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| author | Roland Dreier <roland@purestorage.com> | 2012-06-07 14:21:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-07 14:43:55 -0700 |
| commit | cbf8ae32f66a9ceb8907ad9e16663c2a29e48990 (patch) | |
| tree | 0e290072f6c077fffeafd74b540c7536e3aa9873 /lib/btree.c | |
| parent | 7d8a45695cc8f9fcdf4121fcbd897ecb63f758e4 (diff) | |
| download | lwn-cbf8ae32f66a9ceb8907ad9e16663c2a29e48990.tar.gz lwn-cbf8ae32f66a9ceb8907ad9e16663c2a29e48990.zip | |
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.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/btree.c b/lib/btree.c index e5ec1e9c1aa5..5cf9e74ec3f3 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; } |