Difference between revisions of "Bug Classes/Integer overflow"

From Linux Kernel Security Subsystem
Jump to navigation Jump to search
(→‎Examples: paste-o)
 
Line 8: Line 8:
* [https://cyseclabs.com/page?n=02012016 group_info refcount overflow]
* [https://cyseclabs.com/page?n=02012016 group_info refcount overflow]
* [http://perception-point.io/2016/01/14/analysis-and-exploitation-of-a-linux-kernel-vulnerability-cve-2016-0728/ keyring refcount overflow]
* [http://perception-point.io/2016/01/14/analysis-and-exploitation-of-a-linux-kernel-vulnerability-cve-2016-0728/ keyring refcount overflow]
* [https://code.google.com/p/google-security-research/issues/detail?id=758 netfilter xt_alloc_table_info integer overflow]


= Mitigations =
= Mitigations =

Latest revision as of 21:47, 9 March 2016

Details

Integer overflows (or underflows) occur when a multiplication happens that exceeds the size that can be represented by the datatype, generally wrapping around. This usually results in either writing to too-small buffers, or producing out of bound array indexes. Exploitation is most common via heap overflows, since the (too-small) buffers tend to be allocated on the heap. Additionally, reference counting can overflow and wrap around, leading to use-after-free exploits.

Examples

Mitigations

  • check for refcount overflows (e.g. PAX_REFCOUNT)
  • compiler instrumentation to detect multiplication overflows at runtime (e.g. PAX_SIZE_OVERFLOW)