The CRAT parser validates that the subtype header fits within the image, but does not verify that the advertised subtype length fits. A malformed CRAT table with an oversized length field causes out-of-bounds reads when kfd_parse_subtype() casts the header to specific subtype structures.
Add validation that sub_type_hdr + length does not exceed the image boundary before parsing the subtype contents. Signed-off-by: William Palacek <[email protected]> --- drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c index 2a239f45fc24..6e0df685503d 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c @@ -1412,6 +1412,15 @@ int kfd_parse_crat_table(void *crat_image, struct list_head *device_list, break; } + /* Validate subtype fits within remaining image */ + if ((char *)sub_type_hdr + sub_type_hdr->length > + (char *)crat_image + image_len) { + pr_warn("CRAT subtype length %u exceeds image bounds\n", + sub_type_hdr->length); + ret = -EINVAL; + break; + } + if (sub_type_hdr->flags & CRAT_SUBTYPE_FLAGS_ENABLED) { ret = kfd_parse_subtype(sub_type_hdr, device_list); if (ret) -- 2.34.1
