Memory leak in Linux kernel ksmbd

1) Memory leak

EUVDB-ID: #VU90439

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-2021-47568

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 get_file_stream_info() function in fs/ksmbd/smb2pdu.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/11e659827c3a2facb3a04e08cc97ff14d5091f51
https://git.kernel.org/stable/c/178ca6f85aa3231094467691f5ea1ff2f398aa8d
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.6
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.