pps: add an error check in parport_attach

commit 62c5a01a5711c8e4be8ae7b6f0db663094615d48 upstream.

In parport_attach, the return value of ida_alloc is unchecked, witch leads
to the use of an invalid index value.

To address this issue, index should be checked. When the index value is
abnormal, the device should be freed.

Found by code review, compile tested only.

Cc: stable@vger.kernel.org
Fixes: fb56d97df70e ("pps: client: use new parport device model")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20240828131814.3034338-1-make24@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pps/clients/pps_parport.c b/drivers/pps/clients/pps_parport.c
index af972cdc04b53c8e7fec0b1456b97489c744006f..53e9c304ae0a7a7011d34c2cc49f05331495688c 100644 (file)
--- a/drivers/pps/clients/pps_parport.c
+++ b/drivers/pps/clients/pps_parport.c
@@ -149,6 +149,9 @@ static void parport_attach(struct parport *port)
        }
 
        index = ida_alloc(&pps_client_index, GFP_KERNEL);
+       if (index < 0)
+               goto err_free_device;
+
        memset(&pps_client_cb, 0, sizeof(pps_client_cb));
        pps_client_cb.private = device;
        pps_client_cb.irq_func = parport_irq;
@@ -159,7 +162,7 @@ static void parport_attach(struct parport *port)
                                                    index);
        if (!device->pardev) {
                pr_err("couldn't register with %s\n", port->name);
-               goto err_free;
+               goto err_free_ida;
        }
 
        if (parport_claim_or_block(device->pardev) < 0) {
@@ -187,8 +190,9 @@ err_release_dev:
        parport_release(device->pardev);
 err_unregister_dev:
        parport_unregister_device(device->pardev);
-err_free:
+err_free_ida:
        ida_free(&pps_client_index, index);
+err_free_device:
        kfree(device);
 }