The collect_mounts function in fs/namespace.c in the Linux kernel before...

Vulnerability 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
• http://openwall.com/lists/oss-security/2015/05/29/5
• 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
• http://openwall.com/lists/oss-security/2015/05/29/10
• http://www.openwall.com/lists/oss-security/2015/06/04/5