This is a note to let you know that I've just added the patch titled
btree: fix tree corruption in btree_get_prev()
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btree-fix-tree-corruption-in-btree_get_prev.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From cbf8ae32f66a9ceb8907ad9e16663c2a29e48990 Mon Sep 17 00:00:00 2001
From: Roland Dreier <rol...@purestorage.com>
Date: Thu, 7 Jun 2012 14:21:13 -0700
Subject: btree: fix tree corruption in btree_get_prev()
From: Roland Dreier <rol...@purestorage.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.
[a...@linux-foundation.org: avoid the double longcpy()]
Signed-off-by: Roland Dreier <rol...@purestorage.com>
Acked-by: Joern Engel <jo...@logfs.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.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;
}
Patches currently in stable-queue which might be from rol...@purestorage.com are
queue-3.0/btree-fix-tree-corruption-in-btree_get_prev.patch
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