CVE-2021-4028

A flaw in the Linux kernels implementation of RDMA communications manager listener code allowed an attacker with local access to setup a socket to listen on a high port allowing for a list element to be used after free. Given the ability to execute code, a local attacker could leverage this use-after-free to crash the system or possibly escalate privileges on the system.

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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://access.redhat.com/security/cve/CVE-2021-4028
• https://bugzilla.redhat.com/show_bug.cgi?id=2027201
• https://bugzilla.suse.com/show_bug.cgi?id=1193167#c0
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bc0bdc5afaa74
• https://lkml.org/lkml/2021/10/4/697
• https://security.netapp.com/advisory/ntap-20221228-0002/
• https://access.redhat.com/security/cve/CVE-2021-4028
• https://bugzilla.redhat.com/show_bug.cgi?id=2027201
• https://bugzilla.suse.com/show_bug.cgi?id=1193167#c0
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bc0bdc5afaa74
• https://lkml.org/lkml/2021/10/4/697
• https://security.netapp.com/advisory/ntap-20221228-0002/