syzbot


INFO: rcu detected stall in kcompactd (2)

Status: upstream: reported C repro on 2024/06/01 03:17
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+54594368fbd5a4f1754a@syzkaller.appspotmail.com
First crash: 26d, last: 20d
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] INFO: rcu detected stall in kcompactd (2) 2 (5) 2024/06/01 09:34
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in kcompactd mm 1 311d 311d 0/27 auto-obsoleted due to no activity on 2023/11/10 08:17
linux-6.1 INFO: rcu detected stall in kcompactd 1 6d18h 6d18h 0/3 upstream: reported on 2024/06/11 19:09
upstream BUG: soft lockup in kcompactd kvm 1 959d 955d 0/27 auto-closed as invalid on 2022/01/31 12:36
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/06/11 18:32 23m retest repro upstream report log
2024/06/01 09:07 22m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master report log
2024/06/01 07:01 25m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master error OK

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=9993, q=77 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 1800 (4294972632-4294970832), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 1800 jiffies! g9993 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:27680 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6745
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6924
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194
 rcu_gp_fqs_loop+0x217/0xb00 kernel/rcu/tree.c:2000
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 34 Comm: kcompactd0 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 26 68 80 f6 48 89 df e8 0e e5 80 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 25 27 72 f6 65 8b 05 b6 86 18 75 85 c0 74 16 5b
RSP: 0018:ffffc90000a18248 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff94ca7948 RCX: 1ffffffff2857134
RDX: 0000000000000000 RSI: ffffffff8b2cade0 RDI: ffffffff8b8fffc0
RBP: 0000000000000286 R08: 0000000000000001 R09: fffffbfff284d670
R10: ffffffff9426b387 R11: 0000000000000002 R12: ffffffff94ca7940
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888059c72800
FS:  0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff8f455d78 CR3: 0000000049512000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __debug_check_no_obj_freed lib/debugobjects.c:998 [inline]
 debug_check_no_obj_freed+0x328/0x600 lib/debugobjects.c:1019
 slab_free_hook mm/slub.c:2162 [inline]
 slab_free mm/slub.c:4436 [inline]
 kfree+0x284/0x3b0 mm/slub.c:4557
 ieee80211_inform_bss+0x76e/0x1140 net/mac80211/scan.c:160
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0x893/0x1f70 net/wireless/scan.c:2277
 cfg80211_inform_bss_data+0x205/0x39d0 net/wireless/scan.c:3101
 cfg80211_inform_bss_frame_data+0x271/0x7c0 net/wireless/scan.c:3191
 ieee80211_bss_info_update+0x311/0xab0 net/mac80211/scan.c:226
 ieee80211_scan_rx+0x47c/0xad0 net/mac80211/scan.c:340
 __ieee80211_rx_handle_packet net/mac80211/rx.c:5222 [inline]
 ieee80211_rx_list+0x1be1/0x2e90 net/mac80211/rx.c:5459
 ieee80211_rx_napi+0xdd/0x400 net/mac80211/rx.c:5482
 ieee80211_rx include/net/mac80211.h:5093 [inline]
 ieee80211_tasklet_handler+0xd6/0x130 net/mac80211/main.c:438
 tasklet_action_common.constprop.0+0x24c/0x3e0 kernel/softirq.c:785
 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu kernel/softirq.c:637 [inline]
 irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:free_object lib/debugobjects.c:423 [inline]
RIP: 0010:debug_object_free+0x294/0x500 lib/debugobjects.c:866
Code: 4d 89 6c 24 08 48 8b 7c 24 10 48 89 ce 48 b8 00 01 00 00 00 00 ad de 48 89 03 48 83 c0 22 48 89 43 08 e8 ff 6b 61 06 48 89 df <e8> e7 d0 ff ff 0f b6 05 e0 df 3f 10 84 c0 0f 85 13 fe ff ff 8b 05
RSP: 0018:ffffc90000aa7bb0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: ffff88805aa2d070 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8b2cade0 RDI: ffff88805aa2d070
RBP: ffffc90000aa7ca0 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff8fe45e57 R11: 0000000000000000 R12: ffff888021d9be00
R13: ffffffff94d302d8 R14: ffffc90000aa7cd0 R15: 1ffff92000154f7a
 destroy_timer_on_stack kernel/time/timer.c:866 [inline]
 schedule_timeout+0x14f/0x2a0 kernel/time/timer.c:2585
 kcompactd+0xad3/0xde0 mm/compaction.c:3199
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/28 03:05 upstream 2bfcfd584ff5 f550015e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcompactd
2024/05/28 17:14 upstream 2bfcfd584ff5 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in kcompactd
2024/05/23 01:00 linux-next 124cfbcd6d18 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kcompactd
* Struck through repros no longer work on HEAD.