Several security issues were fixed in the Linux kernel.
It was discovered that an integer overflow existed in the Linux kernel when reference counting pages, leading to potential use-after-free issues. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11487)
23 July 2019
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in the Linux kernel.
It was discovered that an integer overflow existed in the Linux kernel when reference counting pages, leading to potential use-after-free issues. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11487)
Jann Horn discovered that a race condition existed in the Linux kernel when performing core dumps. A local attacker could use this to cause a denial of service (system crash) or expose sensitive information. (CVE-2019-11599)
It was discovered that the ext4 file system implementation in the Linux kernel did not properly zero out memory in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2019-11833)
It was discovered that the Bluetooth Human Interface Device Protocol (HIDP) implementation in the Linux kernel did not properly verify strings were NULL terminated in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2019-11884)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.