Origin: https://github.com/webmproject/libvpx/commit/9d7054c0cb83665a74cf6f59b6261f455e692149 Backport of: From 9d7054c0cb83665a74cf6f59b6261f455e692149 Mon Sep 17 00:00:00 2001 From: Wan-Teh Chang Date: Thu, 11 Apr 2024 10:24:11 -0700 Subject: [PATCH] Avoid integer overflows in arithmetic operations A port of the libaom CL https://aomedia-review.googlesource.com/c/aom/+/188823. Impose maximum values on the input parameters so that we can perform arithmetic operations without worrying about overflows. Also change the VpxImageTest.VpxImgAllocHugeWidth test to write to the first and last samples in the first row of the Y plane, so that the test will crash if there is unsigned integer overflow in the calculation of stride_in_bytes. Bug: chromium:332382766 Change-Id: I54cec6c9e26377abaa8a991042ba277ff70afdf3 (cherry picked from commit 06af417e795e6a9b9309406ba399fb109def89e6) --- test/vpx_image_test.cc | 19 +++++++++++++++++++ vpx/src/vpx_image.c | 11 +++++++++++ vpx/vpx_image.h | 16 +++++++++++----- 3 files changed, 41 insertions(+), 5 deletions(-) --- a/test/vpx_image_test.cc +++ b/test/vpx_image_test.cc @@ -8,6 +8,8 @@ * be found in the AUTHORS file in the root of the source tree. */ +#include + #include "vpx/vpx_image.h" #include "third_party/googletest/src/include/gtest/gtest.h" @@ -81,6 +83,10 @@ TEST(VpxImageTest, VpxImgAllocHugeWidth) image = vpx_img_alloc(nullptr, VPX_IMG_FMT_I420, 0x80000000, 1, 1); ASSERT_EQ(image, nullptr); + // The aligned width (UINT_MAX + 1) would overflow unsigned int. + image = vpx_img_alloc(nullptr, VPX_IMG_FMT_I420, UINT_MAX, 1, 1); + ASSERT_EQ(image, nullptr); + image = vpx_img_alloc(nullptr, VPX_IMG_FMT_I420, 0x7ffffffe, 1, 1); if (image) { vpx_img_free(image); @@ -101,8 +107,21 @@ TEST(VpxImageTest, VpxImgAllocHugeWidth) vpx_img_free(image); } + image = vpx_img_alloc(nullptr, VPX_IMG_FMT_I42016, 65536, 2, 1); + if (image) { + uint16_t *y_plane = + reinterpret_cast(image->planes[VPX_PLANE_Y]); + y_plane[0] = 0; + y_plane[image->d_w - 1] = 0; + vpx_img_free(image); + } + image = vpx_img_alloc(nullptr, VPX_IMG_FMT_I42016, 285245883, 2, 1); if (image) { + uint16_t *y_plane = + reinterpret_cast(image->planes[VPX_PLANE_Y]); + y_plane[0] = 0; + y_plane[image->d_w - 1] = 0; vpx_img_free(image); } } --- a/vpx/src/vpx_image.c +++ b/vpx/src/vpx_image.c @@ -8,6 +8,7 @@ * be found in the AUTHORS file in the root of the source tree. */ +#include #include #include #include @@ -28,6 +29,14 @@ static vpx_image_t *img_alloc_helper(vpx if (img != NULL) memset(img, 0, sizeof(vpx_image_t)); + /* Impose maximum values on input parameters so that this function can + * perform arithmetic operations without worrying about overflows. + */ + if (d_w > 0x08000000 || d_h > 0x08000000 || buf_align > 65536 || + stride_align > 65536) { + goto fail; + } + /* Treat align==0 like align==1 */ if (!buf_align) buf_align = 1; @@ -103,8 +112,10 @@ static vpx_image_t *img_alloc_helper(vpx /* Calculate storage sizes given the chroma subsampling */ align = (1 << xcs) - 1; w = (d_w + align) & ~align; + assert(d_w <= w); align = (1 << ycs) - 1; h = (d_h + align) & ~align; + assert(d_h <= h); s = (fmt & VPX_IMG_FMT_PLANAR) ? w : (uint64_t)bps * w / 8; s = (s + stride_align - 1) & ~((uint64_t)stride_align - 1); --- a/vpx/vpx_image.h +++ b/vpx/vpx_image.h @@ -132,10 +132,13 @@ typedef struct vpx_image_rect { * is NULL, the storage for the descriptor will be * allocated on the heap. * \param[in] fmt Format for the image - * \param[in] d_w Width of the image - * \param[in] d_h Height of the image + * \param[in] d_w Width of the image. Must not exceed 0x08000000 + * (2^27). + * \param[in] d_h Height of the image. Must not exceed 0x08000000 + * (2^27). * \param[in] align Alignment, in bytes, of the image buffer and - * each row in the image(stride). + * each row in the image (stride). Must not exceed + * 65536. * * \return Returns a pointer to the initialized image descriptor. If the img * parameter is non-null, the value of the img parameter will be @@ -155,9 +158,12 @@ vpx_image_t *vpx_img_alloc(vpx_image_t * * parameter is NULL, the storage for the descriptor * will be allocated on the heap. * \param[in] fmt Format for the image - * \param[in] d_w Width of the image - * \param[in] d_h Height of the image + * \param[in] d_w Width of the image. Must not exceed 0x08000000 + * (2^27). + * \param[in] d_h Height of the image. Must not exceed 0x08000000 + * (2^27). * \param[in] stride_align Alignment, in bytes, of each row in the image. + * Must not exceed 65536. * \param[in] img_data Storage to use for the image * * \return Returns a pointer to the initialized image descriptor. If the img