Use-after-free in Linux kernel

1) Use-after-free

EUVDB-ID: #VU30292

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-10690

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

There is a use-after-free in kernel versions before 5.5 due to a race condition between the release of ptp_clock and cdev while resource deallocation. When a (high privileged) process allocates a ptp device file (like /dev/ptpX) and voluntarily goes to sleep. During this time if the underlying device is removed, it can cause an exploitable condition as the process wakes up to terminate and clean all attached files. The system crashes due to the cdev structure being invalid (as already freed) which is pointed to by the inode.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.0 - 5.4.42

External links

http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10690
http://lists.debian.org/debian-lts-announce/2020/06/msg00011.html
http://lists.debian.org/debian-lts-announce/2020/06/msg00013.html
http://security.netapp.com/advisory/ntap-20200608-0001/

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.