From: Justin Green greenjustin@chromium.org

stable inclusion from -v4.19.316 commit 79078880795478d551a05acc41f957700030d364 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6S8E CVE: CVE-2024-38549

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 1e4350095e8ab2577ee05f8c3b044e661b5af9a0 ]

Add a check to mtk_drm_gem_init if we attempt to allocate a GEM object of 0 bytes. Currently, no such check exists and the kernel will panic if a userspace application attempts to allocate a 0x0 GBM buffer.

Tested by attempting to allocate a 0x0 GBM buffer on an MT8188 and verifying that we now return EINVAL.

Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.") Signed-off-by: Justin Green greenjustin@chromium.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Reviewed-by: CK Hu ck.hu@mediatek.com Link: https://patchwork.kernel.org/project/dri-devel/patch/20240307180051.4104425-... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Liu Chuang liuchuang40@huawei.com --- drivers/gpu/drm/mediatek/mtk_drm_gem.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c index b09a37a38e0a..079df67892df 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c @@ -26,6 +26,9 @@ static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,

size = round_up(size, PAGE_SIZE);

+ if (size == 0) + return ERR_PTR(-EINVAL); + mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL); if (!mtk_gem_obj) return ERR_PTR(-ENOMEM);