| Message ID | 20201031141626.727000-1-andreas.rheinhardt@gmail.com |
|---|---|
| State | Accepted |
| Commit | 2cf1eefae5dba7a7259156f9ff5c62f4e4e2fe0d |
| Headers | show |
| Series | [FFmpeg-devel,v3,1/4] avformat/apngdec: Return error for incomplete header | expand |
| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | success | Make fate finished |
On Sat, Oct 31, 2020 at 03:16:23PM +0100, Andreas Rheinhardt wrote: > If avio_read() could read anything, it returns the number of bytes read, > even if it could not read as much as the caller desired. > apng_read_header() only checked the return value of its avio_read() calls > for being negative and this meant that it was possible for an incomplete > header to not be detected. The return value of the last successfull call > has been returned instead. This commit changes this. > > Fixes: OOM > Fixes: 26608/clusterfuzz-testcase-minimized-ffmpeg_dem_APNG_fuzzer-4839491644424192 > > Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> > --- > libavformat/apngdec.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) I would have left the fix for the OOM and the 9 byte read seperate but the patch LGTM, please apply thx [...]
diff --git a/libavformat/apngdec.c b/libavformat/apngdec.c index 0f1d04a365..23d7e15393 100644 --- a/libavformat/apngdec.c +++ b/libavformat/apngdec.c @@ -138,7 +138,7 @@ static int append_extradata(AVCodecParameters *par, AVIOContext *pb, int len) par->extradata = new_extradata; par->extradata_size = new_size; - if ((ret = avio_read(pb, par->extradata + previous_size, len)) < 0) + if ((ret = ffio_read_size(pb, par->extradata + previous_size, len)) < 0) return ret; return previous_size; @@ -185,10 +185,10 @@ static int apng_read_header(AVFormatContext *s) AV_WL32(st->codecpar->extradata+4, tag); AV_WB32(st->codecpar->extradata+8, st->codecpar->width); AV_WB32(st->codecpar->extradata+12, st->codecpar->height); - if ((ret = avio_read(pb, st->codecpar->extradata+16, 9)) < 0) - goto fail; + if ((ret = ffio_read_size(pb, st->codecpar->extradata + 16, 9)) < 0) + return ret; - while (!avio_feof(pb)) { + while (1) { if (acTL_found && ctx->num_play != 1) { int64_t size = avio_size(pb); int64_t offset = avio_tell(pb);
If avio_read() could read anything, it returns the number of bytes read, even if it could not read as much as the caller desired. apng_read_header() only checked the return value of its avio_read() calls for being negative and this meant that it was possible for an incomplete header to not be detected. The return value of the last successfull call has been returned instead. This commit changes this. Fixes: OOM Fixes: 26608/clusterfuzz-testcase-minimized-ffmpeg_dem_APNG_fuzzer-4839491644424192 Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> --- libavformat/apngdec.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)