RDMA/iwcm: Don't copy past the end of dev_name() string

We now use dev_name(&ib_device->dev) instead of ib_device->name in iwpm
messages.  The name field in struct device is a const char *, where as
ib_device->name is a char array of size IB_DEVICE_NAME_MAX, and it is
pre-initialized to zeros.

Since iw_cm_map() was using memcpy() to copy in the device name, and
copying IWPM_DEVNAME_SIZE bytes, it ends up copying past the end of the
source device name string and copying random bytes.  This results in iwpmd
failing the REGISTER_PID request from iwcm.  Thus port mapping is broken.

Validate the device and if names, and use strncpy() to inialize the entire
message field.

Fixes: 896de0090a ("RDMA/core: Use dev_name instead of ibdev->name")
Cc: stable@vger.kernel.org
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Steve Wise 2018-12-20 14:00:11 -08:00 committed by Jason Gunthorpe
parent bb7e22a8ab
commit d53ec8af56

View file

@ -502,17 +502,21 @@ static void iw_cm_check_wildcard(struct sockaddr_storage *pm_addr,
*/
static int iw_cm_map(struct iw_cm_id *cm_id, bool active)
{
const char *devname = dev_name(&cm_id->device->dev);
const char *ifname = cm_id->device->iwcm->ifname;
struct iwpm_dev_data pm_reg_msg;
struct iwpm_sa_data pm_msg;
int status;
if (strlen(devname) >= sizeof(pm_reg_msg.dev_name) ||
strlen(ifname) >= sizeof(pm_reg_msg.if_name))
return -EINVAL;
cm_id->m_local_addr = cm_id->local_addr;
cm_id->m_remote_addr = cm_id->remote_addr;
memcpy(pm_reg_msg.dev_name, dev_name(&cm_id->device->dev),
sizeof(pm_reg_msg.dev_name));
memcpy(pm_reg_msg.if_name, cm_id->device->iwcm->ifname,
sizeof(pm_reg_msg.if_name));
strncpy(pm_reg_msg.dev_name, devname, sizeof(pm_reg_msg.dev_name));
strncpy(pm_reg_msg.if_name, ifname, sizeof(pm_reg_msg.if_name));
if (iwpm_register_pid(&pm_reg_msg, RDMA_NL_IWCM) ||
!iwpm_valid_pid())