CVE-2023-54280 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix potential race when tree connecting ipc
Protect access of TCP_Server_Info::hostname when building the ipc tree name as it might get freed in cifsd thread and thus causing an use-after-free bug in __tree_connect_dfs_target(). Also, while at it, update status of IPC tcon on success and then avoid any extra tree connects.
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Analysis
by VulDB Data Team • 04/27/2026
The vulnerability CVE-2023-54280 resides within the Linux kernel's CIFS (Common Internet File System) implementation, specifically addressing a critical race condition during the tree connection process for IPC (Inter-Process Communication) shares. This flaw manifests when multiple threads attempt to access shared resources simultaneously, creating a scenario where the TCP_Server_Info::hostname field becomes accessible while it is concurrently being freed by a cifsd thread. The underlying issue stems from improper synchronization mechanisms during the construction of IPC tree names, which can lead to memory corruption and unpredictable system behavior.
The technical implementation of this vulnerability involves a use-after-free condition that occurs in the __tree_connect_dfs_target() function when processing DFS (Distributed File System) targets. When the kernel attempts to build an IPC tree name, it accesses the TCP_Server_Info::hostname field without adequate protection mechanisms, allowing a separate cifsd thread to free this memory location while another thread is still referencing it. This race condition creates a classic memory safety issue where the program attempts to use memory that has already been deallocated, potentially leading to arbitrary code execution or system crashes. The vulnerability is classified under CWE-416 as Use After Free, which represents a fundamental memory management flaw where program memory is accessed after it has been freed.
The operational impact of CVE-2023-54280 extends beyond simple system instability, as it can be exploited to achieve privilege escalation or denial of service conditions within environments heavily dependent on CIFS file sharing. Systems running Linux kernels with affected CIFS implementations are particularly vulnerable when handling concurrent connections to DFS targets, especially in enterprise environments where multiple processes might simultaneously attempt to establish IPC connections. The vulnerability affects the integrity of the kernel's memory management subsystem and can compromise the security posture of networked systems that rely on CIFS for file sharing operations, potentially allowing attackers to execute malicious code with kernel-level privileges or cause persistent service disruptions.
Mitigation strategies for this vulnerability primarily involve applying the kernel patch that implements proper locking mechanisms around the TCP_Server_Info::hostname field access during IPC tree name construction. The fix ensures that the hostname field remains accessible until the tree connection process is complete, preventing concurrent access patterns that lead to the use-after-free condition. Additionally, system administrators should implement proper kernel version management and regular patching procedures to maintain system security. The solution aligns with ATT&CK technique T1068 by addressing privilege escalation pathways through kernel memory corruption vulnerabilities, while also supporting the broader security principle of proper resource management and synchronization in concurrent programming environments. Organizations should prioritize updating their Linux systems to versions containing the fix, particularly those operating CIFS servers or clients in high-availability or security-sensitive environments where concurrent access patterns are common.