syzbot


INFO: rcu detected stall in sys_close (5)

Status: fixed on 2023/10/12 12:48
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+e46fbd5289363464bc13@syzkaller.appspotmail.com
Fix commit: 8c21ab1bae94 net/sched: fq_pie: avoid stalls in fq_pie_timer()
First crash: 300d, last: 300d
Cause bisection: introduced by (bisect log) :
commit ec97ecf1ebe485a17cd8395a5f35e6b80b57665a
Author: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Date: Wed Jan 22 18:22:33 2020 +0000

  net: sched: add Flow Queue PIE packet scheduler

Crash: INFO: rcu detected stall in fq_pie_timer (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] net/sched: fq_pie: avoid stalls in fq_pie_timer() 8 (8) 2023/08/31 11:17
[syzbot] [fs?] INFO: rcu detected stall in sys_close (5) 2 (4) 2023/08/30 03:16
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_close (3) kernel 1 667d 667d 0/27 auto-obsoleted due to no activity on 2022/10/25 14:50
upstream INFO: rcu detected stall in sys_close (4) fs 1 591d 591d 0/27 auto-obsoleted due to no activity on 2023/02/13 19:04
linux-5.15 INFO: rcu detected stall in sys_close 1 57d 57d 0/3 upstream: reported on 2024/04/27 21:33
upstream INFO: rcu detected stall in sys_close (7) input usb fs C error 1 70d 66d 0/27 upstream: reported C repro on 2024/04/19 01:14
upstream INFO: rcu detected stall in sys_close fs 1 905d 905d 0/27 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in sys_close (6) fs 3 165d 245d 0/27 auto-obsoleted due to no activity on 2024/04/10 05:01
upstream INFO: rcu detected stall in sys_close (2) fs 3 763d 813d 0/27 auto-closed as invalid on 2022/08/21 03:13
Last patch testing requests (1)
Created Duration User Patch Repo Result
2023/08/29 12:49 21m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master OK log

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236
Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 <a9> 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206
RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0
RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415
 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:__x64_sys_close+0x0/0xf0 fs/open.c:1557
Code: 1a 48 83 ec 80 5b 5d 41 5c c3 e8 eb bb f1 ff e9 73 ff ff ff e8 e1 bb f1 ff eb 8b e8 2a 06 4a 08 66 2e 0f 1f 84 00 00 00 00 00 <f3> 0f 1e fa 55 53 48 89 fb e8 c2 81 9d ff 48 8d 7b 70 48 b8 00 00
RSP: 0018:ffffc9000459ff38 EFLAGS: 00000206
RAX: 0000000000000003 RBX: ffffc9000459ff58 RCX: 1ffffffff1d56e59
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: ffffc9000459ff58
RBP: ffffc9000459ff48 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8eaba457 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 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: 0033:0x7f6b4427b290
Code: ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 80 3d f1 8d 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007ffd4ca6aa18 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f6b4427b290
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000005
RBP: 00000000000f4240 R08: 0000000055d55610 R09: 0000000055d55610
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000220c3
R13: 00007ffd4ca6aa24 R14: 00007ffd4ca6aa40 R15: 00007ffd4ca6aa30
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.831 msecs

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/29 07:32 upstream 727dbda16b83 7ba13a15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_close
* Struck through repros no longer work on HEAD.