linux-kernel - [PATCH 4.9 37/83] dm btree: fix order of block initialization in btree_split

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190904175307.155331427@linuxfoundation.org>
Date:   Wed,  4 Sep 2019 19:53:29 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, ZhangXiaoxu <zhangxiaoxu5@...wei.com>,
        Mike Snitzer <snitzer@...hat.com>
Subject: [PATCH 4.9 37/83] dm btree: fix order of block initialization in btree_split_beneath

From: ZhangXiaoxu <zhangxiaoxu5@...wei.com>

commit e4f9d6013820d1eba1432d51dd1c5795759aa77f upstream.

When btree_split_beneath() splits a node to two new children, it will
allocate two blocks: left and right.  If right block's allocation
failed, the left block will be unlocked and marked dirty.  If this
happened, the left block'ss content is zero, because it wasn't
initialized with the btree struct before the attempot to allocate the
right block.  Upon return, when flushing the left block to disk, the
validator will fail when check this block.  Then a BUG_ON is raised.

Fix this by completely initializing the left block before allocating and
initializing the right block.

Fixes: 4dcb8b57df359 ("dm btree: fix leak of bufio-backed block in btree_split_beneath error path")
Cc: stable@...r.kernel.org
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@...wei.com>
Signed-off-by: Mike Snitzer <snitzer@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/md/persistent-data/dm-btree.c |   31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -623,39 +623,40 @@ static int btree_split_beneath(struct sh
 
 	new_parent = shadow_current(s);
 
+	pn = dm_block_data(new_parent);
+	size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
+		sizeof(__le64) : s->info->value_type.size;
+
+	/* create & init the left block */
 	r = new_block(s->info, &left);
 	if (r < 0)
 		return r;
 
+	ln = dm_block_data(left);
+	nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
+
+	ln->header.flags = pn->header.flags;
+	ln->header.nr_entries = cpu_to_le32(nr_left);
+	ln->header.max_entries = pn->header.max_entries;
+	ln->header.value_size = pn->header.value_size;
+	memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
+	memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
+
+	/* create & init the right block */
 	r = new_block(s->info, &right);
 	if (r < 0) {
 		unlock_block(s->info, left);
 		return r;
 	}
 
-	pn = dm_block_data(new_parent);
-	ln = dm_block_data(left);
 	rn = dm_block_data(right);
-
-	nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
 	nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;
 
-	ln->header.flags = pn->header.flags;
-	ln->header.nr_entries = cpu_to_le32(nr_left);
-	ln->header.max_entries = pn->header.max_entries;
-	ln->header.value_size = pn->header.value_size;
-
 	rn->header.flags = pn->header.flags;
 	rn->header.nr_entries = cpu_to_le32(nr_right);
 	rn->header.max_entries = pn->header.max_entries;
 	rn->header.value_size = pn->header.value_size;
-
-	memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
 	memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));
-
-	size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
-		sizeof(__le64) : s->info->value_type.size;
-	memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
 	memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
 	       nr_right * size);