syzbot

 sign-in | mailing list | source | docs
🐞 Open [801]
🐞 Fixed [135]
🐞 Invalid [910]
⬇ Missing Backports [76]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in vm_area_alloc

Status: auto-obsoleted due to no activity on 2025/07/06 19:56
Reported-by: syzbot+aa1f46413daf9c0e74b4@syzkaller.appspotmail.com
First crash: 207d, last: 207d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in vm_area_alloc (4) bpf 1 1 566d 566d 0/29 auto-obsoleted due to no activity on 2024/07/03 04:13
upstream INFO: rcu detected stall in vm_area_alloc (2) mm 1 1 2113d 2113d 0/29 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in vm_area_alloc (3) mm 1 2 663d 664d 0/29 auto-obsoleted due to no activity on 2024/03/27 19:02
upstream INFO: rcu detected stall in vm_area_alloc mm 1 3 2148d 2150d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in vm_area_alloc (6) mm bpf 1 syz error 4 73d 144d 0/29 upstream: reported syz repro on 2025/05/30 07:37
upstream INFO: rcu detected stall in vm_area_alloc (5) bpf mm 1 18 289d 410d 0/29 auto-obsoleted due to no activity on 2025/04/05 06:19
android-6-12 INFO: rcu detected stall in vm_area_alloc 1 1 103d 103d 0/1 auto-obsoleted due to no activity on 2025/10/08 16:56

Sample crash report:
IPVS: sh: UDP 224.0.0.2:0 - no destination available
IPVS: sh: UDP 224.0.0.2:0 - no destination available
IPVS: sh: UDP 224.0.0.2:0 - no destination available
IPVS: sh: UDP 224.0.0.2:0 - no destination available
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9862/1:b..l
	(detected by 0, t=10502 jiffies, g=52181, q=207 ncpus=2)
task:dhcpcd-run-hook state:R  running task     stack:23880 pid:9862  ppid:3916   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 4f 55 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000cb0f7e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92001961f08 RCX: 1ffff92001961ea8
RDX: dffffc0000000000 RSI: ffffffff8b0c2ec0 RDI: ffffffff8b5f6f80
RBP: ffffc9000cb0f938 R08: dffffc0000000000 R09: fffffbfff225724d
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92001961f04
R13: dffffc0000000000 R14: ffffc9000cb0f840 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 get_obj_cgroup_from_current+0xf1/0x280 mm/memcontrol.c:3021
 memcg_slab_pre_alloc_hook mm/slab.h:485 [inline]
 slab_pre_alloc_hook+0x90/0x300 mm/slab.h:715
 slab_alloc_node mm/slub.c:3318 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x4e/0x2d0 mm/slub.c:3422
 vm_area_alloc+0x20/0xe0 kernel/fork.c:459
 __mmap_region mm/mmap.c:2741 [inline]
 mmap_region+0xec2/0x2660 mm/mmap.c:2904
 do_mmap+0x8c5/0xf60 mm/mmap.c:1424
 vm_mmap_pgoff+0x1ca/0x2d0 mm/util.c:520
 ksys_mmap_pgoff+0x4f5/0x6d0 mm/mmap.c:1470
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd2a6651b74
RSP: 002b:00007ffe9f25a7c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ffe9f25a808 RCX: 00007fd2a6651b74
RDX: 0000000000000005 RSI: 0000000000123000 RDI: 00007fd2a63e8000
RBP: 00007ffe9f25af60 R08: 0000000000000003 R09: 0000000000028000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007fd2a66345c0
R13: 00007ffe9f25afe8 R14: 0000000000027f38 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10465 jiffies! g52181 f0x0 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/28 19:56 linux-6.1.y 344a09659766 9a1a9e31 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in vm_area_alloc
* Struck through repros no longer work on HEAD.