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INFO: rcu detected stall in sys_munmap

Status: auto-obsoleted due to no activity on 2024/10/31 01:03
Reported-by: syzbot+423cfcbc488758c9c65e@syzkaller.appspotmail.com
First crash: 663d, last: 663d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sys_munmap 1 7 137d 308d 0/2 auto-obsoleted due to no activity on 2026/04/09 22:56
upstream INFO: rcu detected stall in sys_munmap mm kasan 1 1 982d 982d 0/29 auto-obsoleted due to no activity on 2023/11/06 05:09
linux-5.15 INFO: rcu detected stall in sys_munmap 1 1 304d 304d 0/3 auto-obsoleted due to no activity on 2025/10/24 12:55
linux-6.1 INFO: rcu detected stall in sys_munmap (2) origin:upstream 1 C error 23 18d 409d 0/3 upstream: reported C repro on 2025/04/02 07:15
upstream INFO: rcu detected stall in sys_munmap (2) mm 1 C error error 43 19d 267d 0/29 upstream: reported C repro on 2025/08/22 04:15
linux-6.6 INFO: rcu detected stall in sys_munmap (2) 1 1 5d15h 5d15h 0/2 upstream: reported on 2026/05/11 10:40

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9193/1:b..l
	(detected by 1, t=10502 jiffies, g=50837, q=148 ncpus=2)
task:syz.1.1438      state:R  running task     stack:23928 pid:9193  ppid:5232   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6873
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:lock_is_held_type+0x137/0x180
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000511f5a0 EFLAGS: 00000206
RAX: 7d2bd68cb8668800 RBX: 0000000000000001 RCX: 0000000080000000
RDX: ffffc9000a95a000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d48a0
RBP: 0000000000000001 R08: ffffffff81ecc94a R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246
R13: ffff88805d908000 R14: 00000000ffffffff R15: ffffffff8d12ad40
 lookup_page_ext mm/page_ext.c:277 [inline]
 page_ext_get+0x18e/0x2a0 mm/page_ext.c:158
 __page_table_check_zero+0x139/0x4b0 mm/page_table_check.c:146
 page_table_check_free include/linux/page_table_check.h:46 [inline]
 free_pages_prepare mm/page_alloc.c:1445 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf73/0x1120 mm/page_alloc.c:3362
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3503
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361
 unmap_region+0x29f/0x2f0 mm/mmap.c:2332
 do_mas_align_munmap+0xec8/0x15f0 mm/mmap.c:2582
 do_mas_munmap+0x246/0x2b0 mm/mmap.c:2640
 __vm_munmap+0x268/0x370 mm/mmap.c:2917
 __do_sys_munmap mm/mmap.c:2942 [inline]
 __se_sys_munmap mm/mmap.c:2939 [inline]
 __x64_sys_munmap+0x5c/0x70 mm/mmap.c:2939
 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: 0033:0x7f3574f75fa7
RSP: 002b:00007f3575d0ae28 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f3574f75fa7
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007f356b3f7000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009687
R10: 00000000200259c2 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f3575d0af00 R14: 00007f3575d0aec0 R15: 00007f356b3f7000
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 9949 jiffies! g50837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=25177
rcu: rcu_preempt kthread starved for 9950 jiffies! g50837 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:25528 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 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:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567
Code: 0b f5 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 f4 c9 fb f6 0f 1f 44 00 00 e8 4a 07 f5 f6 0f 00 2d 63 d5 b1 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 3b 8f 4c f7
RSP: 0018:ffffc90000177b80 EFLAGS: 000002d3
RAX: ffffffff8a959336 RBX: 0000000000000000 RCX: ffff888012739dc0
RDX: 0000000000000000 RSI: ffffffff8aec0240 RDI: ffffffff8b3d48a0
RBP: ffffc90000177c10 R08: ffffffff8a959318 R09: ffffed10024e73b9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002ef70
R13: ffff888143e8c004 R14: ffffc90000177ba0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f737d2236c0 CR3: 00000000220ba000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:704
 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3ce/0x680 kernel/sched/idle.c:303
 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/23 01:03 linux-6.1.y 9b3f9a5b12dc 708c10c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_munmap
* Struck through repros no longer work on HEAD.