CVE-2024-36936

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().
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc6:*:*:*:*:*:*

History

17 Sep 2025, 22:18

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
References () https://git.kernel.org/stable/c/1c5a1627f48105cbab81d25ec2f72232bfaa8185 - () https://git.kernel.org/stable/c/1c5a1627f48105cbab81d25ec2f72232bfaa8185 - Patch
References () https://git.kernel.org/stable/c/781e34b736014188ba9e46a71535237313dcda81 - () https://git.kernel.org/stable/c/781e34b736014188ba9e46a71535237313dcda81 - Patch
References () https://git.kernel.org/stable/c/e115c1b5de55a105c75aba8eb08301c075fa4ef4 - () https://git.kernel.org/stable/c/e115c1b5de55a105c75aba8eb08301c075fa4ef4 - Patch
First Time Linux linux Kernel
Linux
CPE cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:-:*:*:*:*:*:*
CWE CWE-667

21 Nov 2024, 09:22

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/1c5a1627f48105cbab81d25ec2f72232bfaa8185 - () https://git.kernel.org/stable/c/1c5a1627f48105cbab81d25ec2f72232bfaa8185 -
References () https://git.kernel.org/stable/c/781e34b736014188ba9e46a71535237313dcda81 - () https://git.kernel.org/stable/c/781e34b736014188ba9e46a71535237313dcda81 -

10 Oct 2024, 12:15

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/e115c1b5de55a105c75aba8eb08301c075fa4ef4 -
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: efi/unaccepted: toque el bloqueo suave durante la aceptación de la memoria. El commit 50e782a86c98 ("efi/unaccepted: solucione los bloqueos suaves causados por la aceptación de la memoria paralela") ha liberado el bloqueo de giro para que otras CPU puedan usar la memoria. aceptación en paralelo y no activa el bloqueo suave en otras CPU. Sin embargo, el bloqueo suave se mostró de forma intermitente si la memoria del TD invitado es grande y el tiempo de espera del bloqueo suave se establece en 1 segundo: RIP: 0010:_raw_spin_unlock_irqrestore Seguimiento de llamadas:? __hrtimer_run_queues ? hrtimer_interrupt? watchdog_timer_fn? __sysvec_apic_timer_interrupt? __pfx_watchdog_timer_fn? sysvec_apic_timer_interrupt ? __hrtimer_run_queues ? hrtimer_interrupt? asm_sysvec_apic_timer_interrupt? _raw_spin_unlock_irqrestore? __sysvec_apic_timer_interrupt? sysvec_apic_timer_interrupt aceptar_memoria 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 Cuando el irq local está habilitado al final de Accept_memory(), el bloqueo suave detecta que el mecanismo de vigilancia en una sola CPU no ha sido alimentado por un tiempo. Es decir, incluso otras CPU no serán bloqueadas por spinlock, la CPU actual podría apestar con el irq local deshabilitado por un tiempo, lo que perjudica no solo al nmi watchdog sino también al softlockup. Chao Gao señaló que la aceptación de la memoria podría llevar mucho tiempo y hubo un informe similar antes. Por lo tanto, para evitar cualquier detección de softlocup durante esta etapa, proporcione al softlockup una bandera para omitir la verificación del tiempo de espera al final de Accept_memory(), invocando touch_softlockup_watchdog().

30 May 2024, 16:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-30 16:15

Updated : 2025-09-17 22:18


NVD link : CVE-2024-36936

Mitre link : CVE-2024-36936

CVE.ORG link : CVE-2024-36936


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-667

Improper Locking