Denial of service in Linux kernel f2fs

1) NULL pointer dereference

EUVDB-ID: #VU62483

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-2021-44879

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to a NULL pointer dereference error in the gc_data_segment() function in fs/f2fs/gc.c. A local user can mount a specially crafted f2fs image, trigger a NULL pointer dereference and perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: before 5.16.3

External links

http://bugzilla.kernel.org/show_bug.cgi?id=215231
http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.3
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9056d6489f5a41cfbb67f719d2c0ce61ead72d9f
http://lore.kernel.org/linux-f2fs-devel/20211206144421.3735-3-chao@kernel.org/T/

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.