private_data_len is defined as a u8. If the user specifies a large private_data size (> 220 bytes), we will calculate a total length that exceeds 255, resulting in private_data_len wrapping back to 0. This can lead to overwriting random kernel memory. Avoid this by verifying that the resulting size fits into a u8.
Problem reported by B. Thery, OFA bug 2335. Signed-off-by: Sean Hefty <[email protected]> --- Please consider queuing for 3.2 if it's not too late. This bug has been around for a while though, so hitting 3.3 is fine. drivers/infiniband/core/cma.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index c3a0c62..fdd8ef8 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -2513,6 +2513,9 @@ static int cma_resolve_ib_udp(struct rdma_id_private *id_priv, req.private_data_len = sizeof(struct cma_hdr) + conn_param->private_data_len; + if (req.private_data_len < conn_param->private_data_len) + return -EINVAL; + req.private_data = kzalloc(req.private_data_len, GFP_ATOMIC); if (!req.private_data) return -ENOMEM; @@ -2562,6 +2565,9 @@ static int cma_connect_ib(struct rdma_id_private *id_priv, memset(&req, 0, sizeof req); offset = cma_user_data_offset(id_priv->id.ps); req.private_data_len = offset + conn_param->private_data_len; + if (req.private_data_len < conn_param->private_data_len) + return -EINVAL; + private_data = kzalloc(req.private_data_len, GFP_ATOMIC); if (!private_data) return -ENOMEM; -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
