CVE-2023-0461

There is a use-after-free vulnerability in the Linux Kernel which can be exploited to achieve local privilege escalation. To reach the vulnerability kernel configuration flag CONFIG_TLS or CONFIG_XFRM_ESPINTCP has to be configured, but the operation does not require any privilege.

There is a use-after-free bug of icsk_ulp_data of a struct inet_connection_sock.

When CONFIG_TLS is enabled, user can install a tls context (struct tls_context) on a connected tcp socket. The context is not cleared if this socket is disconnected and reused as a listener. If a new socket is created from the listener, the context is inherited and vulnerable.

The setsockopt TCP_ULP operation does not require any privilege.

We recommend upgrading past commit 2c02d41d71f90a5168391b6a5f2954112ba2307c

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2c02d41d71f90a5168391b6a5f2954112ba2307c
• https://kernel.dance/#2c02d41d71f90a5168391b6a5f2954112ba2307c
• https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html
• https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2c02d41d71f90a5168391b6a5f2954112ba2307c
• https://kernel.dance/#2c02d41d71f90a5168391b6a5f2954112ba2307c
• https://lists.debian.org/debian-lts-announce/2023/05/msg00005.html
• https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
• https://security.netapp.com/advisory/ntap-20230331-0006/