Description
The collect_mounts function in fs/namespace.c in the Linux kernel before 4.0.5 does not properly consider that it may execute after a path has been unmounted, which allows local users to cause a denial of service (system crash) by leveraging user-namespace root access for an MNT_DETACH umount2 system call.
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cd4a40174b71acd021877341684d8bb1dc8ea4ae
- [oss-security] 20150529 CVE request Linux kernel: ns: user namespaces panic mailing-list
- https://bugzilla.redhat.com/show_bug.cgi?id=1248486
- https://github.com/torvalds/linux/commit/cd4a40174b71acd021877341684d8bb1dc8ea4ae
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.0.5
- [oss-security] 20150529 Re: CVE request Linux kernel: ns: user namespaces panic mailing-list
- [oss-security] 20150604 Re: Re: CVE request Linux kernel: ns: user namespaces panic mailing-list