block: sunvdc: add check for mdesc_grab() returning NULL
authorLiang He <windhl@126.com>
Wed, 15 Mar 2023 06:20:32 +0000 (14:20 +0800)
committerJens Axboe <axboe@kernel.dk>
Wed, 15 Mar 2023 14:48:58 +0000 (08:48 -0600)
In vdc_port_probe(), we should check the return value of mdesc_grab() as
it may return NULL, which can cause potential NPD bug.

Fixes: 43fdf27470b2 ("[SPARC64]: Abstract out mdesc accesses for better MD update handling.")
Signed-off-by: Liang He <windhl@126.com>
Link: https://lore.kernel.org/r/20230315062032.1741692-1-windhl@126.com
[axboe: style cleanup]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block/sunvdc.c

index fb855da..9fa821f 100644 (file)
@@ -972,6 +972,8 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
        print_version();
 
        hp = mdesc_grab();
+       if (!hp)
+               return -ENODEV;
 
        err = -ENODEV;
        if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {