Fixed
Created: Apr 3, 2024
Updated: Jun 14, 2024
Resolved Date: Jun 14, 2024
Found In Version: 10.21.20.1
Fix Version: 10.21.20.22
Severity: Standard
Applicable for: Wind River Linux LTS 21
Component/s: Kernel
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.
CREATE(Triage):(User=admin) [CVE-2024-26712 (https://nvd.nist.gov/vuln/detail/CVE-2024-26712)