The SMB2_tcon function in fs/cifs/smb2pdu.c in the Linux kernel before 3.16.3 allows remote CIFS servers to cause a denial of service (NULL pointer dereference and client system crash) or possibly have unspecified other impact by deleting the IPC$ share during resolution of DFS referrals.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=18f39e7be0121317550d03e267e3ebd4dbfbb3ce
rhn.redhat.com/errata/RHSA-2015-0102.html
www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.16.3
www.openwall.com/lists/oss-security/2014/09/22/4
www.securityfocus.com/bid/69867
www.ubuntu.com/usn/USN-2394-1
github.com/torvalds/linux/commit/18f39e7be0121317550d03e267e3ebd4dbfbb3ce