[278/289] rds: Integer overflow in RDS cmsg handling

Greg KH
2010-12-08T01:06:59Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

commit 218854af84038d828a32f061858b1902ed2beec6 upstream.

In rds_cmsg_rdma_args(), the user-provided args->nr_local value is
restricted to less than UINT_MAX. This seems to need a tighter upper
bound, since the calculation of total iov_size can overflow, resulting
in a small sock_kmalloc() allocation. This would probably just result
in walking off the heap and crashing when calling rds_rdma_pages() with
a high count value. If it somehow doesn't crash here, then memory
corruption could occur soon after.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/rds/rdma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -474,7 +474,7 @@ static struct rds_rdma_op *rds_rdma_prep
goto out;
}

- if (args->nr_local > (u64)UINT_MAX) {
+ if (args->nr_local > UIO_MAXIOV) {
ret = -EMSGSIZE;
goto out;
}