The snd_seq_ioctl_remove_events function in sound/core/seq/seq_clientmgr.c in the Linux kernel before 4.4.1 does not verify FIFO assignment before proceeding with FIFO clearing, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) via a crafted ioctl call.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=030e2c78d3a91dd0d27fef37e91950dde333eba1
lists.opensuse.org/opensuse-security-announce/2016-03/msg00094.html
lists.opensuse.org/opensuse-security-announce/2016-04/msg00045.html
lists.opensuse.org/opensuse-security-announce/2016-08/msg00038.html
www.debian.org/security/2016/dsa-3503
www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.1
www.openwall.com/lists/oss-security/2016/01/19/1
www.securityfocus.com/bid/83377
www.securitytracker.com/id/1035304
www.ubuntu.com/usn/USN-2929-1
www.ubuntu.com/usn/USN-2929-2
www.ubuntu.com/usn/USN-2930-1
www.ubuntu.com/usn/USN-2930-2
www.ubuntu.com/usn/USN-2930-3
www.ubuntu.com/usn/USN-2931-1
www.ubuntu.com/usn/USN-2932-1
www.ubuntu.com/usn/USN-2967-1
www.ubuntu.com/usn/USN-2967-2
bugzilla.redhat.com/show_bug.cgi?id=1311554
github.com/torvalds/linux/commit/030e2c78d3a91dd0d27fef37e91950dde333eba1