#VU90355 Out-of-bounds read in Linux kernel - CVE-2021-46984

Vulnerability identifier: #VU90355

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-46984

CWE-ID: CWE-125

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

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

The vulnerability exists due to an out-of-bounds read error within the dd_request_merge() function in block/mq-deadline.c, within the kyber_limit_depth() function in block/kyber-iosched.c, within the __blk_mq_sched_bio_merge() function in block/blk-mq-sched.c, within the bfq_remove_request() function in block/bfq-iosched.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.9 rc1 - 6.9.3

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External links
https://git.kernel.org/stable/c/0b6b4b90b74c27bea968c214d820ba4254b903a5
https://git.kernel.org/stable/c/54dbe2d2c1fcabf650c7a8b747601da355cd7f9f
https://git.kernel.org/stable/c/a287cd84e047045f5a4d4da793414e848de627c6
https://git.kernel.org/stable/c/2ef3c76540c49167a0bc3d5f80d00fd1fc4586df
https://git.kernel.org/stable/c/efed9a3337e341bd0989161b97453b52567bc59d

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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.