cifs: smb2ops: Fix NULL check in smb2_query_symlink

The current code null checks variable err_buf, which is always null
when it is checked, hence utf16_path is free'd and the function
returns -ENOENT everytime it is called, making it impossible for the
execution path to reach the following code:

err_buf = err_iov.iov_base;

Fix this by null checking err_iov.iov_base instead of err_buf. Also,
notice that err_buf no longer needs to be initialized to NULL.

Addresses-Coverity-ID: 1467876 ("Logically dead code")
Fixes: 2d636199e400 ("cifs: Change SMB2_open to return an iov for the error parameter")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b4ae932ea13448aa31509142c72ec71a360eb967..38ebf3f357d29233571c2319fb45940f1cc1f5fe 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1452,7 +1452,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
        struct kvec err_iov = {NULL, 0};
-       struct smb2_err_rsp *err_buf = NULL;
+       struct smb2_err_rsp *err_buf;
        struct smb2_symlink_err_rsp *symlink;
        unsigned int sub_len;
        unsigned int sub_offset;
@@ -1476,7 +1476,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 
        rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov);
 
-       if (!rc || !err_buf) {
+       if (!rc || !err_iov.iov_base) {
                kfree(utf16_path);
                return -ENOENT;
        }