UBI: block: fix dereference on uninitialized dev

commit 4df38926f337 ("UBI: block: Avoid disk size integer overflow")
introduced a dereference on dev (which is not initialized at that
point) when printing a warning message.  Re-order disk_capacity check
after the dev is found.

Found by cppcheck:
 [drivers/mtd/ubi/block.c:509]: (error) Uninitialized variable: dev

Artem: tweak the error message a bit

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 33c64955d4d7b3e4bd1d9fc09b08b42b1113db34..518792b7634dbd14930e4215063394179f8d7bf3 100644 (file)
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -504,11 +504,6 @@ static int ubiblock_resize(struct ubi_volume_info *vi)
        struct ubiblock *dev;
        u64 disk_capacity = ((u64)vi->size * vi->usable_leb_size) >> 9;
 
-       if ((sector_t)disk_capacity != disk_capacity) {
-               ubi_warn("%s: the volume is too big, cannot resize (%d LEBs)",
-                        dev->gd->disk_name, vi->size);
-               return -EFBIG;
-       }
        /*
         * Need to lock the device list until we stop using the device,
         * otherwise the device struct might get released in
@@ -520,6 +515,12 @@ static int ubiblock_resize(struct ubi_volume_info *vi)
                mutex_unlock(&devices_mutex);
                return -ENODEV;
        }
+       if ((sector_t)disk_capacity != disk_capacity) {
+               mutex_unlock(&devices_mutex);
+               ubi_warn("%s: the volume is too big (%d LEBs), cannot resize",
+                        dev->gd->disk_name, vi->size);
+               return -EFBIG;
+       }
 
        mutex_lock(&dev->dev_mutex);
        set_capacity(dev->gd, disk_capacity);