btree: catch NULL value before it does harm

Storing NULL values in the btree is illegal and can lead to memory
corruption and possible other fun as well.  Catch it on insert, instead
of waiting for the inevitable.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/btree.c b/lib/btree.c
index 5cf9e74ec3f32a9f0d7fbb247b79f0815ce981b6..f9a484676cb6a8e4782333ce164bf0662b583b78 100644 (file)
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -509,6 +509,7 @@ retry:
 int btree_insert(struct btree_head *head, struct btree_geo *geo,
                unsigned long *key, void *val, gfp_t gfp)
 {
+       BUG_ON(!val);
        return btree_insert_level(head, geo, key, val, 1, gfp);
 }
 EXPORT_SYMBOL_GPL(btree_insert);