cifs: check whether acl is valid early

Dan reported that acl is dereferenced before being checked and this is a
valid problem. Fix it be erroring out early instead of doing it later after
we've already relied on acl to be a valid pointer.

Fixes: dc1af4c4b4 ("cifs: implement set acl method")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2022-10-28 12:45:10 +02:00 committed by Christian Brauner (Microsoft)
parent a351b1f444
commit cb2144d66b
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2

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@ -1764,6 +1764,10 @@ int cifs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
rc = PTR_ERR(full_path);
goto out;
}
if (!acl)
goto out;
/* return dos attributes as pseudo xattr */
/* return alt name if available as pseudo attr */
@ -1778,8 +1782,6 @@ int cifs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
switch (type) {
case ACL_TYPE_ACCESS:
if (!acl)
goto out;
if (sb->s_flags & SB_POSIXACL)
rc = cifs_do_set_acl(xid, pTcon, full_path, acl,
ACL_TYPE_ACCESS,
@ -1788,8 +1790,6 @@ int cifs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
break;
case ACL_TYPE_DEFAULT:
if (!acl)
goto out;
if (sb->s_flags & SB_POSIXACL)
rc = cifs_do_set_acl(xid, pTcon, full_path, acl,
ACL_TYPE_DEFAULT,