The mountpoint_last function in fs/namei.c in the Linux kernel before 3.15.8 does not properly maintain a certain reference count during attempts to use the umount system call in conjunction with a symlink, which allows local users to cause a denial of service (memory consumption or use-after-free) or possibly have unspecified other impact via the umount program.
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
| Link | Tags |
|---|---|
| http://www.openwall.com/lists/oss-security/2014/07/24/2 | third party advisory mailing list |
| https://github.com/torvalds/linux/commit/295dc39d941dc2ae53d5c170365af4c9d5c16212 | exploit third party advisory patch |
| http://www.securityfocus.com/bid/68862 | vdb entry third party advisory |
| http://rhn.redhat.com/errata/RHSA-2015-0062.html | third party advisory vendor advisory |
| http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.15.8 | third party advisory patch vendor advisory |
| http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=295dc39d941dc2ae53d5c170365af4c9d5c16212 | |
| http://secunia.com/advisories/60353 | third party advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=1122472 | issue tracking third party advisory |