FAILED: patch "[PATCH] drm/panthor: harden firmware build-info bounds checks" 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 8321b093fa6c297b80586460ce6914d9655df170
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090938-backlog-baton-1bbc@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From 8321b093fa6c297b80586460ce6914d9655df170 Mon Sep 17 00:00:00 2001
From: Osama Abdelkader <[email protected]>
Date: Mon, 20 Jul 2026 13:32:11 +0200
Subject: [PATCH] drm/panthor: harden firmware build-info bounds checks

panthor_fw_read_build_info() checks whether the metadata range fits in the firmware image with hdr.meta_start + hdr.meta_size. Both fields are u32, so the addition can wrap and let an out-of-bounds range pass validation.

The function also reads the "git_sha: " prefix without first checking that the metadata is long enough, and meta_size == 0 can underflow the NULL terminator index.

Use subtraction-based bounds checking and reject metadata that is too short to contain the expected prefix and trailing NULL byte.

index de8e6689a869..6a6f014d63e8 100644
@@ -697,7 +697,8 @@ static int panthor_fw_read_build_info(struct panthor_device *ptdev,
 		return ret;
 
 	if (hdr.meta_start > fw->size ||
-	    hdr.meta_start + hdr.meta_size > fw->size) {
+	    hdr.meta_size > fw->size - hdr.meta_start ||
+	    hdr.meta_size <= header_len) {
 		drm_err(&ptdev->base, "Firmware build info corrupt\n");
 		/* We don't need the build info, so continue */
 		return 0;