CVE-2021-22600

A double-free flaw was found in the Linux kernel’s packet protocol subsystem in the way a user call triggers the packet_set_ring() function of the net/packet/af_packet.c. This flaw allows a local user to crash or escalate their privileges on the system.

The Red Hat Enterprise Linux versions before 9 are not affected, because the commit that introduced the bug is not in currently supported versions of Red Hat Enterprise Linux. The commit that introduced this bug is: 61fad6816fc1 ("net/packet: tpacket_rcv: avoid a producer race condition").

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.

Only users with access to the AF_PACKET socket can trigger this vulnerability. The mitigation would be to disable CAP_NET_RAW capability for the users that prevents access to AF_PACKET.