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Reported in version: HG 1.2 Reported for operating system, platform: Linux, x86_64
Comments on the original bug report:
On 2019-02-08 08:55:05 +0000, Radue wrote:
Created attachment 3606
PoC
A heap-buffer overflow vulnerability was discovered in SDL-1.2.15 library.
ASAN report:
=================================================================
==30184==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61900000e580 at pc 0x7f17151f9538 bp 0x7ffe8733fb30 sp 0x7ffe8733fb28
READ of size 1 at 0x61900000e580 thread T0
# 0 0x7f17151f9537 in Map1toN /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_pixels.c:482:3
# 1 0x7f17151f9537 in SDL_MapSurface /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_pixels.c:583
# 2 0x7f1715204deb in SDL_LowerBlit /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_surface.c:417:8
# 3 0x7f1715204deb in SDL_ConvertSurface /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_surface.c:866
# 4 0x7f171520aa40 in SDL_DisplayFormat /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_video.c:946:9
# 5 0x4dba11 in LoadSprite /home/radu/apps/sdl_player_lib/SDL-1.2.15/test/testsprite.c:41:9
# 6 0x4dbc8f in main /home/radu/apps/sdl_player_lib/SDL-1.2.15/test/testsprite.c:98:7
# 7 0x7f1713ede82f in __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/../csu/libc-start.c:291
# 8 0x435528 in _start (/home/radu/apps/sdl_player_lib/SDL-1.2.15/test/testsprite+0x435528)
0x61900000e580 is located 0 bytes to the right of 1024-byte region [0x61900000e180,0x61900000e580)
allocated by thread T0 here:
# 0 0x4bc4f2 in malloc (/home/radu/apps/sdl_player_lib/SDL-1.2.15/test/testsprite+0x4bc4f2)
# 1 0x7f17151f4ae8 in SDL_AllocFormat /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_pixels.c:133:44
SUMMARY: AddressSanitizer: heap-buffer-overflow /home/radu/apps/sdl_player_lib/SDL-1.2.15/build/../src/video/SDL_pixels.c:482 Map1toN
Shadow bytes around the buggy address:
0x0c327fff9c60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c327fff9c70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c327fff9c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c327fff9c90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c327fff9ca0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c327fff9cb0:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c327fff9cc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c327fff9cd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c327fff9ce0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c327fff9cf0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c327fff9d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==30184==ABORTING
Poc: See attachment
Reproducing steps:
Download SDL-1.2.15 library
./configure with Asan enabled
./make
sudo make install
cd examples
./configure with Asan enabled
modify testsprite.c to load the poc.bmp file
make
./testsprite PoC
On 2019-02-10 14:59:08 +0000, Radue wrote:
Assigned CVE-2019-7638 by MITRE.
On 2019-02-15 14:44:35 +0000, Petr Pisar wrote:
My valgrind output actually points to:
==29868== Invalid read of size 1
==29868== at 0x4882F41: Map1to1 (SDL_pixels.c:459)
==29868== by 0x48835AD: SDL_MapSurface (SDL_pixels.c:569)
==29868== by 0x4884978: SDL_LowerBlit (SDL_surface.c:417)
==29868== by 0x48859AA: SDL_ConvertSurface (SDL_surface.c:866)
==29868== by 0x4887EE3: SDL_DisplayFormat (SDL_video.c:946)
==29868== by 0x4013E2: LoadSprite (testsprite.c:49)
==29868== by 0x401B25: main (testsprite.c:224)
The issue is that src->colors[i] points to an invalid memory because src->ncolors is ridiculously large (131075) and is much larger than number of elements in src->colors[] array. The SDL_Pallete src comes unchanged from LoadSprite() in testsprite.c program:
int LoadSprite(char *file)
{
[...]
sprite = SDL_LoadBMP(file);
[...]
}
as sprite->format->palette:
(gdb) p sprite->format->palette->ncolors
$20 = 131075
(gdb) p sprite->format->palette->colors[131075-1]
Cannot access memory at address 0x4887f8
This I conclude that SDL_LoadBMP() misparses the crafted BMP file. It's not an issue in SDL video system at all.
On 2019-02-15 15:45:13 +0000, Petr Pisar wrote:
The reproducer has these data in BITMAPINFOHEADER:
biSize = 40
biBitCount = 8
biClrUsed = 131075
SDL_LoadBMP_RW() function passes biBitCount as a color depth to SDL_CreateRGBSurface(), thus 256-color pallete is allocated. But then biClrUsed colors are read from a file and stored into the palette. SDL_LoadBMP_RW should report an error if biClrUsed is greater than 2^biBitCount.
On 2019-02-15 16:10:08 +0000, Petr Pisar wrote:
Created attachment 3624
Fix
On 2019-02-18 13:59:05 +0000, Petr Pisar wrote:
Created attachment 3631
Fix
The fix also resolved CVE-2019-7636 reported in bug # 4499.
This bug report was migrated from our old Bugzilla tracker.
These attachments are available in the static archive:
Fix (0001-CVE-2019-7638-Refuse-loading-BMP-images-with-too-hig.patch, text/plain, 2019-02-15 16:10:08 +0000, 1708 bytes)Reported in version: HG 1.2
Reported for operating system, platform: Linux, x86_64
Comments on the original bug report:
On 2019-02-08 08:55:05 +0000, Radue wrote:
On 2019-02-10 14:59:08 +0000, Radue wrote:
On 2019-02-15 14:44:35 +0000, Petr Pisar wrote:
On 2019-02-15 15:45:13 +0000, Petr Pisar wrote:
On 2019-02-15 16:10:08 +0000, Petr Pisar wrote:
On 2019-02-18 13:59:05 +0000, Petr Pisar wrote:
On 2019-02-18 15:52:40 +0000, Sam Lantinga wrote:
The text was updated successfully, but these errors were encountered: