From 056f59ad2cbfec4bfec9b401bc4f6b71f66302b2 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 28 Jun 2020 00:10:19 +0200 Subject: [PATCH] avcodec/wmalosslessdec: fix overflow with pred in revert_cdlms Fixes: signed integer overflow: 2048 + 2147483646 cannot be represented in type 'int' Fixes: 23538/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMALOSSLESS_fuzzer-5227567073460224 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 21598d711d894081d0566282473044ba4f378f33) Signed-off-by: Michael Niedermayer --- libavcodec/wmalosslessdec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c index bf555ce941..d10105d430 100644 --- a/libavcodec/wmalosslessdec.c +++ b/libavcodec/wmalosslessdec.c @@ -762,7 +762,8 @@ static void lms_update ## bits (WmallDecodeCtx *s, int ich, int ilms, int input) static void revert_cdlms ## bits (WmallDecodeCtx *s, int ch, \ int coef_begin, int coef_end) \ { \ - int icoef, pred, ilms, num_lms, residue, input; \ + int icoef, ilms, num_lms, residue, input; \ + unsigned pred;\ \ num_lms = s->cdlms_ttl[ch]; \ for (ilms = num_lms - 1; ilms >= 0; ilms--) { \ @@ -776,7 +777,7 @@ static void revert_cdlms ## bits (WmallDecodeCtx *s, int ch, \ s->cdlms[ch][ilms].recent, \ FFALIGN(s->cdlms[ch][ilms].order, ROUND), \ WMASIGN(residue)); \ - input = residue + (unsigned)(pred >> s->cdlms[ch][ilms].scaling); \ + input = residue + (unsigned)((int)pred >> s->cdlms[ch][ilms].scaling); \ lms_update ## bits(s, ch, ilms, input); \ s->channel_residues[ch][icoef] = input; \ } \