Red Hat Bugzilla – Bug 528887
CVE-2009-2909 kernel: ax25 stack overflow
Last modified: 2015-08-23 09:43:42 EDT
Description of problem:
Quote from this email:
fixed upstream in commit b7058842c940ad2c08dd829b21e5c92ebe3b8758 in a different way
The ax25 code tried to use
if (optlen < sizeof(int))
as a security check against optlen being negative (or zero) in the set socket option.
Unfortunately, "sizeof(int)" is an unsigned property, with the result that the whole comparison is done in unsigned, letting negative values slip through.
This patch changes this to
if (optlen < (int)sizeof(int))
so that the comparison is done as signed, and negative values get properly caught.
This issue did not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 4, 5, or Red Hat Enterprise MRG, as the affected driver is not enabled in these kernels.
The affected driver is available in Red Hat Enterprise Linux 3, but only if the kernel-unsupported package is installed.
Future kernel update in Red Hat Enterprise Linux 3 might address this flaw.
kernel-126.96.36.199-170.2.104.fc10 has been submitted as an update for Fedora 10.
kernel-188.8.131.52-170.2.104.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.
kernel-184.108.40.206-90.fc11 has been submitted as an update for Fedora 11.
kernel-220.127.116.11-90.fc11 has been pushed to the Fedora 11 stable repository. If problems still persist, please make note of it in this bug report.