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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
663c0c9496a69f80011205ba3194049bcafd681d to < 230e89b5ad0a33f530a2a976b3e5e4385cb27882affected663c0c9496a69f80011205ba3194049bcafd681d to < 2738e0aa2fb24a7ab9c878d912dc2b239738c6c6affected663c0c9496a69f80011205ba3194049bcafd681d to < 0c09912dd8387e228afcc5e34ac5d79b1e3a1058affected663c0c9496a69f80011205ba3194049bcafd681d to < 0516c06b19dc64807c10e01bb99b552bdf2d7dbeaffected663c0c9496a69f80011205ba3194049bcafd681d to < 70ef2ba1f4286b2b73675aeb424b590c92d57b25affected663c0c9496a69f80011205ba3194049bcafd681d to < 4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0affected5ce93076d8ee2a0fac3ad4adbd2e91b6197146dbaffected5.3.6 to < 5.4affected
Linux Linux
Default version status: affected
5.4affected0 to < 5.4unaffected5.10.210 to ≤ 5.10.*unaffected5.15.149 to ≤ 5.15.*unaffected6.1.79 to ≤ 6.1.*unaffected6.6.18 to ≤ 6.6.*unaffected6.7.6 to ≤ 6.7.*unaffected6.8 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/230e89b5ad0a33f530a2a976b3e5e4385cb27882 ↗
- https://git.kernel.org/stable/c/2738e0aa2fb24a7ab9c878d912dc2b239738c6c6 ↗
- https://git.kernel.org/stable/c/0c09912dd8387e228afcc5e34ac5d79b1e3a1058 ↗
- https://git.kernel.org/stable/c/0516c06b19dc64807c10e01bb99b552bdf2d7dbe ↗
- https://git.kernel.org/stable/c/70ef2ba1f4286b2b73675aeb424b590c92d57b25 ↗
- https://git.kernel.org/stable/c/4a7aee96200ad281a5cc4cf5c7a2e2a49d2b97b0 ↗
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html ↗