Denial of service on Linux kernel

1) Infinite loop

EUVDB-ID: #VU48941

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25641

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect implementation of biovecs in Linux kernel. A zero-length biovec request issued by the block subsystem could cause the kernel to enter an infinite loop, causing a denial of service. A local user can issue requests to a block device and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.9 rc1 - 5.9 rc6

External links

http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html
http://www.openwall.com/lists/oss-security/2020/10/06/9
http://bugzilla.redhat.com/show_bug.cgi?id=1881424
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7e24969022cbd61ddc586f14824fc205661bb124
http://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
http://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
http://usn.ubuntu.com/4576-1/
http://www.kernel.org/doc/html/latest/block/biovecs.html

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.