linux-kernel - [ 02/20] btree: fix tree corruption in btree_get

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <20120614235644.492193053@linuxfoundation.org>
Date:	Thu, 14 Jun 2012 16:56:46 -0700
From:	Greg KH <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Roland Dreier <roland@...estorage.com>,
	Joern Engel <joern@...fs.org>
Subject: [ 02/20] btree: fix tree corruption in btree_get_prev()

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Roland Dreier <roland@...estorage.com>

commit cbf8ae32f66a9ceb8907ad9e16663c2a29e48990 upstream.

The memory the parameter __key points to is used as an iterator in
btree_get_prev(), so if we save off a bkey() pointer in retry_key and
then assign that to __key, we'll end up corrupting the btree internals
when we do eg

	longcpy(__key, bkey(geo, node, i), geo->keylen);

to return the key value.  What we should do instead is use longcpy() to
copy the key value that retry_key points to __key.

This can cause a btree to get corrupted by seemingly read-only
operations such as btree_for_each_safe.

[akpm@...ux-foundation.org: avoid the double longcpy()]
Signed-off-by: Roland Dreier <roland@...estorage.com>
Acked-by: Joern Engel <joern@...fs.org>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 lib/btree.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/lib/btree.c
+++ b/lib/btree.c
@@ -319,8 +319,8 @@ void *btree_get_prev(struct btree_head *
 
 	if (head->height == 0)
 		return NULL;
-retry:
 	longcpy(key, __key, geo->keylen);
+retry:
 	dec_key(geo, key);
 
 	node = head->node;
@@ -351,7 +351,7 @@ retry:
 	}
 miss:
 	if (retry_key) {
-		__key = retry_key;
+		longcpy(key, retry_key, geo->keylen);
 		retry_key = NULL;
 		goto retry;
 	}


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/