An integer overflow can occur when processing any variant of a "literal run" in the lzo1x_decompress_safe function. Each of these three locations is subject to an integer overflow when processing zero bytes. This exposes the code that copies literals to memory corruption. An interesting side effect of the vulnerable code is that the value of 'op' can point to a region of memory just before the start of 'out'. It should be noted that on 64bit architectures, the overflow is still possible, but impractical. An overflow would require so much input data that an attack would obviously be infeasible even on modern computers. Upstream patch: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=206a81c18401c0cde6e579164f752c4b147324ce References: http://seclists.org/oss-sec/2014/q2/666 Acknowledgements: Red Hat would like to thank Don A. Bailey from Lab Mouse Security for reporting this issue.
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1113905]
Statement: This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5. Red Hat Enterprise Linux 7 and Red Hat Enterprise MRG 2 only support 64-bit architectures. Since exploiting this issue on 64-bit platforms is not feasible given the amount of input data that is necessary to trigger the integer overflow, we are currently not planning planning to fix this issue in Red Hat Enterprise Linux 7 and Red Hat Enterprise MRG 2.
kernel-3.14.9-200.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
Blog post and security report from the original reporter: http://blog.securitymouse.com/2014/06/raising-lazarus-20-year-old-bug-that.html https://www.securitymouse.com/lms-2014-06-16-2
kernel-3.14.13-100.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.
IssueDescription: An integer overflow flaw was found in the way the lzo1x_decompress_safe() function of the Linux kernel's LZO implementation processed Literal Runs. A local attacker could, in extremely rare cases, use this flaw to crash the system or, potentially, escalate their privileges on the system.
This issue has been addressed in the following products: Red Hat Enterprise Linux 6 Via RHSA-2014:1392 https://rhn.redhat.com/errata/RHSA-2014-1392.html
This issue has been addressed in the following products: Red Hat Enterprise Linux 6.5 EUS - Server and Compute Node Only Via RHSA-2015:0062 https://rhn.redhat.com/errata/RHSA-2015-0062.html