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authorRoland Dreier <roland@purestorage.com>2012-06-07 21:21:13 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2012-06-07 21:43:55 (GMT)
commitcbf8ae32f66a9ceb8907ad9e16663c2a29e48990 (patch)
tree0e290072f6c077fffeafd74b540c7536e3aa9873 /lib/btree.c
parent7d8a45695cc8f9fcdf4121fcbd897ecb63f758e4 (diff)
btree: fix tree corruption in btree_get_prev()
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@linux-foundation.org: avoid the double longcpy()] Signed-off-by: Roland Dreier <roland@purestorage.com> Acked-by: Joern Engel <joern@logfs.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/btree.c')
-rw-r--r--lib/btree.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/btree.c b/lib/btree.c
index e5ec1e9..5cf9e74 100644
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -319,8 +319,8 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo,
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;
}

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