efi/unaccepted:内存接受期间触摸软锁定(CVE-2024-36936)

CVE编号

CVE-2024-36936

利用情况

暂无

补丁情况

N/A

披露时间

2024-05-31
漏洞描述
In the Linux kernel, the following vulnerability has been resolved:

efi/unaccepted: touch soft lockup during memory accept

Commit 50e782a86c98 ("efi/unaccepted: Fix soft lockups caused by
parallel memory acceptance") has released the spinlock so other CPUs can
do memory acceptance in parallel and not triggers softlockup on other
CPUs.

However the softlock up was intermittent shown up if the memory of the
TD guest is large, and the timeout of softlockup is set to 1 second:

RIP: 0010:_raw_spin_unlock_irqrestore
Call Trace:
? __hrtimer_run_queues
<IRQ>
? hrtimer_interrupt
? watchdog_timer_fn
? __sysvec_apic_timer_interrupt
? __pfx_watchdog_timer_fn
? sysvec_apic_timer_interrupt
</IRQ>
? __hrtimer_run_queues
<TASK>
? hrtimer_interrupt
? asm_sysvec_apic_timer_interrupt
? _raw_spin_unlock_irqrestore
? __sysvec_apic_timer_interrupt
? sysvec_apic_timer_interrupt
accept_memory
try_to_accept_memory
do_huge_pmd_anonymous_page
get_page_from_freelist
__handle_mm_fault
__alloc_pages
__folio_alloc
? __tdx_hypercall
handle_mm_fault
vma_alloc_folio
do_user_addr_fault
do_huge_pmd_anonymous_page
exc_page_fault
? __do_huge_pmd_anonymous_page
asm_exc_page_fault
__handle_mm_fault

When the local irq is enabled at the end of accept_memory(), the
softlockup detects that the watchdog on single CPU has not been fed for
a while. That is to say, even other CPUs will not be blocked by
spinlock, the current CPU might be stunk with local irq disabled for a
while, which hurts not only nmi watchdog but also softlockup.

Chao Gao pointed out that the memory accept could be time costly and
there was similar report before. Thus to avoid any softlocup detection
during this stage, give the softlockup a flag to skip the timeout check
at the end of accept_memory(), by invoking touch_softlockup_watchdog().
解决建议
建议您更新当前系统或软件至最新版,完成漏洞的修复。
受影响软件情况
# 类型 厂商 产品 版本 影响面
1
运行在以下环境
系统 debian_10 linux * Up to
(excluding)
4.19.304-1
运行在以下环境
系统 debian_11 linux * Up to
(excluding)
5.10.216-1
运行在以下环境
系统 debian_12 linux * Up to
(excluding)
6.1.90-1
CVSS3评分
N/A
  • 攻击路径
    N/A
  • 攻击复杂度
    N/A
  • 权限要求
    N/A
  • 影响范围
    N/A
  • 用户交互
    N/A
  • 可用性
    N/A
  • 保密性
    N/A
  • 完整性
    N/A
CWE-ID 漏洞类型
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