From: Jan Beulich <jbeulich@suse.com> stable inclusion from linux-4.19.177 commit f84c00fbd27b043fa42a56eaaa14e293877bc69b CVE: CVE-2021-26931 -------------------------------- commit 7c77474b2d22176d2bfb592ec74e0f2cb71352c9 upstream. In particular -ENOMEM may come back here, from set_foreign_p2m_mapping(). Don't make problems worse, the more that handling elsewhere (together with map's status fields now indicating whether a mapping wasn't even attempted, and hence has to be considered failed) doesn't require this odd way of dealing with errors. This is part of XSA-362. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> --- drivers/xen/xen-scsiback.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c index 1abc0a55b8d9..614d067ffe12 100644 --- a/drivers/xen/xen-scsiback.c +++ b/drivers/xen/xen-scsiback.c @@ -422,12 +422,12 @@ static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, return 0; err = gnttab_map_refs(map, NULL, pg, cnt); - BUG_ON(err); for (i = 0; i < cnt; i++) { if (unlikely(map[i].status != GNTST_okay)) { pr_err("invalid buffer -- could not remap it\n"); map[i].handle = SCSIBACK_INVALID_HANDLE; - err = -ENOMEM; + if (!err) + err = -ENOMEM; } else { get_page(pg[i]); } -- 2.25.1