smb: Initialize cfid->tcon before performing network ops

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: smb: Initialize cfid->tcon before performing network ops Avoid leaking a tcon ref when a lease break races with opening the cached directory. Processing the leak break might take a reference to the tcon in cached_dir_lease_break() and then fail to release the ref in cached_dir_offload_close, since cfid->tcon is still NULL.

References

• https://git.kernel.org/stable/c/625e2357c8fcfae6e66dcc667dc656fe390bab15
• https://git.kernel.org/stable/c/4b216c8f9c7d84ef7de33ca60b97e08e03ef3292
• https://git.kernel.org/stable/c/1b9ab6b648f89441c8a13cb3fd8ca83ffebc5262
• https://git.kernel.org/stable/c/c353ee4fb119a2582d0e011f66a76a38f5cf984d