smb: client: fix possible double free in smb2_set_ea()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix possible double free in smb2_set_ea() Clang static checker(scan-build) warning： fs/smb/client/smb2ops.c:1304:2: Attempt to free released memory. 1304 | kfree(ea); | ^~~~~~~~~ There is a double free in such case: 'ea is initialized to NULL' -> 'first successful memory allocation for ea' -> 'something failed, goto sea_exit' -> 'first memory release for ea' -> 'goto replay_again' -> 'second goto sea_exit before allocate memory for ea' -> 'second memory release for ea resulted in double free'. Re-initialie 'ea' to NULL near to the replay_again label, it can fix this double free problem.

References

• https://git.kernel.org/stable/c/b1813c220b76f60b1727984794377c4aa849d4c1
• https://git.kernel.org/stable/c/c9f758ecf2562dfdd4adf12c22921b5de8366123
• https://git.kernel.org/stable/c/19ebc1e6cab334a8193398d4152deb76019b5d34