CVE-2024-49864

A flaw was found in the Linux kernel's rxrpc module. A race condition exists during the setup of a socket and its associated I/O thread. A remote attacker could send a specially crafted User Datagram Protocol (UDP) packet, which might be processed by rxrpc_encap_rcv() before the I/O thread is fully initialized. This could lead to a kernel 'oops', resulting in a system crash and a denial of service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the rxrpc kernel module from loading. This can be achieved by creating a modprobe configuration file.

Create a file named /etc/modprobe.d/blacklist-rxrpc.conf with the following content:

blacklist rxrpc

After creating the file, regenerate the initramfs to ensure the blacklist is applied during boot:

drancut --force
# Or for older systems:
mkinitrd -f /boot/initramfs-$(uname -r).img $(uname -r)

A system reboot is required for the changes to take effect. This mitigation may impact functionality that relies on the rxrpc protocol, such as AFS.