From bb263cc33afbab9520f776c03bc846ad316c7e18 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 22 Aug 2013 01:07:32 +0200 Subject: [PATCH] avcodec/rpza: Perform pointer advance and checks before using the pointers Fixes out of array accesses Fixes Ticket2850 Signed-off-by: Michael Niedermayer (cherry picked from commit 3819db745da2ac7fb3faacb116788c32f4753f34) Signed-off-by: Michael Niedermayer --- libavcodec/rpza.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/rpza.c b/libavcodec/rpza.c index a424759953..246d575ee4 100644 --- a/libavcodec/rpza.c +++ b/libavcodec/rpza.c @@ -84,7 +84,7 @@ static void rpza_decode_stream(RpzaContext *s) unsigned short *pixels = (unsigned short *)s->frame.data[0]; int row_ptr = 0; - int pixel_ptr = 0; + int pixel_ptr = -4; int block_ptr; int pixel_x, pixel_y; int total_blocks; @@ -140,6 +140,7 @@ static void rpza_decode_stream(RpzaContext *s) colorA = AV_RB16 (&s->buf[stream_ptr]); stream_ptr += 2; while (n_blocks--) { + ADVANCE_BLOCK() block_ptr = row_ptr + pixel_ptr; for (pixel_y = 0; pixel_y < 4; pixel_y++) { for (pixel_x = 0; pixel_x < 4; pixel_x++){ @@ -148,7 +149,6 @@ static void rpza_decode_stream(RpzaContext *s) } block_ptr += row_inc; } - ADVANCE_BLOCK(); } break; @@ -187,6 +187,7 @@ static void rpza_decode_stream(RpzaContext *s) if (s->size - stream_ptr < n_blocks * 4) return; while (n_blocks--) { + ADVANCE_BLOCK(); block_ptr = row_ptr + pixel_ptr; for (pixel_y = 0; pixel_y < 4; pixel_y++) { index = s->buf[stream_ptr++]; @@ -197,7 +198,6 @@ static void rpza_decode_stream(RpzaContext *s) } block_ptr += row_inc; } - ADVANCE_BLOCK(); } break; @@ -205,6 +205,7 @@ static void rpza_decode_stream(RpzaContext *s) case 0x00: if (s->size - stream_ptr < 16) return; + ADVANCE_BLOCK(); block_ptr = row_ptr + pixel_ptr; for (pixel_y = 0; pixel_y < 4; pixel_y++) { for (pixel_x = 0; pixel_x < 4; pixel_x++){ @@ -218,7 +219,6 @@ static void rpza_decode_stream(RpzaContext *s) } block_ptr += row_inc; } - ADVANCE_BLOCK(); break; /* Unknown opcode */