From f2b83f4aba2b9e248fb62cdfffb0842332b0e068 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 29 Dec 2017 03:00:19 +0100 Subject: [PATCH] avcodec/exr: Check buf_size more completely Fixes: Out of heap array read Fixes: 4683/clusterfuzz-testcase-minimized-6152313673613312 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 903be5e4f66268273dc6e3c42a7fdeaab32066ef) Signed-off-by: Michael Niedermayer --- libavcodec/exr.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/exr.c b/libavcodec/exr.c index b4063f8fa4..7fa17ca887 100644 --- a/libavcodec/exr.c +++ b/libavcodec/exr.c @@ -1062,7 +1062,7 @@ static int decode_block(AVCodecContext *avctx, void *tdata, line_offset = AV_RL64(s->gb.buffer + jobnr * 8); if (s->is_tile) { - if (line_offset > buf_size - 20) + if (buf_size < 20 || line_offset > buf_size - 20) return AVERROR_INVALIDDATA; src = buf + line_offset + 20; @@ -1073,7 +1073,7 @@ static int decode_block(AVCodecContext *avctx, void *tdata, tileLevelY = AV_RL32(src - 8); data_size = AV_RL32(src - 4); - if (data_size <= 0 || data_size > buf_size) + if (data_size <= 0 || data_size > buf_size - line_offset - 20) return AVERROR_INVALIDDATA; if (tileLevelX || tileLevelY) { /* tile level, is not the full res level */ @@ -1106,7 +1106,7 @@ static int decode_block(AVCodecContext *avctx, void *tdata, td->channel_line_size = td->xsize * s->current_channel_offset;/* uncompress size of one line */ uncompressed_size = td->channel_line_size * (uint64_t)td->ysize;/* uncompress size of the block */ } else { - if (line_offset > buf_size - 8) + if (buf_size < 8 || line_offset > buf_size - 8) return AVERROR_INVALIDDATA; src = buf + line_offset + 8; @@ -1116,7 +1116,7 @@ static int decode_block(AVCodecContext *avctx, void *tdata, return AVERROR_INVALIDDATA; data_size = AV_RL32(src - 4); - if (data_size <= 0 || data_size > buf_size) + if (data_size <= 0 || data_size > buf_size - line_offset - 8) return AVERROR_INVALIDDATA; td->ysize = FFMIN(s->scan_lines_per_block, s->ymax - line + 1); /* s->ydelta - line ?? */