Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tvrtko Ursulin , Chris Wilson , Rodrigo Vivi Subject: [PATCH 4.19 189/205] drm/i915: Large page offsets for pread/pwrite Date: Mon, 19 Nov 2018 17:28:16 +0100 Message-Id: <20181119162641.847991372@linuxfoundation.org> In-Reply-To: <20181119162616.586062722@linuxfoundation.org> References: <20181119162616.586062722@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit ab0d6a141843e0b4b2709dfd37b53468b5452c3a upstream. Handle integer overflow when computing the sub-page length for shmem backed pread/pwrite. Reported-by: Tvrtko Ursulin Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: stable@vger.kernel.org Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181012140228.29783-1-chris@chris-wilson.co.uk (cherry picked from commit a5e856a5348f6cd50889d125c40bbeec7328e466) Signed-off-by: Rodrigo Vivi Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1122,11 +1122,7 @@ i915_gem_shmem_pread(struct drm_i915_gem offset = offset_in_page(args->offset); for (idx = args->offset >> PAGE_SHIFT; remain; idx++) { struct page *page = i915_gem_object_get_page(obj, idx); - int length; - - length = remain; - if (offset + length > PAGE_SIZE) - length = PAGE_SIZE - offset; + unsigned int length = min_t(u64, remain, PAGE_SIZE - offset); ret = shmem_pread(page, offset, length, user_data, page_to_phys(page) & obj_do_bit17_swizzling, @@ -1570,11 +1566,7 @@ i915_gem_shmem_pwrite(struct drm_i915_ge offset = offset_in_page(args->offset); for (idx = args->offset >> PAGE_SHIFT; remain; idx++) { struct page *page = i915_gem_object_get_page(obj, idx); - int length; - - length = remain; - if (offset + length > PAGE_SIZE) - length = PAGE_SIZE - offset; + unsigned int length = min_t(u64, remain, PAGE_SIZE - offset); ret = shmem_pwrite(page, offset, length, user_data, page_to_phys(page) & obj_do_bit17_swizzling,