From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 19 Sep 2020 16:55:58 +0000 (+0100)
Subject: Make sure that make_create_in_sticky() never sees uninitialized value of dir_mode
X-Git-Tag: accepted/tizen/unified/20230118.172025~8167^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1a97d899ecbc4b60c8e8f9b41cde443510b5b1bf;p=platform%2Fkernel%2Flinux-rpi.git

Make sure that make_create_in_sticky() never sees uninitialized value of dir_mode

make sure nd->dir_mode is always initialized after success exit from
link_path_walk(); in case of empty path it did not happen.

Reported-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Tested-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/namei.c b/fs/namei.c
index d4a6dd7..fc193c6 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2114,8 +2114,10 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 		return PTR_ERR(name);
 	while (*name=='/')
 		name++;
-	if (!*name)
+	if (!*name) {
+		nd->dir_mode = 0; // short-circuit the 'hardening' idiocy
 		return 0;
+	}
 
 	/* At this point we know we have a real path component. */
 	for(;;) {