CVE-2023-1192: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-1192 is a use-after-free vulnerability discovered in the smb2isstatusiotimeout() function in CIFS (Common Internet File System) in the Linux Kernel. The vulnerability was identified when CIFS transfers response data to a system call, where local variables still point to a memory region that might be freed by the system call before CIFS can use it (Red Hat CVE, Ubuntu Security).

The vulnerability occurs in the CIFS kernel module's demultiplexing thread. After CIFS transfers response data to a system call, there are still local variable points to the memory region. If the system call frees the memory faster than CIFS can use it, CIFS will access a freed memory region when calling functions like smb2isstatusiotimeout(). The issue was fixed in the Linux kernel through commit d527f51331cace562393a8038d870b3e9916686f, which added an extra state to mark the mid state as READY before waking up the waiter (Kernel Commit).

The vulnerability can lead to a denial of service condition. However, the impact is considered low as it is not exploitable for more severe attacks. At worst, dereferencing an integer from the freed memory can trigger a spurious reconnect to the server, which may cause slight delays in system calls but should not disrupt application functionality (Red Hat Bugzilla).

The vulnerability has been patched in various Linux distributions through security updates. For Red Hat Enterprise Linux, the fix is available through multiple security advisories including RHSA-2023:7548, RHSA-2023:7549, and RHSA-2024:1250. Ubuntu has also released fixes for affected versions. Users should update their systems to the latest kernel versions that include these patches (Red Hat CVE).