Difference between revisions of "Exploit Methods/Userspace data usage"
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| Line 8: | Line 8: | ||
= Mitigations = | = 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: | |||
{| class="wikitable" | |||
!colspan="2"|CPU | |||
! Feature Name | |||
|- | |||
|rowspan="5"| ARM | |||
| v7 32-bit non-LPAE | |||
| CONFIG_CPU_SW_DOMAIN_PAN | |||
|- | |||
| v7 32-bit LPAE | |||
| [http://marc.info/?l=linux-arm-kernel&m=144308911409429&w=2 Catalin's series] (CONFIG_CPU_TTBR0_PAN) | |||
|- | |||
| v8 32-bit | |||
| Catalin's series? | |||
|- | |||
| v8 64-bit | |||
|style="color: red;"| nothing? | |||
|- | |||
| v8.1 | |||
| hardware PAN | |||
|- | |||
|rowspan="2"| x86 | |||
| pre-late-Broadwell | |||
|style="color: red;"| nothing | |||
|- | |||
| Broadwell+ | |||
| hardware PAN (SMAP) | |||
|- | |||
|colspan="2"| powerpc | |||
|style="color: red;"| nothing? | |||
|- | |||
|colspan="2"| MIPS | |||
|style="color: red;"| nothing? | |||
|} | |||
Revision as of 18:38, 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 | Catalin's series (CONFIG_CPU_TTBR0_PAN) | |
| v8 32-bit | Catalin's series? | |
| v8 64-bit | nothing? | |
| v8.1 | hardware PAN | |
| x86 | pre-late-Broadwell | nothing |
| Broadwell+ | hardware PAN (SMAP) | |
| powerpc | nothing? | |
| MIPS | nothing? | |