diff options
| author | Michael Niedermayer <michael@niedermayer.cc> | 2022-12-21 00:31:00 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2023-05-26 00:04:32 +0200 |
| commit | cae611f86407ed7001437f59792f6ea18d3064da (patch) | |
| tree | 09ee1ad0a5ac1f6a26eb36a1c8158f4f643ca3ca | |
| parent | 662c3060b98467b1063172e79432e9a321339aa4 (diff) | |
| download | ffmpeg-cae611f86407ed7001437f59792f6ea18d3064da.tar.gz | |
avcodec/sunrast: Fix maplength check
Fixes: out of bounds read
Found-by: Ibrahim Mohamed <ielsayed@meta.com>
Reviewed-by; Ibrahim Mohamed <ielsayed@meta.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit f8a2a65078eaac37eae4a0d7ef440849a9d8f5b5)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/sunrast.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/libavcodec/sunrast.c b/libavcodec/sunrast.c index e1ec8a0832..991915fa62 100644 --- a/libavcodec/sunrast.c +++ b/libavcodec/sunrast.c @@ -19,6 +19,7 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "libavutil/avassert.h" #include "libavutil/common.h" #include "libavutil/intreadwrite.h" #include "libavutil/imgutils.h" @@ -75,6 +76,12 @@ static int sunrast_decode_frame(AVCodecContext *avctx, void *data, return AVERROR_PATCHWELCOME; } + if (maplength > 768) { + av_log(avctx, AV_LOG_WARNING, "invalid colormap length\n"); + return AVERROR_INVALIDDATA; + } + + // This also checks depth to be valid switch (depth) { case 1: avctx->pix_fmt = maplength ? AV_PIX_FMT_PAL8 : AV_PIX_FMT_MONOWHITE; @@ -96,15 +103,23 @@ static int sunrast_decode_frame(AVCodecContext *avctx, void *data, return AVERROR_INVALIDDATA; } + // This checks w and h to be valid in the sense that bytes of a padded bitmap are addressable with 32bit int ret = ff_set_dimensions(avctx, w, h); if (ret < 0) return ret; + // ensured by ff_set_dimensions() + av_assert0(w <= (INT32_MAX - 7) / depth); + /* scanlines are aligned on 16 bit boundaries */ len = (depth * w + 7) >> 3; alen = len + (len & 1); - if (buf_end - buf < maplength + (len * h) * 3 / 256) + // ensured by ff_set_dimensions() + av_assert0(h <= INT32_MAX / (3 * len)); + + // maplength is limited to 768 and the right term is limited to INT32_MAX / 256 so the add needs no check + if (buf_end - buf < (uint64_t)maplength + (len * h) * 3 / 256) return AVERROR_INVALIDDATA; if ((ret = ff_get_buffer(avctx, p, 0)) < 0) @@ -118,7 +133,7 @@ static int sunrast_decode_frame(AVCodecContext *avctx, void *data, } else if (maplength) { unsigned int len = maplength / 3; - if (maplength % 3 || maplength > 768) { + if (maplength % 3) { av_log(avctx, AV_LOG_WARNING, "invalid colormap length\n"); return AVERROR_INVALIDDATA; } |