From d6fe3786cd8c06437756d407f727ff01cf1774ff Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 9 Aug 2025 11:38:07 +0200 Subject: [PATCH] avcodec/jpeg2000dec: Make sure the 4 extra bytes allocated are initialized Fixes: use of uninitialized memory Fixes: 429130590/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_DEC_fuzzer-5736930522497024 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/jpeg2000dec.c | 1 + 1 file changed, 1 insertion(+) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index 59f3133d1f..221ba87305 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -1532,6 +1532,7 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile, bytestream2_get_bufferu(&s->g, cblk->data + cblk->length, cblk->lengthinc[cwsno]); cblk->length += cblk->lengthinc[cwsno]; + memset(cblk->data + cblk->length, 0, 4); cblk->lengthinc[cwsno] = 0; if (cblk->nb_terminationsinc) { cblk->nb_terminationsinc--;