The sanity_check_raw_super function in fs/f2fs/super.c in the Linux kernel before 4.11.1 does not validate the segment count, which allows local users to gain privileges via unspecified vectors.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b9dd46188edc2f0d1f37328637860bb65a771124
www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.11.1
www.securityfocus.com/bid/100215
bugzilla.redhat.com/show_bug.cgi?id=1481146
github.com/torvalds/linux/commit/b9dd46188edc2f0d1f37328637860bb65a771124
source.android.com/security/bulletin/2017-08-01