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INFO: rcu detected stall in sys_syslog

Status: upstream: reported on 2024/05/26 09:39
Reported-by: syzbot+f41fea23bf13656ef7cb@syzkaller.appspotmail.com
First crash: 24d, last: 23d
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_syslog kernel 1 281d 281d 0/27 auto-obsoleted due to no activity on 2023/12/11 00:13
upstream INFO: rcu detected stall in sys_syslog (2) input usb syz 3 4h09m 120d 0/27 upstream: reported syz repro on 2024/02/20 16:45
linux-6.1 INFO: rcu detected stall in sys_syslog 1 13d 13d 0/3 upstream: reported on 2024/06/06 06:03
android-5-15 BUG: soft lockup in sys_syslog origin:lts C 10 24d 73d 0/2 upstream: reported C repro on 2024/04/07 08:50

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=d5f/1/0x4000000000000000 softirq=33936/33936 fqs=0 
	(detected by 0, t=10502 jiffies, g=46265, q=85)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 11337 Comm: syz-executor.3 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:do_raw_spin_unlock+0x3/0x8b0 kernel/locking/spinlock_debug.c:138
Code: 07 80 c1 03 38 c1 0f 8c 2c ff ff ff e8 a6 05 66 00 e9 22 ff ff ff e8 0c c8 b9 08 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 <41> 56 41 55 41 54 53 48 83 ec 28 49 89 ff 48 bb 00 00 00 00 00 fc
RSP: 0018:ffffc90000dd0c98 EFLAGS: 00000046
RAX: 1060f35ff858c700 RBX: ffff88801d913ae8 RCX: ffffc90000dd0b03
RDX: 0000000000000001 RSI: ffffffff8a8b3c20 RDI: ffff88801d913ae8
RBP: ffff88801d913ae8 R08: dffffc0000000000 R09: fffffbfff1bc8cce
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801d913800
R13: ffff88801d913b40 R14: dffffc0000000000 R15: 17df87fcac000000
FS:  00007fe8acc136c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000c0 CR3: 000000001adce000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_unlock include/linux/spinlock_api_smp.h:151 [inline]
 _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:403 [inline]
 advance_sched+0x68b/0x940 net/sched/sch_taprio.c:765
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_switch+0x0/0xe0 kernel/kcov.c:297
Code: 39 c8 77 1e 48 c7 44 11 08 07 00 00 00 48 89 7c 11 10 48 89 74 11 18 4c 89 44 11 20 49 ff c2 4c 89 12 c3 0f 1f 80 00 00 00 00 <41> 57 41 56 41 54 53 48 8b 46 08 48 83 c0 f8 48 c1 c0 3d 48 83 f8
RSP: 0018:ffffc900030479c0 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff8c8190b8 RCX: ffff888078ab3b80
RDX: 0000000000000000 RSI: ffffffff8c917bf0 RDI: 0000000000000002
RBP: 00000000fffff321 R08: ffffffff816711cb R09: fffffbfff1903218
R10: 0000000000000000 R11: dffffc0000000001 R12: 80000000fffff321
R13: 00000000fffff321 R14: 0000000000003963 R15: 0000000000000002
 desc_read+0x168/0x3d0 kernel/printk/printk_ringbuffer.c:445
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1752 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1800 [inline]
 _prb_read_valid+0x2a6/0xbd0 kernel/printk/printk_ringbuffer.c:1880
 prb_read_valid_info+0x125/0x170 kernel/printk/printk_ringbuffer.c:1963
 do_syslog+0x6e9/0x940 kernel/printk/printk.c:1747
 __do_sys_syslog kernel/printk/printk.c:1771 [inline]
 __se_sys_syslog kernel/printk/printk.c:1769 [inline]
 __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe8ae6c0ee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007fe8acc130c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007fe8ae7f0050 RCX: 00007fe8ae6c0ee9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: 00007fe8ae70d49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fe8ae7f0050 R15: 00007ffe48221f38
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g46265 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=20560
rcu: rcu_preempt kthread starved for 10502 jiffies! g46265 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27000 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
 </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: 11337 Comm: syz-executor.3 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__lock_release kernel/locking/lockdep.c:5279 [inline]
RIP: 0010:lock_release+0x704/0x9a0 kernel/locking/lockdep.c:5643
Code: e9 fa f9 ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 2e fa ff ff 48 89 df e8 09 52 67 00 e9 21 fa ff ff 48 8d 8c 24 80 00 00 00 <80> e1 07 80 c1 03 38 c1 0f 8c 94 fa ff ff 48 8d bc 24 80 00 00 00
RSP: 0018:ffffc90000dd0b60 EFLAGS: 00000002
RAX: 0000000000000004 RBX: 0000000000000046 RCX: ffffc90000dd0be0
RDX: 1ffff920001ba17c RSI: ffffffff8a8b3780 RDI: ffffffff8ad8f6c0
RBP: ffffc90000dd0ca0 R08: dffffc0000000000 R09: fffffbfff1bc8cce
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920001ba178
R13: ffff888078ab3b80 R14: ffffc90000dd0c10 R15: dffffc0000000000
FS:  00007fe8acc136c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200000c0 CR3: 000000001adce000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline]
 _raw_spin_unlock+0x12/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:403 [inline]
 advance_sched+0x68b/0x940 net/sched/sch_taprio.c:765
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_switch+0x0/0xe0 kernel/kcov.c:297
Code: 39 c8 77 1e 48 c7 44 11 08 07 00 00 00 48 89 7c 11 10 48 89 74 11 18 4c 89 44 11 20 49 ff c2 4c 89 12 c3 0f 1f 80 00 00 00 00 <41> 57 41 56 41 54 53 48 8b 46 08 48 83 c0 f8 48 c1 c0 3d 48 83 f8
RSP: 0018:ffffc900030479c0 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff8c8190b8 RCX: ffff888078ab3b80
RDX: 0000000000000000 RSI: ffffffff8c917bf0 RDI: 0000000000000002
RBP: 00000000fffff321 R08: ffffffff816711cb R09: fffffbfff1903218
R10: 0000000000000000 R11: dffffc0000000001 R12: 80000000fffff321
R13: 00000000fffff321 R14: 0000000000003963 R15: 0000000000000002
 desc_read+0x168/0x3d0 kernel/printk/printk_ringbuffer.c:445
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1752 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1800 [inline]
 _prb_read_valid+0x2a6/0xbd0 kernel/printk/printk_ringbuffer.c:1880
 prb_read_valid_info+0x125/0x170 kernel/printk/printk_ringbuffer.c:1963
 do_syslog+0x6e9/0x940 kernel/printk/printk.c:1747
 __do_sys_syslog kernel/printk/printk.c:1771 [inline]
 __se_sys_syslog kernel/printk/printk.c:1769 [inline]
 __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe8ae6c0ee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007fe8acc130c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007fe8ae7f0050 RCX: 00007fe8ae6c0ee9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: 00007fe8ae70d49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fe8ae7f0050 R15: 00007ffe48221f38
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/27 14:05 linux-5.15.y c61bd26ae81a 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_syslog
2024/05/26 09:38 linux-5.15.y c61bd26ae81a a10a183e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_syslog
* Struck through repros no longer work on HEAD.