Am 2021-01-11 um 4:05 p.m. schrieb Jeremy Cline:
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
Thanks. I'll apply this patch.
Reviewed-by: Felix Kuehling Felix.Kuehling@amd.com
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 8cac497c2c45..a5640a6138cf 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c @@ -1040,11 +1040,14 @@ 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