q=23 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294962653-4294952151), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g5853 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:26400 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3591 Comm: syz-executor181 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7c/0x80 kernel/kcov.c:306
Code: 8d 42 28 4c 39 c8 77 22 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 <c3> 0f 1f 00 4c 8b 04 24 65 48 8b 0d f4 db 77 7e 65 8b 05 f5 db 77
RSP: 0018:ffffc900001e0bb0 EFLAGS: 00000046
RAX: 0000000080010003 RBX: 0000000000400140 RCX: ffff888021a8d940
RDX: ffff888021a8d940 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000100000000 R08: ffffffff81569651 R09: ffffffff8156921c
R10: 0000000000000002 R11: ffff888021a8d940 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888021a8d940 R15: 0000000000000001
FS:  00005555560de480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 00000000789d1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 wants_signal kernel/signal.c:990 [inline]
 complete_signal+0xf1/0xbd0 kernel/signal.c:1013
 send_sigqueue+0x44f/0x720 kernel/signal.c:2003
 posix_timer_event kernel/time/posix-timers.c:354 [inline]
 posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:380
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8c/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 3e be d5 f6 48 89 df e8 a6 fb d6 f6 e8 71 86 fc f6 fb bf 01 00 00 00 <e8> 56 88 c9 f6 65 8b 05 f7 a3 6d 75 85 c0 74 02 5b c3 e8 24 c9 6b
RSP: 0018:ffffc90003c5fb30 EFLAGS: 00000286
RAX: ee5838433330ca00 RBX: ffff888027e83780 RCX: ffffffff91c92103
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: 0000000000000001
RBP: ffffc90003c5fc70 R08: dffffc0000000000 R09: ffffed1004fd06f1
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11004fd0783
R13: 000000001c000004 R14: 0000000000000021 R15: ffff888027e83c18
 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: 0033:0x7f511d30a6e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1d 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:00007ffd85ceeae8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f511d30a6e9
RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000f4240 R08: 00007ffd85ceecf0 R09: 00007ffd85ceecf0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd85ceecf0
R13: 00005555560de430 R14: 00007ffd85ceec10 R15: 00007ffd85ceec00
 </TASK>

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2024/04/22 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.