Exploit Methods/Userspace data usage

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(Mitigations)
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|-
 
|-
 
| v7 32-bit LPAE
 
| v7 32-bit LPAE
| [http://marc.info/?l=linux-arm-kernel&m=144308911409429&w=2 Catalin's series] (CONFIG_CPU_TTBR0_PAN)
+
| CONFIG_CPU_TTBR0_PAN ([http://marc.info/?l=linux-arm-kernel&m=144308911409429&w=2 Catalin's series])
 
|-
 
|-
 
| v8 32-bit
 
| v8 32-bit
| Catalin's series?
+
| CONFIG_CPU_TTBR0_PAN
 
|-
 
|-
 
| v8 64-bit
 
| v8 64-bit
|style="color: red;"| nothing?
+
|style="color: red;"| nothing
 
|-
 
|-
 
| v8.1
 
| v8.1

Revision as of 18:45, 10 December 2015

Details

Sometimes an attacker won't be able to control the instruction pointer directly, but they will be able to redirect the dereference a structure or other pointer. In these cases, it is easiest to aim at malicious structures that have been built in userspace to perform the exploitation.

Examples

Mitigations

  • hardware segmentation: SMAP (x86), PAN (arm, arm64), Domains (arm)
  • emulate memory segmentation via separate page tables, PCID, etc (e.g. PaX_UDEREF)

Right now, the upstream options available for PAN are:

CPU Feature Name
ARM v7 32-bit non-LPAE CONFIG_CPU_SW_DOMAIN_PAN
v7 32-bit LPAE CONFIG_CPU_TTBR0_PAN (Catalin's series)
v8 32-bit CONFIG_CPU_TTBR0_PAN
v8 64-bit nothing
v8.1 hardware PAN
x86 pre-late-Broadwell nothing
Broadwell+ hardware PAN (SMAP)
powerpc nothing?
MIPS nothing?
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