rapidio: handle create_workqueue() failure

In case create_workqueue() fails, release all resources and return -ENOMEM
to caller to avoid potential NULL pointer deref later. Move up the
create_workequeue() call to return early and avoid unwinding the call to
riocm_rx_fill().

Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20210503115736.2104747-46-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index e6c16f04f2b45318aeaf44aae6a869ac12395d2a..db4c265287ae6e1fdaadb62e291157cacbcb5251 100644 (file)
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -2127,6 +2127,14 @@ static int riocm_add_mport(struct device *dev,
                return -ENODEV;
        }
 
+       cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
+       if (!cm->rx_wq) {
+               rio_release_inb_mbox(mport, cmbox);
+               rio_release_outb_mbox(mport, cmbox);
+               kfree(cm);
+               return -ENOMEM;
+       }
+
        /*
         * Allocate and register inbound messaging buffers to be ready
         * to receive channel and system management requests
@@ -2137,7 +2145,6 @@ static int riocm_add_mport(struct device *dev,
        cm->rx_slots = RIOCM_RX_RING_SIZE;
        mutex_init(&cm->rx_lock);
        riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
-       cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
        INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
 
        cm->tx_slot = 0;