Memory leak in Linux kernel btrfs

1) Memory leak

EUVDB-ID: #VU90436

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-2021-47508

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

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

The vulnerability exists due to memory leak within the btrfs_check_data_free_space() and btrfs_delalloc_reserve_space() functions in fs/btrfs/delalloc-space.c. A local user can perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.15 - 5.16 rc8

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:5.15:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc1:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc2:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc3:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc4:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc5:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc6:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15:rc7:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15.0:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:5.15.1:*:*:*:*:*:*:*

External links

https://git.kernel.org/stable/c/ca06c5cb1b6dbfe67655b33c02fc394d65824519
https://git.kernel.org/stable/c/da5e817d9d75422eaaa05490d0b9a5e328fc1a51
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.8
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16

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.