ksmbd: fix posix_acls and acls dereferencing possible ERR_PTR()

[ Upstream commit 25933573ef48f3586f559c2cac6c436c62dcf63f ]

Dan reported the following error message:

fs/smb/server/smbacl.c:1296 smb_check_perm_dacl()
    error: 'posix_acls' dereferencing possible ERR_PTR()
fs/smb/server/vfs.c:1323 ksmbd_vfs_make_xattr_posix_acl()
    error: 'posix_acls' dereferencing possible ERR_PTR()
fs/smb/server/vfs.c:1830 ksmbd_vfs_inherit_posix_acl()
    error: 'acls' dereferencing possible ERR_PTR()

__get_acl() returns a mix of error pointers and NULL. This change it
with IS_ERR_OR_NULL().

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c
index c24df86eb112be58c2ef4d73a1c87f201151bd65..8c041e71cf156ee310e8f3e1ddaaf2abd115b098 100644 (file)
--- a/fs/smb/server/smbacl.c
+++ b/fs/smb/server/smbacl.c
@@ -1313,7 +1313,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
 
        if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
                posix_acls = get_acl(d_inode(path->dentry), ACL_TYPE_ACCESS);
-               if (posix_acls && !found) {
+               if (!IS_ERR_OR_NULL(posix_acls) && !found) {
                        unsigned int id = -1;
 
                        pa_entry = posix_acls->a_entries;
@@ -1337,7 +1337,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
                                }
                        }
                }
-               if (posix_acls)
+               if (!IS_ERR_OR_NULL(posix_acls))
                        posix_acl_release(posix_acls);
        }
 

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index ebcd5a312f10dee3af7342372608e78de4bf3a3e..6d171f2757f15111de1f2f913751352158b135d2 100644 (file)
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -1322,7 +1322,7 @@ static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct user_namespac
                return NULL;
 
        posix_acls = get_acl(inode, acl_type);
-       if (!posix_acls)
+       if (IS_ERR_OR_NULL(posix_acls))
                return NULL;
 
        smb_acl = kzalloc(sizeof(struct xattr_smb_acl) +
@@ -1830,7 +1830,7 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
                return -EOPNOTSUPP;
 
        acls = get_acl(parent_inode, ACL_TYPE_DEFAULT);
-       if (!acls)
+       if (IS_ERR_OR_NULL(acls))
                return -ENOENT;
        pace = acls->a_entries;