[USN-4997-1] Linux kernel vulnerabilities

========================================================================== Ubuntu Security Notice USN-4997-1 June 23, 2021
linux, linux-aws, linux-azure, linux-gcp, linux-oracle, linux-raspi vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 21.04
Summary:
Several security issues were fixed in the Linux kernel.
Software Description: – linux: Linux kernel – linux-aws: Linux kernel for Amazon Web Services (AWS) systems – linux-azure: Linux kernel for Microsoft Azure Cloud systems – linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems – linux-oracle: Linux kernel for Oracle Cloud systems – linux-raspi: Linux kernel for Raspberry Pi (V8) systems
Details:
Norbert Slusarek discovered a race condition in the CAN BCM networking protocol of the Linux kernel leading to multiple use-after-free vulnerabilities. A local attacker could use this issue to execute arbitrary code. (CVE-2021-3609)
Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly enforce limits for pointer operations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33200)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly clear received fragments from memory in some situations. A physically proximate attacker could possibly use this issue to inject packets or expose sensitive information. (CVE-2020-24586)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled encrypted fragments. A physically proximate attacker could possibly use this issue to decrypt fragments. (CVE-2020-24587)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled certain malformed frames. If a user were tricked into connecting to a malicious server, a physically proximate attacker could use this issue to inject packets. (CVE-2020-24588)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled EAPOL frames from unauthenticated senders. A physically proximate attacker could inject malicious packets to cause a denial of service (system crash). (CVE-2020-26139)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly verify certain fragmented frames. A physically proximate attacker could possibly use this issue to inject or decrypt packets. (CVE-2020-26141)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation accepted plaintext fragments in certain situations. A physically proximate attacker could use this issue to inject packets. (CVE-2020-26145)
Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation could reassemble mixed encrypted and plaintext fragments. A physically proximate attacker could possibly use this issue to inject packets or exfiltrate selected fragments. (CVE-2020-26147)
Or Cohen discovered that the SCTP implementation in the Linux kernel contained a race condition in some situations, leading to a use-after-free condition. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23133)
Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the nfc implementation in the Linux kernel. A privileged local attacker could use this issue to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23134)
Manfred Paul discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel contained an out-of-bounds vulnerability. A local attacker could use this issue to execute arbitrary code. (CVE-2021-31440)
Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly prevent speculative loads in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-31829)
It was discovered that a race condition in the kernel Bluetooth subsystem could lead to use-after-free of slab objects. An attacker could use this issue to possibly execute arbitrary code. (CVE-2021-32399)
It was discovered that a use-after-free existed in the Bluetooth HCI driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33034)
It was discovered that an out-of-bounds (OOB) memory access flaw existed in the f2fs module of the Linux kernel. A local attacker could use this issue to cause a denial of service (system crash). (CVE-2021-3506)
Mathias Krause discovered that a null pointer dereference existed in the Nitro Enclaves kernel driver of the Linux kernel. A local attacker could use this issue to cause a denial of service or possibly execute arbitrary code. (CVE-2021-3543)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 21.04:   linux-image-5.11.0-1009-azure   5.11.0-1009.9   linux-image-5.11.0-1010-oracle  5.11.0-1010.10   linux-image-5.11.0-1011-aws     5.11.0-1011.11   linux-image-5.11.0-1011-gcp     5.11.0-1011.12   linux-image-5.11.0-1012-raspi   5.11.0-1012.13   linux-image-5.11.0-1012-raspi-nolpae  5.11.0-1012.13   linux-image-5.11.0-22-generic   5.11.0-22.23   linux-image-5.11.0-22-generic-64k  5.11.0-22.23   linux-image-5.11.0-22-generic-lpae  5.11.0-22.23   linux-image-5.11.0-22-lowlatency  5.11.0-22.23   linux-image-aws                 5.11.0.1011.11   linux-image-azure               5.11.0.1009.9   linux-image-gcp                 5.11.0.1011.11   linux-image-generic             5.11.0.22.23   linux-image-generic-64k         5.11.0.22.23   linux-image-generic-lpae        5.11.0.22.23   linux-image-gke                 5.11.0.1011.11   linux-image-lowlatency          5.11.0.22.23   linux-image-oracle              5.11.0.1010.10   linux-image-raspi               5.11.0.1012.10   linux-image-raspi-nolpae        5.11.0.1012.10   linux-image-virtual             5.11.0.22.23
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-4997-1   CVE-2020-24586, CVE-2020-24587, CVE-2020-24588, CVE-2020-26139,   CVE-2020-26141, CVE-2020-26145, CVE-2020-26147, CVE-2021-23133,   CVE-2021-23134, CVE-2021-31440, CVE-2021-31829, CVE-2021-32399,   CVE-2021-33034, CVE-2021-33200, CVE-2021-3506, CVE-2021-3543,   CVE-2021-3609
Package Information:   launchpad.net/ubuntu/+source/linux/5.11.0-22.23   launchpad.net/ubuntu/+source/linux-aws/5.11.0-1011.11   launchpad.net/ubuntu/+source/linux-azure/5.11.0-1009.9   launchpad.net/ubuntu/+source/linux-gcp/5.11.0-1011.12   launchpad.net/ubuntu/+source/linux-oracle/5.11.0-1010.10   launchpad.net/ubuntu/+source/linux-raspi/5.11.0-1012.13