heap-buffer-overflow in IMG_LoadPCX_RW@IMG_pcx.c:178-24

[SDLBugzilla]

This bug report was migrated from our old Bugzilla tracker.

These attachments are available in the static archive:

• poc (heapoverflow.tar.gz, application/gzip, 2019-05-05 02:56:52 +0000, 296 bytes)

Reported in version: 2.0.4
Reported for operating system, platform: Linux, x86_64

Comments on the original bug report:

On 2019-05-05 02:56:52 +0000, pwd wrote:

Created attachment 3773
poc

IMG_LoadPCX_RW@IMG_pcx.c:178-24___heap-buffer-overflow

description

An issue was discovered in libsdl2 2.0.9 with SDL2_image-2.0.4, There is a heap-buffer-overflow in function IMG_LoadPCX_RW at IMG_pcx.c:178-24

commandline

loadtif  @@ 

source

 174                         }
 175                     } else
 176                         count = 1;
 177                 }
> 178                 dst[i] = ch;
 179                 count--;
 180             }
 181         }
 182 
 183         if(src_bits <= 4) {

// loadtif.c
// #include <stdio.h>
// #include <SDL.h>
// #include <SDL_image.h>
//
// int main(int argc, char * argv[]){
//         IMG_Init(IMG_INIT_TIF);//IMG_INIT_JPG);IMG_INIT_PNG
//         while(__AFL_LOOP(1000)){
//               SDL_Surface * image = IMG_Load(argv[1]);
//               if (image){
//                 SDL_FreeSurface(image);
//               }
//         }
//         IMG_Quit();
// }

bug report

=================================================================
==13979==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60200000eff4 at pc 0x7fcdecb76a15 bp 0x7ffddb89ab30 sp 0x7ffddb89ab28
WRITE of size 1 at 0x60200000eff4 thread T0
    # 0 0x7fcdecb76a14 in IMG_LoadPCX_RW /src/SDL2_image-2.0.4/IMG_pcx.c:178:24
    # 1 0x7fcdecb639bd in IMG_LoadTyped_RW /src/SDL2_image-2.0.4/IMG.c:195:17
    # 2 0x7fcdecb62f41 in IMG_Load /src/SDL2_image-2.0.4/IMG.c:136:12
    # 3 0x4ea0f0 in main /src/loadtif.c:8:37
    # 4 0x7fcdeb66982f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    # 5 0x4189e8 in _start (/src/aflbuild/installed/bin/loadtif+0x4189e8)

0x60200000eff4 is located 0 bytes to the right of 4-byte region [0x60200000eff0,0x60200000eff4)
allocated by thread T0 here:
    # 0 0x4b8b18 in malloc (/src/aflbuild/installed/bin/loadtif+0x4b8b18)
    # 1 0x7fcdec6de868 in SDL_malloc_REAL /src/libsdl2/src/stdlib/SDL_malloc.c:5328:11

SUMMARY: AddressSanitizer: heap-buffer-overflow /src/SDL2_image-2.0.4/IMG_pcx.c:178:24 in IMG_LoadPCX_RW
Shadow bytes around the buggy address:
  0x0c047fff9da0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9db0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dc0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9dd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9de0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fff9df0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa[04]fa
  0x0c047fff9e00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e30: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff9e40: 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
==13979==ABORTING

others

from fuzz project pwd-libsdl2-loadtif-00
crash name pwd-libsdl2-loadtif-00-00000000-20190418.tif
Auto-generated by pyspider at 2019-04-19 00:07:03

On 2019-06-10 22:21:50 +0000, Sam Lantinga wrote:

Fixed, thanks!
https://hg.libsdl.org/SDL_image/rev/7453e79c8cdb