[PATCH 5.0 42/52] RDMA/cma: Rollback source IP address if failing to acquire device

From: Greg Kroah-Hartman
Date: Tue Mar 26 2019 - 02:40:56 EST


5.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Myungho Jung <mhjungk@xxxxxxxxx>

commit 5fc01fb846bce8fa6d5f95e2625b8ce0f8e86810 upstream.

If cma_acquire_dev_by_src_ip() returns error in addr_handler(), the
device state changes back to RDMA_CM_ADDR_BOUND but the resolved source
IP address is still left. After that, if rdma_destroy_id() is called
after rdma_listen(), the device is freed without removed from
listen_any_list in cma_cancel_operation(). Revert to the previous IP
address if acquiring device fails.

Reported-by: syzbot+f3ce716af730c8f96637@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Myungho Jung <mhjungk@xxxxxxxxx>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/infiniband/core/cma.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2966,13 +2966,22 @@ static void addr_handler(int status, str
{
struct rdma_id_private *id_priv = context;
struct rdma_cm_event event = {};
+ struct sockaddr *addr;
+ struct sockaddr_storage old_addr;

mutex_lock(&id_priv->handler_mutex);
if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_QUERY,
RDMA_CM_ADDR_RESOLVED))
goto out;

- memcpy(cma_src_addr(id_priv), src_addr, rdma_addr_size(src_addr));
+ /*
+ * Store the previous src address, so that if we fail to acquire
+ * matching rdma device, old address can be restored back, which helps
+ * to cancel the cma listen operation correctly.
+ */
+ addr = cma_src_addr(id_priv);
+ memcpy(&old_addr, addr, rdma_addr_size(addr));
+ memcpy(addr, src_addr, rdma_addr_size(src_addr));
if (!status && !id_priv->cma_dev) {
status = cma_acquire_dev_by_src_ip(id_priv);
if (status)
@@ -2983,6 +2992,8 @@ static void addr_handler(int status, str
}

if (status) {
+ memcpy(addr, &old_addr,
+ rdma_addr_size((struct sockaddr *)&old_addr));
if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_RESOLVED,
RDMA_CM_ADDR_BOUND))
goto out;