CVE-2023-54082: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54082 is a rejected/withdrawn CVE that was originally assigned to a use-after-free vulnerability in the Linux kernel's unix_stream_sendpage() function within the af_unix subsystem. The issue was reported by Bing-Jhong Billy Jheng and involved a race condition between unix_stream_sendpage() and the kernel's garbage collection for Unix domain sockets, potentially causing a null-pointer dereference and Denial of Service. The CVE was formally rejected by its CVE Numbering Authority, and its status is listed as "Rejected" (Red Hat Advisory, Red Hat Bugzilla). A CVSS v3.1 base score of 5.5 (Medium) was estimated prior to rejection, reflecting a local, low-privilege attack with high availability impact (Red Hat Bugzilla).

The underlying issue (CWE-416: Use-After-Free) resided in unix_stream_sendpage(), which attempted to append data to the last socket buffer (skb) in a peer's receive queue without holding the queue lock (Red Hat Bugzilla). A race condition could occur when a peer's file descriptor was passed in a loop between two Unix domain sockets: if both sockets were closed without receiving the FD, the kernel's garbage collector would unlink skbs under the queue lock, while unix_stream_sendpage() accessed the same skb locklessly, resulting in use-after-free. The fix, originally authored by Linus Torvalds, requires unix_stream_sendpage() to lock the peer's receive queue before access; the issue does not affect kernel 6.5+ due to prior sendpage() refactoring (Red Hat Bugzilla).

Successful exploitation of the underlying race condition could cause a kernel panic or null-pointer dereference, resulting in a Denial of Service (system crash) on affected Linux systems running kernels prior to 6.5 (Red Hat Bugzilla). There is no assessed impact to confidentiality or integrity based on the estimated CVSS vector. Exploitation requires local access with low privileges, limiting the attack surface primarily to multi-tenant or shared environments.

Because CVE-2023-54082 has been formally rejected, no official patch is tracked under this identifier. The underlying kernel bug was addressed upstream via a fix to unix_stream_sendpage() that enforces locking of the peer's receive queue; this fix is incorporated in Linux kernel 6.5 and later, which refactored sendpage() entirely (Red Hat Bugzilla). Users on kernels older than 6.5 should upgrade to a patched kernel version or apply vendor-supplied backport patches where available.

The upstream kernel security announcement was published via the Linux CVE announcement mailing list (Red Hat Bugzilla). Red Hat tracked the issue internally with low severity and priority, and the CVE was subsequently rejected by the CNA. No significant broader media coverage or notable researcher commentary beyond the initial bug report and upstream advisory has been identified.