Race condition in Linux kernel block driver

1) Race condition

EUVDB-ID: #VU91489

Risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20261

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local privileged user to execute arbitrary code.

The vulnerability exists due to a race condition within the set_fdc(), do_format(), user_reset_fdc(), set_geometry(), get_floppy_geometry(), fd_locked_ioctl(), floppy_check_events() and floppy_revalidate() functions in drivers/block/floppy.c. A local privileged user can execute arbitrary code.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: All versions

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:*:*:*:*:*:*:*:*

External links

https://bugzilla.redhat.com/show_bug.cgi?id=1932150
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a0c80efe5956ccce9fe7ae5c78542578c07bc20a

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.