Packages
- linux - Linux kernel
- linux-aws - Linux kernel for Amazon Web Services (AWS) systems
- linux-gke-5.3 - Linux kernel for Google Container Engine (GKE) systems
- linux-hwe - Linux hardware enablement (HWE) kernel
- linux-kvm - Linux kernel for cloud environments
- linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
- linux-oem-5.6 - Linux kernel for OEM systems
- linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
- linux-raspi2-5.3 - Linux kernel for Raspberry Pi (V8) systems
- linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors
Details
USN-4916-1 fixed vulnerabilities in the Linux kernel. Unfortunately,
the fix for CVE-2021-3493 introduced a memory leak in some situations.
This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges. (CVE-2021-3493)
Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)
USN-4916-1 fixed vulnerabilities in the Linux kernel. Unfortunately,
the fix for CVE-2021-3493 introduced a memory leak in some situations.
This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges. (CVE-2021-3493)
Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)
Update instructions
After a standard system update you need to reboot your computer to make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
Reduce your security exposure
Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.
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