From b1d9a808633f695aa74b5c8b59eb628bc1bea1e2 Mon Sep 17 00:00:00 2001 From: Alex Converse Date: Thu, 23 Feb 2012 10:47:50 -0800 Subject: [PATCH] tiff: Prevent overreads in the type_sizes array. Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC: libav-stable@libav.org (cherry picked from commit 447363870f2f91e125e07ac2d0820359a5d86b06) Signed-off-by: Anton Khirnov Signed-off-by: Reinhard Tartler --- libavcodec/tiff.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c index 6bfef220f4..71a4e70e3e 100644 --- a/libavcodec/tiff.c +++ b/libavcodec/tiff.c @@ -288,6 +288,11 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t * count = tget_long(&buf, s->le); off = tget_long(&buf, s->le); + if (type == 0 || type >= FF_ARRAY_ELEMS(type_sizes)) { + av_log(s->avctx, AV_LOG_DEBUG, "Unknown tiff type (%u) encountered\n", type); + return 0; + } + if(count == 1){ switch(type){ case TIFF_BYTE: @@ -309,10 +314,12 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t * value = -1; buf = start + off; } - }else if(type_sizes[type] * count <= 4){ - buf -= 4; - }else{ - buf = start + off; + } else { + if (count <= 4 && type_sizes[type] * count <= 4) { + buf -= 4; + } else { + buf = start + off; + } } if(buf && (buf < start || buf > end_buf)){