iwlwifi: dbg_ini: fix memory leak in alloc_sgtable

mainline inclusion
from mainline-v5.4-rc6
commit b4b814fec1a5a849383f7b3886b654a13abbda7d
category: bugfix
bugzilla: 13690
CVE: CVE-2019-19058

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

In alloc_sgtable if alloc_page fails, the alocated table should be
released.
Signed-off-by: NNavid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NWenan Mao <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/wireless/intel/iwlwifi/fw/dbg.c

@@ -547,6 +547,7 @@ static struct scatterlist *alloc_sgtable(int size)
 				if (new_page)
 					__free_page(new_page);
 			}
+			kfree(table);
 			return NULL;
 		}
 		alloc_size = min_t(int, size, PAGE_SIZE);