CVE-2024-26712

Technical Description

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

*/

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References