[USN-5015-1] Linux kernel (OEM) vulnerabilities

========================================================================== Ubuntu Security Notice USN-5015-1 July 20, 2021
linux-oem-5.10 vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux-oem-5.10: Linux kernel for OEM systems
Details:
It was discovered that the virtual file system implementation in the Linux kernel contained an unsigned to signed integer conversion error. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-33909)
Michael Brown discovered that the Xen netback driver in the Linux kernel did not properly handle malformed packets from a network PV frontend, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-28691)
It was discovered that the bluetooth subsystem in the Linux kernel did not properly handle HCI device initialization failure, leading to a double-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3564)
It was discovered that the bluetooth subsystem in the Linux kernel did not properly handle HCI device detach events, leading to a use-after-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3573)
It was discovered that the NFC implementation in the Linux kernel did not properly handle failed connect events leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service. (CVE-2021-3587)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04 LTS: linux-image-5.10.0-1038-oem 5.10.0-1038.40 linux-image-oem-20.04 5.10.0.1038.40 linux-image-oem-20.04b 5.10.0.1038.40
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.
References: ubuntu.com/security/notices/USN-5015-1 CVE-2021-28691, CVE-2021-33909, CVE-2021-3564, CVE-2021-3573, CVE-2021-3587
Package Information: launchpad.net/ubuntu/+source/linux-oem-5.10/5.10.0-1038.40