You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
2.3 KiB
69 lines
2.3 KiB
From 974b6b063b652317f1a2df12834c829415529bc5 Mon Sep 17 00:00:00 2001
|
|
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
|
|
Date: Tue, 11 Jun 2019 06:28:12 -0700
|
|
Subject: [PATCH 09/11] CVE-2019-7635: Reject BMP images with pixel colors out
|
|
the palette If a 1-, 4-, or 8-bit per pixel BMP image declares less used
|
|
colors than the palette offers an SDL_Surface with a palette of the indicated
|
|
number of used colors is created. If some of the image's pixel refer to a
|
|
color number higher then the maximal used colors, a subsequent bliting
|
|
operation on the surface will look up a color past a blit map (that is based
|
|
on the palette) memory. I.e. passing such SDL_Surface to e.g. an
|
|
SDL_DisplayFormat() function will result in a buffer overread in a blit
|
|
function.
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
This patch fixes it by validing each pixel's color to be less than the
|
|
maximal color number in the palette. A validation failure raises an
|
|
error from a SDL_LoadBMP_RW() function.
|
|
|
|
CVE-2019-7635
|
|
https://bugzilla.libsdl.org/show_bug.cgi?id=4498
|
|
|
|
Signed-off-by: Petr Písař <ppisar@redhat.com>
|
|
|
|
--HG--
|
|
branch : SDL-1.2
|
|
---
|
|
src/video/SDL_bmp.c | 16 ++++++++++++++++
|
|
1 file changed, 16 insertions(+)
|
|
|
|
diff --git a/src/video/SDL_bmp.c b/src/video/SDL_bmp.c
|
|
index d56cfd83a..8acae3bcb 100644
|
|
--- a/src/video/SDL_bmp.c
|
|
+++ b/src/video/SDL_bmp.c
|
|
@@ -296,6 +296,12 @@ SDL_Surface * SDL_LoadBMP_RW (SDL_RWops *src, int freesrc)
|
|
}
|
|
*(bits+i) = (pixel>>shift);
|
|
pixel <<= ExpandBMP;
|
|
+ if ( bits[i] >= biClrUsed ) {
|
|
+ SDL_SetError(
|
|
+ "A BMP image contains a pixel with a color out of the palette");
|
|
+ was_error = SDL_TRUE;
|
|
+ goto done;
|
|
+ }
|
|
} }
|
|
break;
|
|
|
|
@@ -306,6 +312,16 @@ SDL_Surface * SDL_LoadBMP_RW (SDL_RWops *src, int freesrc)
|
|
was_error = SDL_TRUE;
|
|
goto done;
|
|
}
|
|
+ if ( 8 == biBitCount && palette && biClrUsed < (1 << biBitCount ) ) {
|
|
+ for ( i=0; i<surface->w; ++i ) {
|
|
+ if ( bits[i] >= biClrUsed ) {
|
|
+ SDL_SetError(
|
|
+ "A BMP image contains a pixel with a color out of the palette");
|
|
+ was_error = SDL_TRUE;
|
|
+ goto done;
|
|
+ }
|
|
+ }
|
|
+ }
|
|
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
|
|
/* Byte-swap the pixels if needed. Note that the 24bpp
|
|
case has already been taken care of above. */
|
|
--
|
|
2.21.0
|
|
|