NVIDIA Driver – Incorrect Bounds Check in Escape 0x70001b2

• Exploit Database
• 13 阅读

• 作者： Google Security Research
  日期： 2016-10-31
• 类别：

  • dos
  平台：

  • windows
• 来源：https://www.exploit-db.com/exploits/40664/

• Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=940
  
  The DxgkDdiEscape handler for 0x70001b2 doesn't do proper bounds checks for its
  variable size input.
  
  void sub_8C4304(...) {
  ...
  // escape_->size is controlled by the user.
  if ( escape_->size < size )
  size = escape_->size;
  memcpy(escape_->data, v31, 28i64 * size);
  ...
  }
  
  Note that this appears to be a common pattern. Normally, before
  escape handlers are executed, |PrivateDriverDataSize| (from DXGKARG_ESCAPE)
  is checked to be equal to some value against a hardcoded table. However, some escapes
  allow a more relaxed check that |PrivateDriverDataSize| >= minimum. This means that
  the handler themselves must implement an ad hoc bounds check, which either seems to be
  missing or implemented incorrectly (relying on a user specified value) in many cases.
  
  bug 936 is a similar issue and there are likely more. I've noticed (but not confirmed)
  a few more OOB reads that I haven't reported that follow this same pattern.
  
  Crashing context with PoC (Win 10 x64 with 372.54):
  
  PAGE_FAULT_IN_NONPAGED_AREA (50)
  Invalid system memory was referenced.This cannot be protected by try-except.
  Typically the address is just plain bad or it is pointing at freed memory.
  Arguments:
  ...
  rax=ffffd000239d51dc rbx=0000000000000000 rcx=fffffffffffffff4
  rdx=fffff000e9e6c754 rsi=0000000000000000 rdi=0000000000000000
  rip=fffff80166d6aca0 rsp=ffffd000239d3df8 rbp=ffffd000239d3f00
   r8=0000000000000924r9=000000000000003b r10=000000000000e9ef
  r11=ffffd000239d48ac r12=0000000000000000 r13=0000000000000000
  r14=0000000000000000 r15=0000000000000000
  iopl=0 nv up ei ng nz ac pe cy
  nvlddmkm+0x5daca0:
  fffff801`66d6aca0 f30f7f40f0movdquxmmword ptr [rax-10h],xmm0 ds:ffffd000`239d51cc=????????????????????????????????
  Resetting default scope
  
  To reproduce, compile as an x64 executable an run (requires WDK for D3DKMTEscape).
  
  
  Proof of Concept:
  https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40664.zip