mm/shmem.c in the Linux kernel through 3.15.1 does not properly implement the interaction between range notification and hole punching, which allows local users to cause a denial of service (i_mutex hold) by using the mmap system call to access a hole, as demonstrated by interfering with intended shmem activity by blocking completion of (1) an MADV_REMOVE madvise call or (2) an FALLOC_FL_PUNCH_HOLE fallocate call.
http://lists.opensuse.org/opensuse-security-announce/2014-10/msg00006.html
http://lists.opensuse.org/opensuse-security-announce/2014-10/msg00007.html
http://marc.info/?l=linux-mm-commits&m=140303745420549&w=2
http://ozlabs.org/~akpm/mmots/broken-out/shmem-fix-faulting-into-a-hole-while-its-punched.patch
http://rhn.redhat.com/errata/RHSA-2014-1318.html
http://rhn.redhat.com/errata/RHSA-2015-0102.html
http://secunia.com/advisories/59777
http://secunia.com/advisories/60564
http://www.openwall.com/lists/oss-security/2014/06/18/11
http://www.securityfocus.com/bid/68157
http://www.securitytracker.com/id/1030450
http://www.ubuntu.com/usn/USN-2334-1
Source: MITRE
Published: 2014-06-23
Updated: 2018-12-18
Type: NVD-CWE-Other
Base Score: 4.7
Vector: AV:L/AC:M/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 3.4
Severity: MEDIUM