CVE-2022-4744: Double Free
A double-free flaw was found in the Linux kernel’s TUN/TAP device driver functionality in how a user registers the device when the registernetdevice function fails (NETDEVREGISTER notifier). This flaw allows a local user to crash or potentially escalate their privileges on the system.
Other sources
A flaw in the Linux Kernel found. If patch 158b515f703e ("tun: avoid double free in tunfreenetdev") not applied, then user can call registernetdevice() to fail that can lead to double free. One way to make a NETDEVREGISTER notifier fail is to create a device with name "default" or "all", which will be vetoed by devinetsysctlregister() because sysctldevnameisallowed() detects that the name is a reserved entry name in /proc/sys/net/ipv4/conf/.
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=158b515f703e
— Red Hat
Linux Kernel could allow a local authenticated attacker to gain elevated privileges on the system, caused by a double-free flaw in the TUN/TAP device driver functionality. An attacker could exploit this vulnerability to gain elevated privileges.
— IBM
Affected Software
Remediation
Information
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2022-4744?
CVE-2022-4744 is categorized as a high severity vulnerability due to its potential to allow privilege escalation.
How do I fix CVE-2022-4744?
To fix CVE-2022-4744, you should update your Linux kernel to one of the remedied versions listed by Red Hat, such as 0:5.14.0-162.22.2.el9_1 or higher.
Who is affected by CVE-2022-4744?
CVE-2022-4744 affects Linux kernels and certain IBM Security Verify Governance versions, making users of these systems potentially vulnerable.
What kind of attack can CVE-2022-4744 enable?
CVE-2022-4744 can enable a local user to crash the system or escalate their privileges.
Is CVE-2022-4744 specific to certain Linux distributions?
Yes, CVE-2022-4744 primarily affects Red Hat-based distributions, including those using the kernel and kernel-rt packages.