[v3.0] kernel: shmem: fix faulting into a hole while it's punched (CVE-2014-4171)
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.
Commit that fixes the issue is attached. Seems to be the same for kernels 3.6.y, 3.10.y, 3.14.y. Please see the parent issue for details.
(from redmine: issue id 3178, created on 2014-07-17, closed on 2017-05-17)
- parent #3174
- Revision 3a97f6f6 by Natanael Copa on 2014-07-24T16:55:06Z:
main/linux-grsec: upgrade to 3.14.13 grsecurity patch has fixes for various issues: CVE-2014-4943 CVE-2014-4171 fixes #3178 fixes #3217