Do as Greg sayss [1][2]:
> All users of the 4.9 kernel series must upgrade.
Changes for Linux 4.9.11 [3][4]:
> Greg Kroah-Hartman announced the availability of two new Linux kernel
> releases, the Linux 4.4.50 LTS and Linux 4.9.11 LTS, both bringing
> various networking improvements and updated drivers.
>
> These new maintenance updates of the long-term supported Linux 4.9 and
> 4.4 kernel series are here only three days after the release of the
> Linux 4.4.49 LTS and Linux 4.9.10 LTS versions, so you can imagine that
> the changes implemented in point releases aren't so big. According to
> the appended shortlogs, Linux kernel 4.9.11 LTS changes a total of 49
> files, with 468 insertions and 342 deletions, and Linux kernel 4.4.50
> LTS comes with 29 files changed, with 172 insertions and 89 deletions.
>
> "I'm announcing the release of the 4.9.11 [and 4.4.50] kernel. All users
> of the 4.9 [and 4.4] kernel series must upgrade. The updated 4.9.y git
> tree can be found at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> linux-4.9.y and the updated 4.4.y git tree can be found at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> linux-4.4.y, and
> http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary,"
> said Greg Kroah-Hartman.
>
> ### There are mostly networking improvements with some updated drivers ###
>
> Both Linux 4.9.11 LTS and Linux 4.4.50 LTS kernels include an updated
> networking stack that adds various IPv4 and IPv6 improvements, as well
> as some small changes to things like Layer 2 Tunneling Protocol (L2TP),
> Distributed Switch Architecture (DSA), Datagram Congestion Control
> Protocol (DCCP), Controller Area Network (CAN), Ethernet, Stream Control
> Transmission Protocol (SCTP), and packet scheduler. On the other hand,
> they bring a few updated Ethernet drivers, for Mellanox and
> STMicroelectronics adapters.
>
> Those of you who are using GNU/Linux distributions powered by kernels
> from either the long-term supported Linux 4.9 or Linux 4.4 branches are
> urged to update their systems as soon as possible, or as soon as the new
> versions arrive in the stable repositories. OS vendors and power users
> can download the Linux kernel 4.4.50 LTS and Linux kernel 4.9.11 LTS
> source tarballs right now from kernel.org or via our website if they
> want to compile them themselves.
Changes for Linux 4.9.12 [5][6]:
> Greg Kroah-Hartman announced today the general availability of two new
> maintenance updates for the long-term supported Linux 4.9 and Linux 4.4
> kernels for Linux-based operating systems.
>
> Linux kernels 4.9.12 LTS and 4.4.51 LTS are now the latest stable and
> most advanced versions of the respective branches, and they are
> recommended to all users who run GNU/Linux distributions powered by
> either the Linux 4.4 or Linux 4.9 kernel series. These new point
> releases arrive only five days after the launch of their previous
> builds, namely Linux kernel 4.9.11 LTS and 4.4.50 LTS.
>
> "I'm announcing the release of the 4.9.12 [and 4.4.51] kernel. All users
> of the 4.9 [and 4.4] kernel series must upgrade. The updated 4.9.y git
> tree can be found at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> linux-4.9.y and 4.4.y git tree at
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> linux-4.4.y," said Greg Kroah-Hartman.
>
> ### The changes are small and include mostly updated drivers ###
>
> The changes included in today's Linux 4.9.12 and 4.4.51 LTS kernels are
> small and include mostly updated drivers that add various improvements
> to AMD Radeon GPUs, I2C, MD, media, MMC, NTB, PCI, and SCSI devices. A
> couple of bug fixes are implemented for ARM and PowerPC (PPC) hardware
> architectures, as well as the FUSE file system.
>
> According to the appended shortlog, 27 files were changed in Linux
> kernel 4.9.12, with 112 insertions and 92 deletions, and Linux kernel
> 4.4.51 LTS changes a total of 19 files, with 62 insertions and 45
> deletions. If you're using a GNU/Linux distro powered by a kernel from
> either the Linux 4.9 or 4.4 kernel series, it is recommended to update
> as soon as possible to these new versions, which you can also download
> right now from kernel.org or via our website.
[1] https://lkml.org/lkml/2017/2/18/90
[2] https://lkml.org/lkml/2017/2/23/381
[3] http://news.softpedia.com/news/linux-kernels-4-9-11-4-4-50-lts-bring-networking-improvements-updated-drivers-513073.shtml
[4] https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.11
[5] http://news.softpedia.com/news/linux-kernels-4-9-12-4-4-51-now-available-with-small-changes-updated-drivers-513246.shtml
[6] https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.12