Amazon Linux 1 Security Advisory: ALAS-2014-417
Advisory Release Date: 2014-09-18 21:04 Pacific
Advisory Updated Date: 2014-09-19 12:11 Pacific
fs/namespace.c in the Linux kernel through 3.16.1 does not properly restrict clearing MNT_NODEV, MNT_NOSUID, and MNT_NOEXEC and changing MNT_ATIME_MASK during a remount of a bind mount, which allows local users to gain privileges, interfere with backups and auditing on systems that had atime enabled, or cause a denial of service (excessive filesystem updating) on systems that had atime disabled via a "mount -o remount" command within a user namespace.
The do_remount function in fs/namespace.c in the Linux kernel through 3.16.1 does not maintain the MNT_LOCK_READONLY bit across a remount of a bind mount, which allows local users to bypass an intended read-only restriction and defeat certain sandbox protection mechanisms via a "mount -o remount" command within a user namespace.
Affected Packages:
kernel
Issue Correction:
Run yum update kernel to update your system. You will need to reboot your system in order for the new kernel to be running.
i686:
kernel-tools-debuginfo-3.14.19-17.43.amzn1.i686
kernel-3.14.19-17.43.amzn1.i686
kernel-debuginfo-3.14.19-17.43.amzn1.i686
perf-3.14.19-17.43.amzn1.i686
kernel-tools-3.14.19-17.43.amzn1.i686
kernel-devel-3.14.19-17.43.amzn1.i686
kernel-tools-devel-3.14.19-17.43.amzn1.i686
perf-debuginfo-3.14.19-17.43.amzn1.i686
kernel-headers-3.14.19-17.43.amzn1.i686
kernel-debuginfo-common-i686-3.14.19-17.43.amzn1.i686
noarch:
kernel-doc-3.14.19-17.43.amzn1.noarch
src:
kernel-3.14.19-17.43.amzn1.src
x86_64:
perf-debuginfo-3.14.19-17.43.amzn1.x86_64
kernel-devel-3.14.19-17.43.amzn1.x86_64
perf-3.14.19-17.43.amzn1.x86_64
kernel-3.14.19-17.43.amzn1.x86_64
kernel-debuginfo-3.14.19-17.43.amzn1.x86_64
kernel-tools-devel-3.14.19-17.43.amzn1.x86_64
kernel-debuginfo-common-x86_64-3.14.19-17.43.amzn1.x86_64
kernel-tools-3.14.19-17.43.amzn1.x86_64
kernel-tools-debuginfo-3.14.19-17.43.amzn1.x86_64
kernel-headers-3.14.19-17.43.amzn1.x86_64