From d02a49ba010515120a97afc7972ac954b98b51a4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 17 Jun 2024 22:43:22 +0200 Subject: [PATCH] avcodec/vc2enc: Fix overflows with storing large values Fixes: left shift of 1431634944 by 2 places cannot be represented in type 'int' Fixes: left shift of 1073741824 by 1 places cannot be represented in type 'int' Fixes: 69061/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC2_fuzzer-6325700826038272 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit af9935835335cae1ae5a4ec7fc14c1b5e25c1f2d) Signed-off-by: Michael Niedermayer --- libavcodec/vc2enc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libavcodec/vc2enc.c b/libavcodec/vc2enc.c index 6fbac29032..349174c8c7 100644 --- a/libavcodec/vc2enc.c +++ b/libavcodec/vc2enc.c @@ -185,7 +185,9 @@ typedef struct VC2EncContext { static av_always_inline void put_vc2_ue_uint(PutBitContext *pb, uint32_t val) { int i; - int pbits = 0, bits = 0, topbit = 1, maxval = 1; + int bits = 0; + unsigned topbit = 1, maxval = 1; + uint64_t pbits = 0; if (!val++) { put_bits(pb, 1, 1); @@ -202,12 +204,13 @@ static av_always_inline void put_vc2_ue_uint(PutBitContext *pb, uint32_t val) for (i = 0; i < bits; i++) { topbit >>= 1; + av_assert2(pbits <= UINT64_MAX>>3); pbits <<= 2; if (val & topbit) pbits |= 0x1; } - put_bits(pb, bits*2 + 1, (pbits << 1) | 1); + put_bits64(pb, bits*2 + 1, (pbits << 1) | 1); } static av_always_inline int count_vc2_ue_uint(uint32_t val)