From 35005a4af1ebe1ec1b5724121a03036705417fc7 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Fri, 29 Nov 2019 20:44:09 +0100 Subject: [PATCH] avformat/flac_picture: Simplify checks During parsing a flac picture metadata block, the mimetype is read as follows: Its 32b size field is read and checked for being in the range 1..63; afterwards, the actual mimetype-string is read into a buffer of size 64, where the length to read is the minimum of the length field and the size of the destination buffer -1. Then an assert guards that length is indeed < the size of the destination buffer before the string in the buffer is zero-terminated. The FFMIN as well as the assert are actually redundant, as it has been checked that the string (even after terminating) fits into the buffer. In order to make this clear, reword the check "len >= 64" to "len >= sizeof(mimetype)" and drop the FFMIN as well as the assert. Signed-off-by: Andreas Rheinhardt Signed-off-by: Michael Niedermayer --- libavformat/flac_picture.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/libavformat/flac_picture.c b/libavformat/flac_picture.c index f0871d9c79..6463a370c8 100644 --- a/libavformat/flac_picture.c +++ b/libavformat/flac_picture.c @@ -19,7 +19,6 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -#include "libavutil/avassert.h" #include "libavutil/intreadwrite.h" #include "libavcodec/png.h" #include "avformat.h" @@ -54,15 +53,14 @@ int ff_flac_parse_picture(AVFormatContext *s, uint8_t *buf, int buf_size) /* picture mimetype */ len = avio_rb32(pb); - if (len <= 0 || len >= 64 || - avio_read(pb, mimetype, FFMIN(len, sizeof(mimetype) - 1)) != len) { + if (len <= 0 || len >= sizeof(mimetype) || + avio_read(pb, mimetype, len) != len) { av_log(s, AV_LOG_ERROR, "Could not read mimetype from an attached " "picture.\n"); if (s->error_recognition & AV_EF_EXPLODE) ret = AVERROR_INVALIDDATA; goto fail; } - av_assert0(len < sizeof(mimetype)); mimetype[len] = 0; while (mime->id != AV_CODEC_ID_NONE) {