3.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: Roland Dreier <[email protected]> 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. [[email protected]: avoid the double longcpy()] Signed-off-by: Roland Dreier <[email protected]> Acked-by: Joern Engel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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 stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
