From efbcd312060a9598e7e63f0e8ca8515d8ce109ef Mon Sep 17 00:00:00 2001 From: James Almer Date: Thu, 5 Jun 2025 21:07:14 -0300 Subject: [PATCH] avcodec/ac3_parser: use a padded buffer in av_ac3_parse_header() The GetBitContext API requires the buffer to be padded, and the documentation for av_ac3_parse_header() does not specify it, so use a temporary local buffer. Signed-off-by: James Almer --- libavcodec/ac3_parser.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c index 69989690dd..1d9a40a8d9 100644 --- a/libavcodec/ac3_parser.c +++ b/libavcodec/ac3_parser.c @@ -202,9 +202,13 @@ int av_ac3_parse_header(const uint8_t *buf, size_t size, { GetBitContext gb; AC3HeaderInfo hdr; + uint8_t tmp[32 + AV_INPUT_BUFFER_PADDING_SIZE]; int err; - err = init_get_bits8(&gb, buf, size); + size = FFMIN(32, size); + memcpy(tmp, buf, size); + memset(tmp + size, 0, AV_INPUT_BUFFER_PADDING_SIZE); + err = init_get_bits8(&gb, tmp, size); if (err < 0) return AVERROR_INVALIDDATA; err = ff_ac3_parse_header(&gb, &hdr);