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INFO: rcu detected stall in dcache_dir_open (2)

Status: auto-obsoleted due to no activity on 2025/07/29 09:09
Subsystems: mm
[Documentation on labels]
First crash: 127d, last: 120d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in dcache_dir_open mm 1 4 217d 299d 0/29 auto-obsoleted due to no activity on 2025/04/23 01:08

Sample crash report:
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5849/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=21297, q=497 ncpus=2)
task:syz-executor    state:R  running task     stack:20920 pid:5849  tgid:5849  ppid:5826   task_flags:0x400140 flags:0x20000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x90 kernel/kcov.c:294
Code: 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 40 75 92 65 8b 15 e8 7e b5 10 81 e2 00 01 ff 00
RSP: 0018:ffffc9000409f4d0 EFLAGS: 00000293
RAX: ffffffff822c9aa6 RBX: 0000000000000000 RCX: ffff888064275a00
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000005
RBP: 0000000000000008 R08: ffff88801bc6580f R09: 1ffff1100378cb01
R10: dffffc0000000000 R11: ffffed100378cb02 R12: ffff88801bc65810
R13: 0000000000000005 R14: 0000000000031449 R15: 000000000003144d
 __page_table_check_zero+0x1d6/0x510 mm/page_table_check.c:139
 page_table_check_free include/linux/page_table_check.h:41 [inline]
 free_pages_prepare mm/page_alloc.c:1263 [inline]
 __free_frozen_pages+0xb22/0xcd0 mm/page_alloc.c:2725
 discard_slab mm/slub.c:2730 [inline]
 __put_partials+0x161/0x1c0 mm/slub.c:3199
 put_cpu_partial+0x17c/0x250 mm/slub.c:3274
 __slab_free+0x2f7/0x400 mm/slub.c:4526
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4161 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4229
 __d_alloc+0x31/0x6f0 fs/dcache.c:1681
 d_alloc_anon fs/dcache.c:1778 [inline]
 d_alloc_cursor+0x44/0xd0 fs/dcache.c:1784
 dcache_dir_open+0x41/0x80 fs/libfs.c:91
 do_dentry_open+0xdf0/0x1970 fs/open.c:956
 vfs_open+0x3b/0x340 fs/open.c:1086
 do_open fs/namei.c:3880 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4039
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_compat_sys_openat fs/open.c:1506 [inline]
 __se_compat_sys_openat fs/open.c:1504 [inline]
 __ia32_compat_sys_openat+0x131/0x160 fs/open.c:1504
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70ee539
RSP: 002b:00000000f75afd50 EFLAGS: 00000206 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f72d6b66
RDX: 0000000000098800 RSI: 0000000000000000 RDI: 00000000f7452ff4
RBP: 00000000000000df R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 9516 jiffies! g21297 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:27032 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6947
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6971
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
 prepare_to_swait_event+0x341/0x380 kernel/sched/swait.c:119
 rcu_gp_fqs_loop+0x2cc/0x1540 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 6b 12 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 7124dca036b32000 RBX: ffffffff81973da8 RCX: 7124dca036b32000
RDX: 0000000000000001 RSI: ffffffff8d748ffc RDI: ffffffff8bc1cde0
RBP: ffffc90000197f20 R08: ffff8880b8932b5b R09: 1ffff1101712656b
R10: dffffc0000000000 R11: ffffed101712656c R12: ffffffff8f7ec970
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b40
FS:  0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000080152018 CR3: 00000000311ba000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>
batman_adv: batadv0: Local translation table size (80) exceeds maximum packet size (-320); Ignoring new local tt entry: aa:aa:aa:aa:aa:1b
batman_adv: batadv0: Local translation table size (80) exceeds maximum packet size (-320); Ignoring new local tt entry: aa:aa:aa:aa:aa:3e
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
batman_adv: batadv0: Local translation table size (80) exceeds maximum packet size (-320); Ignoring new local tt entry: aa:aa:aa:aa:aa:0c
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/30 09:00 upstream 8bac8898fe39 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in dcache_dir_open
2025/04/23 05:59 net-next 0e0a7e3719bc 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in dcache_dir_open
* Struck through repros no longer work on HEAD.