syzbot


INFO: rcu detected stall in statfs

Status: fixed on 2023/10/12 12:48
Subsystems: fs
[Documentation on labels]
Fix commit: 8c21ab1bae94 net/sched: fq_pie: avoid stalls in fq_pie_timer()
First crash: 197d, last: 197d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in statfs (2) fs 1 106d 106d 0/26 auto-obsoleted due to no activity on 2024/02/10 01:17

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2659 jiffies s: 3777 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: 5935 Comm: modprobe Not tainted 6.5.0-rc5-syzkaller-00192-g829c6524d672 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x20 kernel/kcov.c:283
Code: 00 00 f3 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 04 00 00 00 e9 1a ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 8b 0c 24 <48> 89 f2 48 89 fe bf 06 00 00 00 e9 f8 fe ff ff 0f 1f 84 00 00 00
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000202
RAX: 000000a7c5ac471b RBX: 0000000002af31dc RCX: ffffffff88582e06
RDX: 0000000000006d1f RSI: 000000a7c5ac471b RDI: 0000000000000000
RBP: 000000a7c5ac471b R08: 0000000000000005 R09: 00000000000f4240
R10: 0000000000002710 R11: 0000000000000000 R12: 00000000000186a0
R13: 0000000000000003 R14: 000000000044b82f R15: 0000000000000000
FS:  00007f319234d380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f31923be723 CR3: 00000000330b1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x296/0x850 net/sched/sch_pie.c:345
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x764/0xb10 kernel/time/timer.c:2022
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 5c 31 f7 48 89 df e8 7e db 31 f7 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f <bf> 01 00 00 00 e8 25 7e 23 f7 65 8b 05 f6 0b ce 75 85 c0 74 12 5b
RSP: 0018:ffffc900033ffbe0 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff9238ff10 RCX: 1ffffffff1d56db9
RDX: 0000000000000000 RSI: ffffffff8a6c80a0 RDI: ffffffff8ac811a0
RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8eab9f57 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000015ec8 R14: 0000000000000000 R15: 0000000000000000
 __debug_check_no_obj_freed lib/debugobjects.c:1042 [inline]
 debug_check_no_obj_freed+0x245/0x4c0 lib/debugobjects.c:1063
 slab_free_hook mm/slub.c:1767 [inline]
 slab_free_freelist_hook+0x182/0x1e0 mm/slub.c:1818
 slab_free mm/slub.c:3801 [inline]
 kmem_cache_free+0xf0/0x490 mm/slub.c:3823
 putname fs/namei.c:273 [inline]
 putname+0x101/0x140 fs/namei.c:259
 user_path_at_empty+0x4c/0x60 fs/namei.c:2909
 user_path_at include/linux/namei.h:57 [inline]
 user_statfs+0xa3/0x180 fs/statfs.c:103
 __do_sys_statfs+0x8a/0x100 fs/statfs.c:195
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f31924a168a
Code: c8 ff c3 b8 03 01 00 00 0f 05 48 3d 00 f0 ff ff 76 10 48 8b 15 8f a7 0d 00 f7 d8 64 89 02 48 83 c8 ff c3 b8 89 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 6f a7 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffd4934dc38 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
RAX: ffffffffffffffda RBX: 00007f31923c64f8 RCX: 00007f31924a168a
RDX: 00007f31923c819c RSI: 00007ffd4934dcb0 RDI: 00007f31923be723
RBP: 00007f31923be723 R08: 0000000000000000 R09: 000000000000000d
R10: 00007ffd4934da60 R11: 0000000000000246 R12: 00007ffd4934dcb0
R13: 00007ffd4934de28 R14: 00007ffd4934de50 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/13 05:06 net 829c6524d672 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in statfs
* Struck through repros no longer work on HEAD.