The patch below does not apply to the 5.5-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 stable@vger.kernel.org.

thanks,

greg k-h

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

From 051c89cf4ac487e795d87e6f3b9e0ff788da8fb4 Mon Sep 17 00:00:00 2001

From: Chris Wilson chris@chris-wilson.co.uk Date: Thu, 23 Jan 2020 12:59:34 +0000 Subject: [PATCH] drm/i915/gem: Detect overflow in calculating dumb buffer size MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

To multiply 2 u32 numbers to generate a u64 in C requires a bit of forewarning for the compiler.

Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Ramalingam C ramalingam.c@intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@vger.kernel.org Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20200123125934.1401755-1-chris... (cherry picked from commit 0f8f8a64300092852b9361cd835395ee71e6a7d6) Signed-off-by: Jani Nikula jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 94f993e4c12f..c2de2f45b459 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -265,7 +265,10 @@ i915_gem_dumb_create(struct drm_file *file, DRM_FORMAT_MOD_LINEAR)) args->pitch = ALIGN(args->pitch, 4096);

- args->size = args->pitch * args->height; + if (args->pitch < args->width) + return -EINVAL; + + args->size = mul_u32_u32(args->pitch, args->height);

mem_type = INTEL_MEMORY_SYSTEM; if (HAS_LMEM(to_i915(dev)))