NVIDIA Driver 375.70 - DxgkDdiEscape 0x100008b Out-of-Bounds Read/Write

EDB-ID:

41364




Platform:

Windows

Date:

2017-02-15


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Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=985

The DxgkDdiEscape handler for 0x100008b accepts a user supplied size as the                                                                                    
limit for a loop, leading to OOB reads and writes.

The supplied PoC passes an invalid size of 0x41414141, which causes a crash in:

__int64 sub_30A500(__int64 a1, __int64 a2, _DWORD *ptr, unsigned int user_supplied_size)
{
  __int64 i; // r11@2

  if ( user_supplied_size )
  {
    i = user_supplied_size;
    do
    {
      if ( *ptr == 3 || (unsigned int)(*ptr - 9) <= 1 )
        *ptr = 0;
      ptr += 3;
      --i;
    }
    while ( i );

Crashing context on Win 10 x64, driver version 375.70:

TRAP_FRAME:  ffffd000266219e0 -- (.trap 0xffffd000266219e0)
NOTE: The trap frame does not contain all registers.
Some register values may be zeroed or incorrect.
rax=00000000fffffff7 rbx=0000000000000000 rcx=ffffe000d6315000
rdx=ffffe000d691b000 rsi=0000000000000000 rdi=0000000000000000
rip=fffff8010e34a50b rsp=ffffd00026621b78 rbp=ffffe000d691b000
 r8=ffffd000266228a8  r9=0000000041414141 r10=ffffd00026623004
r11=00000000414140a4 r12=0000000000000000 r13=0000000000000000
r14=0000000000000000 r15=0000000000000000
iopl=0         nv up ei pl nz na pe nc
nvlddmkm+0x2fa50b:
fffff801`0e34a50b 418b02          mov     eax,dword ptr [r10] ds:ffffd000`26623004=????????


Proof of Concept:
https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/41364.zip