On 20/07/2026 12:32, Osama Abdelkader wrote:
> 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.
>
> Fixes: 2718d91816ee ("drm/panthor: Add the FW logical block")
> Cc: [email protected]
> Signed-off-by: Osama Abdelkader <[email protected]>
Reviewed-by: Steven Price <[email protected]>
I'll push this to drm-misc-fixes.
Thanks,
Steve
> ---
> drivers/gpu/drm/panthor/panthor_fw.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c
> b/drivers/gpu/drm/panthor/panthor_fw.c
> index 6335893d3f16..9d0e1fafdce2 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -709,7 +709,8 @@ 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;
