Commit 2a71a742 authored Sep 17, 2017 by Geert Uytterhoeven Committed by Greg Kroah-Hartman Apr 26, 2018

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: 781f675e ("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>

parent a1dfcb01

fs/ubifs/tnc.c

+7 −14

Original line number	Diff line number	Diff line
		@@ -1890,36 +1890,29 @@ 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:

		err = tnc_next(c, &znode, n);
		if (err)
		return err;
		}
		}

		static int do_lookup_dh(struct ubifs_info c, const union ubifs_key key,
		struct ubifs_dent_node *dent, uint32_t cookie)