From 34f6d1a7d7859310914d7f34e8cc3b68d6254003 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 1 Aug 2019 22:20:48 +0200 Subject: [PATCH] avcodec/pnm_parser: Use memmove() to handle "overread" This is significantly faster Fixes: Timeout (1sec after this and the previous commit) Fixes: 15558/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PPM_fuzzer-5705273643106304 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pnm_parser.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libavcodec/pnm_parser.c b/libavcodec/pnm_parser.c index 5339bebde9..94777d2cca 100644 --- a/libavcodec/pnm_parser.c +++ b/libavcodec/pnm_parser.c @@ -41,8 +41,11 @@ static int pnm_parse(AVCodecParserContext *s, AVCodecContext *avctx, int next = END_NOT_FOUND; int skip = 0; - for (; pc->overread > 0; pc->overread--) { - pc->buffer[pc->index++]= pc->buffer[pc->overread_index++]; + if (pc->overread > 0) { + memmove(pc->buffer + pc->index, pc->buffer + pc->overread_index, pc->overread); + pc->index += pc->overread; + pc->overread_index += pc->overread; + pc->overread = 0; } if (pnmpc->remaining_bytes) {