FAILED: patch "[PATCH] drm/amdkfd: Add bounds check for CRAT subtype length" failed to apply to 6.12-stable tree

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 6e7566ba4739dd573c331adde1c96690f7a567bd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026080546-bloomers-primary-c22d@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6e7566ba4739dd573c331adde1c96690f7a567bd Mon Sep 17 00:00:00 2001
From: William Palacek <[email protected]>
Date: Mon, 6 Jul 2026 10:25:58 -0400
Subject: [PATCH] drm/amdkfd: Add bounds check for CRAT subtype length

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.

index 2a239f45fc24..6e0df685503d 100644
@@ -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)