| # HG changeset patch |
| # User Petr Písař <ppisar@redhat.com> |
| # Date 1560259692 25200 |
| # Tue Jun 11 06:28:12 2019 -0700 |
| # Branch SDL-1.2 |
| # Node ID f1f5878be5dbf63c1161a8ee52b8a86ece30e552 |
| # Parent a936f9bd3e381d67d8ddee8b9243f85799ea4798 |
| 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. |
| |
| 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> |
| |
| CVE: CVE-2019-7635 |
| Upstream-Status: Backport |
| Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> |
| |
| diff -r a936f9bd3e38 -r f1f5878be5db src/video/SDL_bmp.c |
| --- a/src/video/SDL_bmp.c Mon Jun 10 09:25:05 2019 -0700 |
| +++ b/src/video/SDL_bmp.c Tue Jun 11 06:28:12 2019 -0700 |
| @@ -308,6 +308,12 @@ |
| } |
| *(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; |
| |
| @@ -318,6 +324,16 @@ |
| 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. */ |