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CVE-2024-26712

MEDIUMCVSS 4.4/10EPSS 0.22%

Last modified

CVE-2024-26712 is a medium-severity vulnerability rated 4.4/10 on the CVSS scale. 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.. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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 */ 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.

Metrics

CVSS 3.1
4.4/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.22%

12.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.4, < 5.10.210—
LinuxLinux Kernel>= 5.11, < 5.15.149—
LinuxLinux Kernel>= 5.16, < 6.1.79—
LinuxLinux Kernel>= 6.2, < 6.6.18—
LinuxLinux Kernel>= 6.7, < 6.7.6—
LinuxLinux Kernel6.8Rc1
DebianDebian Linux10.0—

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2024-26712?
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.
How severe is CVE-2024-26712?
CVE-2024-26712 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.
How do I fix CVE-2024-26712?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST