USN-4367-2: Linux kernel regression
Publication date
28 May 2020
Overview
USN-4367-1 introduced a regression in the Linux kernel.
Releases
Packages
- linux - Linux kernel
Details
USN-4367-1 fixed vulnerabilities in the 5.4 Linux kernel. Unfortunately,
that update introduced a regression in overlayfs. This update corrects
the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that the btrfs implementation in the Linux kernel did not
properly detect that a block was marked dirty in some situations. An
attacker could use this to specially craft a file system image that, when
unmounted, could cause a denial of service (system crash). (CVE-2019-19377)
It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)
It was discovered that the block layer in the Linux kernel...
USN-4367-1 fixed vulnerabilities in the 5.4 Linux kernel. Unfortunately,
that update introduced a regression in overlayfs. This update corrects
the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that the btrfs implementation in the Linux kernel did not
properly detect that a block was marked dirty in some situations. An
attacker could use this to specially craft a file system image that, when
unmounted, could cause a denial of service (system crash). (CVE-2019-19377)
It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)
It was discovered that the block layer in the Linux kernel contained a race
condition leading to a use-after-free vulnerability. A local attacker could
possibly use this to cause a denial of service (system crash) or execute
arbitrary code. (CVE-2020-12657)
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:
Ubuntu Release | Package Version | ||
---|---|---|---|
20.04 focal | linux-image-5.4.0-33-generic – 5.4.0-33.37 | ||
linux-image-5.4.0-33-generic-lpae – 5.4.0-33.37 | |||
linux-image-5.4.0-33-lowlatency – 5.4.0-33.37 | |||
linux-image-generic – 5.4.0.33.38 | |||
linux-image-generic-lpae – 5.4.0.33.38 | |||
linux-image-lowlatency – 5.4.0.33.38 | |||
linux-image-oem – 5.4.0.33.38 | |||
linux-image-oem-osp1 – 5.4.0.33.38 | |||
linux-image-virtual – 5.4.0.33.38 |
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