CVE-2024-26712

powerpc/kasan: Fix addr error caused by page alignment

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

powerpc/kasan: Fix addr error caused by page alignment

In kasan_init_region, when k_start is not page aligned, at the begin of
for loop, k_cur = k_start & PAGE_MASK is less than k_start, and then
`va = block + k_cur - k_start` is less than block, the addr va is invalid,
because the memory address space from va to block is not alloced by
memblock_alloc, which will not be reserved by memblock_reserve later, it
will be used by other places.

As a result, memory overwriting occurs.

for example:
int __init __weak kasan_init_region(void *start, size_t size)
{
[...]
/* if say block(dcd97000) k_start(feef7400) k_end(feeff3fe) */
block = memblock_alloc(k_end - k_start, PAGE_SIZE);
[...]
for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
/* at the begin of for loop
* block(dcd97000) va(dcd96c00) k_cur(feef7000) k_start(feef7400)
* va(dcd96c00) is less than block(dcd97000), va is invalid
*/
void *va = block + k_cur - k_start;
[...]
}
[...]
}

Therefore, page alignment is performed on k_start before
memblock_alloc() to ensure the validity of the VA address.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: powerpc/kasan: corrige el error de dirección causado por la alineación de la página En kasan_init_region, cuando k_start no está alineado con la página, al comienzo del bucle for, k_cur = k_start y PAGE_MASK es menor que k_start. y luego `va = block + k_cur - k_start` es menor que block, la dirección va no es válida, porque memblock_alloc no asigna el espacio de direcciones de memoria de va al bloque, que no será reservado por memblock_reserve más adelante, se utilizará por otros lugares. Como resultado, se produce una sobrescritura de la memoria. por ejemplo: int __init __weak kasan_init_region(void *start, size_t size) { [...] /* if say block(dcd97000) k_start(feef7400) k_end(feeff3fe) */ block = memblock_alloc(k_end - k_start, PAGE_SIZE); [...] for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) { /* al comienzo del bucle for * block(dcd97000) va(dcd96c00) k_cur(feef7000) k_start(feef7400) * va (dcd96c00) es menor que block(dcd97000), va no es válido */ void *va = block + k_cur - k_start; [...] } [...] } Por lo tanto, la alineación de la página se realiza en k_start antes de memblock_alloc() para garantizar la validez de la dirección VA.

*Credits: N/A

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Scope

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* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-19 CVE Reserved
2024-04-03 CVE Published
2024-04-04 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (9)

URL	Tag	Source
https://git.kernel.org/stable/c/663c0c9496a69f80011205ba3194049bcafd681d	Vuln. Introduced
https://git.kernel.org/stable/c/5ce93076d8ee2a0fac3ad4adbd2e91b6197146db	Vuln. Introduced
https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/230e89b5ad0a33f530a2a976b3e5e4385cb27882	2024-02-23
https://git.kernel.org/stable/c/2738e0aa2fb24a7ab9c878d912dc2b239738c6c6	2024-02-23
https://git.kernel.org/stable/c/0c09912dd8387e228afcc5e34ac5d79b1e3a1058	2024-02-23
https://git.kernel.org/stable/c/0516c06b19dc64807c10e01bb99b552bdf2d7dbe	2024-02-23
https://git.kernel.org/stable/c/70ef2ba1f4286b2b73675aeb424b590c92d57b25	2024-02-23
https://git.kernel.org/stable/c/4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0	2024-02-05

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.10.210 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.10.210"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 5.15.149 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.15.149"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 6.1.79 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 6.1.79"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 6.6.18 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 6.6.18"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 6.7.6 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 6.7.6"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.4 < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 6.8"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				5.3.6 Search vendor "Linux" for product "Linux Kernel" and version "5.3.6"		en		Affected