### [CVE-2024-26712](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-26712) ![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue) ![](https://img.shields.io/static/v1?label=Version&message=663c0c9496a6%3C%20230e89b5ad0a%20&color=brighgreen) ![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen) ### Description In the Linux kernel, the following vulnerability has been resolved:powerpc/kasan: Fix addr error caused by page alignmentIn kasan_init_region, when k_start is not page aligned, at the begin offor 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 bymemblock_alloc, which will not be reserved by memblock_reserve later, itwill 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 beforememblock_alloc() to ensure the validity of the VA address. ### POC #### Reference No PoCs from references. #### Github - https://github.com/fkie-cad/nvd-json-data-feeds