MGASA-2022-0101 - Updated kernel-linus packages fix security vulnerabilities

Publication date: 14 Mar 2022
URL: https://advisories.mageia.org/MGASA-2022-0101.html
Type: security
Affected Mageia releases: 8
CVE: CVE-2022-0001,
     CVE-2022-0002,
     CVE-2022-23036,
     CVE-2022-23037,
     CVE-2022-23038,
     CVE-2022-23039,
     CVE-2022-23040,
     CVE-2022-23041,
     CVE-2022-23042,
     CVE-2022-23960

This kernel-linus update is based on upstream 5.15.28 and fixes at least
the following security issues:

Non-transparent sharing of branch predictor selectors between contexts
in some Intel(R) Processors may allow an authorized user to potentially
enable information disclosure via local access (CVE-2022-0001).

Non-transparent sharing of branch predictor within a context in some
Intel(R) Processors may allow an authorized user to potentially enable
information disclosure via local access (CVE-2022-0002).

Several Linux PV device frontends are using the grant table interfaces
for removing access rights of the backends in ways being subject to
race conditions, resulting in potential data leaks, data corruption
by malicious backends, and denial of service triggered by malicious
backends:

blkfront, netfront, scsifront and the gntalloc driver are testing
whether a grant reference is still in use. If this is not the case,
they assume that a following removal of the granted access will always
succeed, which is not true in case the backend has mapped the granted
page between those two operations. As a result the backend can keep
access to the memory page of the guest no matter how the page will be
used after the frontend I/O has finished. The xenbus driver has a
similar problem, as it doesn't check the success of removing the
granted access of a shared ring buffer (blkfront: CVE-2022-23036,
netfront: CVE-2022-23037, scsifront: CVE-2022-23038,
gntalloc: CVE-2022-23039, xenbus: CVE-2022-23040)

blkfront, netfront, scsifront, usbfront, dmabuf, xenbus, 9p, kbdfront,
and pvcalls are using a functionality to delay freeing a grant reference
until it is no longer in use, but the freeing of the related data page
is not synchronized with dropping the granted access. As a result the
backend can keep access to the memory page even after it has been freed
and then re-used for a different purpose (CVE-2022-23041).

netfront will fail a BUG_ON() assertion if it fails to revoke access in
the rx path. This will result in a Denial of Service (DoS) situation of
the guest which can be triggered by the backend (CVE-2022-23042).

Certain Arm Cortex and Neoverse processors through 2022-03-08 do not
properly restrict cache speculation, aka Spectre-BHB. An attacker can
leverage the shared branch history in the Branch History Buffer (BHB)
to influence mispredicted branches. Then, cache allocation can allow
the attacker to obtain sensitive information (CVE-2022-23960).

It was found that the default LFENCE-based Spectre v2 mitigation on
AMD cpus is insufficient to mitigate such attacks. Becuse of that,
the code have been switched to use generic retpolines on AMD cpus
by default.

For other upstream fixes, see the referenced changelogs.

References:
- https://bugs.mageia.org/show_bug.cgi?id=30158
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00598.html
- https://developer.arm.com/Arm%20Security%20Center/Spectre-BHB
- https://seclists.org/oss-sec/2022/q1/173
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.27
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.28
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-0001
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-0002
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23036
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23037
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23038
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23039
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23040
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23041
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23042
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-23960

SRPMS:
- 8/core/kernel-linus-5.15.28-1.mga8