Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets
When calling netlbl_conn_setattr(), addr->sa_family is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipso_sock_setattr() is triggered. Inside this function, the following code is executed:
sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL;
Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference.
This patch fixes the issue by checking if inet6_sk(sk) returns a NULL pointer before accessing pinet6.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+8 more)
In the Linux kernel, the following vulnerability has been resolved:
netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 sockets
When calling netlbl_conn_setattr(), addr->sa_family is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipso_sock_setattr() is triggered. Inside this function, the following code is executed:
sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL;
Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference.
This patch fixes the issue by checking if inet6_sk(sk) returns a NULL pointer before accessing pinet6.