From: Jeremy Cline jcline@redhat.com
[ Upstream commit 8b335bff643f3b39935c7377dbcd361c5b605d98 ]
KASAN reported a slab-out-of-bounds read of size 1 in kdf_create_vcrat_image_cpu().
This occurs when, for example, when on an x86_64 with a single NUMA node because kfd_fill_iolink_info_for_cpu() is a no-op, but afterwards the sub_type_hdr->length, which is out-of-bounds, is read and multiplied by entries. Fortunately, entries is 0 in this case so the overall crat_table->length is still correct.
Check if there were any entries before de-referencing sub_type_hdr which may be pointing to out-of-bounds memory.
Fixes: b7b6c38529c9 ("drm/amdkfd: Calculate CPU VCRAT size dynamically (v2)") Suggested-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Jeremy Cline jcline@redhat.com Reviewed-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c index d7f67620f57ba..31d793ee0836e 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c @@ -1034,11 +1034,14 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size) (struct crat_subtype_iolink *)sub_type_hdr); if (ret < 0) return ret; - crat_table->length += (sub_type_hdr->length * entries); - crat_table->total_entries += entries;
- sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr + - sub_type_hdr->length * entries); + if (entries) { + crat_table->length += (sub_type_hdr->length * entries); + crat_table->total_entries += entries; + + sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr + + sub_type_hdr->length * entries); + } #else pr_info("IO link not available for non x86 platforms\n"); #endif