From 7ed8d5cfd94a53cca3599d40d2d9d2a8ee6f1bb8 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 15 Sep 2018 22:57:59 +0200 Subject: [PATCH] avcodec/pcx: Check for end of input in pcx_rle_decode() and propagate error Fixes: Timeout Fixes: 10279/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PCX_fuzzer-5729311395414016 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pcx.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/libavcodec/pcx.c b/libavcodec/pcx.c index 58a5e1e068..4505db75b8 100644 --- a/libavcodec/pcx.c +++ b/libavcodec/pcx.c @@ -30,7 +30,7 @@ #define PCX_HEADER_SIZE 128 -static void pcx_rle_decode(GetByteContext *gb, +static int pcx_rle_decode(GetByteContext *gb, uint8_t *dst, unsigned int bytes_per_scanline, int compressed) @@ -38,6 +38,9 @@ static void pcx_rle_decode(GetByteContext *gb, unsigned int i = 0; unsigned char run, value; + if (bytestream2_get_bytes_left(gb) < 1) + return AVERROR_INVALIDDATA; + if (compressed) { while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) { run = 1; @@ -52,6 +55,7 @@ static void pcx_rle_decode(GetByteContext *gb, } else { bytestream2_get_buffer(gb, dst, bytes_per_scanline); } + return 0; } static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen) @@ -153,7 +157,9 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, if (nplanes == 3 && bits_per_pixel == 8) { for (y = 0; y < h; y++) { - pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + if (ret < 0) + goto end; for (x = 0; x < w; x++) { ptr[3 * x] = scanline[x]; @@ -174,7 +180,9 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, } for (y = 0; y < h; y++, ptr += stride) { - pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + if (ret < 0) + goto end; memcpy(ptr, scanline, w); } @@ -194,7 +202,9 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, for (y = 0; y < h; y++) { init_get_bits8(&s, scanline, bytes_per_scanline); - pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + if (ret < 0) + goto end; for (x = 0; x < w; x++) ptr[x] = get_bits(&s, bits_per_pixel); @@ -204,7 +214,9 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, int i; for (y = 0; y < h; y++) { - pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); + if (ret < 0) + goto end; for (x = 0; x < w; x++) { int m = 0x80 >> (x & 7), v = 0;