From bf2d7b20ea1c7d15dcbaedd479f40295e5c83430 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 15 Dec 2023 02:07:56 +0100 Subject: [PATCH] avcodec/jpegxl_parser: Add padding to cs_buffer Fixes: out of array access Fixes: 64081/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-6151006496620544 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 5f88458bea698e00913a38940a7c34994151d2a8) Signed-off-by: Michael Niedermayer --- libavcodec/jpegxl_parser.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libavcodec/jpegxl_parser.c b/libavcodec/jpegxl_parser.c index 4e4d27c3c8..ad1dc46271 100644 --- a/libavcodec/jpegxl_parser.c +++ b/libavcodec/jpegxl_parser.c @@ -162,7 +162,7 @@ typedef struct JXLParseContext { int skipped_icc; int next; - uint8_t cs_buffer[4096]; + uint8_t cs_buffer[4096 + AV_INPUT_BUFFER_PADDING_SIZE]; } JXLParseContext; /* used for reading brotli prefixes */ @@ -1400,7 +1400,7 @@ static int try_parse(AVCodecParserContext *s, AVCodecContext *avctx, JXLParseCon if (ctx->container || AV_RL64(buf) == FF_JPEGXL_CONTAINER_SIGNATURE_LE) { ctx->container = 1; ret = ff_jpegxl_collect_codestream_header(buf, buf_size, ctx->cs_buffer, - sizeof(ctx->cs_buffer), &ctx->copied); + sizeof(ctx->cs_buffer) - AV_INPUT_BUFFER_PADDING_SIZE, &ctx->copied); if (ret < 0) return ret; ctx->collected_size = ret; @@ -1409,7 +1409,7 @@ static int try_parse(AVCodecParserContext *s, AVCodecContext *avctx, JXLParseCon return AVERROR_BUFFER_TOO_SMALL; } cs_buffer = ctx->cs_buffer; - cs_buflen = FFMIN(sizeof(ctx->cs_buffer), ctx->copied); + cs_buflen = FFMIN(sizeof(ctx->cs_buffer) - AV_INPUT_BUFFER_PADDING_SIZE, ctx->copied); } else { cs_buffer = buf; cs_buflen = buf_size;