tmpfs: clear S_ISGID when setting posix ACLs

Gu Zheng · Al Viro · commit 497de07d89c1 · 2017-01-10T01:29:48.000-05:00
This change was missed the tmpfs modification in In CVE-2016-7097 commit 0739310 ("posix_acl: Clear SGID bit when setting file permissions") It can test by xfstest generic/375, which failed to clear setgid bit in the following test case on tmpfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Signed-off-by: Gu Zheng <guzheng1@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
@@ -922,11 +922,10 @@ int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	int error;
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_equiv_mode(acl, &inode->i_mode);
-		if (error < 0)
-			return 0;
-		if (error == 0)
-			acl = NULL;
+		error = posix_acl_update_mode(inode,
+				&inode->i_mode, &acl);
+		if (error)
+			return error;
 	}
 
 	inode->i_ctime = current_time(inode);
