From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Sun, 17 Sep 2017 08:32:20 +0000 (+0200)
Subject: ubifs: Fix uninitialized variable in search_dh_cookie()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2a71a742f09b390a200110dd3d8ff9f6f51f9443;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

ubifs: Fix uninitialized variable in search_dh_cookie()


[ Upstream commit c877154d307f4a91e0b5b85b75535713dab945ae ]

fs/ubifs/tnc.c: In function ‘search_dh_cookie’:
fs/ubifs/tnc.c:1893: warning: ‘err’ is used uninitialized in this function

Indeed, err is always used uninitialized.

According to an original review comment from Hyunchul, acknowledged by
Richard, err should be initialized to -ENOENT to avoid the first call to
tnc_next().  But we can achieve the same by reordering the code.

Fixes: 781f675e2d7e ("ubifs: Fix unlink code wrt. double hash lookups")
Reported-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 0a213dcba2a1..ba3d0e0f8615 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -1890,35 +1890,28 @@ static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key,
 	union ubifs_key *dkey;
 
 	for (;;) {
-		if (!err) {
-			err = tnc_next(c, &znode, n);
-			if (err)
-				goto out;
-		}
-
 		zbr = &znode->zbranch[*n];
 		dkey = &zbr->key;
 
 		if (key_inum(c, dkey) != key_inum(c, key) ||
 		    key_type(c, dkey) != key_type(c, key)) {
-			err = -ENOENT;
-			goto out;
+			return -ENOENT;
 		}
 
 		err = tnc_read_hashed_node(c, zbr, dent);
 		if (err)
-			goto out;
+			return err;
 
 		if (key_hash(c, key) == key_hash(c, dkey) &&
 		    le32_to_cpu(dent->cookie) == cookie) {
 			*zn = znode;
-			goto out;
+			return 0;
 		}
-	}
-
-out:
 
-	return err;
+		err = tnc_next(c, &znode, n);
+		if (err)
+			return err;
+	}
 }
 
 static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,