crush: fix a bug in tree bucket decode

commit 82cd003a77173c91b9acad8033fb7931dac8d751 upstream. struct crush_bucket_tree::num_nodes is u8, so ceph_decode_8_safe() should be used. -Wconversion catches this, but I guess it went unnoticed in all the noise it spews. The actual problem (at least for common crushmaps) isn't the u32 -> u8 truncation though - it's the advancement by 4 bytes instead of 1 in the crushmap buffer. Fixes: http://tracker.ceph.com/issues/2759 Signed-off-by: Ilya Dryomov <[email protected]> Reviewed-by: Josh Durgin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
lettuce-oreo · Aug 3, 2015 · 7546f8c · 7546f8c
1 parent cc522c5
commit 7546f8c
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
@@ -89,7 +89,7 @@ static int crush_decode_tree_bucket(void **p, void *end,
 {
 	int j;
 	dout("crush_decode_tree_bucket %p to %p\n", *p, end);
-	ceph_decode_32_safe(p, end, b->num_nodes, bad);
+	ceph_decode_8_safe(p, end, b->num_nodes, bad);
 	b->node_weights = kcalloc(b->num_nodes, sizeof(u32), GFP_NOFS);
 	if (b->node_weights == NULL)
 		return -ENOMEM;