[PATCH 5.15.y 2/4] smb: client: refactor ACL setting control flow in id_mode_to_cifs_acl()

[Sasha Levin <sashal@kernel.org>]

From: Ralph Boehme <slow@samba.org>

[ Upstream commit a540a64c4801fe02e452ee37e961018106418260 ]

Refactor the control flow in id_mode_to_cifs_acl() to reduce nesting and
prevent error code overwriting.

Instead of wrapping the call to ops->set_acl() in a conditional block,
introduce early exits (goto id_mode_to_cifs_acl_exit) when build_sec_desc()
fails or ops->set_acl is NULL. This ensures that any actual error returned
by build_sec_desc() is not overwritten with -EOPNOTSUPP.

Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: d05045177a85 ("smb: client: fail DACL rewrite when the new DACL exceeds 64K")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/cifsacl.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index bb6aaf518f425..4e7ac1c4e5af0 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1770,14 +1770,18 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 
 	cifs_dbg(NOISY, "build_sec_desc rc: %d\n", rc);
 
-	if (ops->set_acl == NULL)
-		rc = -EOPNOTSUPP;
+	if (rc != 0)
+		goto id_mode_to_cifs_acl_exit;
 
-	if (!rc) {
-		/* Set the security descriptor */
-		rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag);
-		cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
+	if (ops->set_acl == NULL) {
+		rc = -EOPNOTSUPP;
+		goto id_mode_to_cifs_acl_exit;
 	}
+
+	/* Set the security descriptor */
+	rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag);
+	cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
+
 id_mode_to_cifs_acl_exit:
 	cifs_put_tlink(tlink);
 
-- 
2.53.0