From 2f446ffe9d737e9a844b97887919c4fda18246e7 Mon Sep 17 00:00:00 2001 From: Roger Pau Monne Date: Fri, 1 Jul 2022 08:23:54 +0200 Subject: [PATCH] xen/blkfront: fix leaking data in shared pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When allocating pages to be used for shared communication with the backend always zero them, this avoids leaking unintended data present on the pages. This is CVE-2022-26365, part of XSA-403. Signed-off-by: Roger Pau Monné Reviewed-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/block/xen-blkfront.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 33f04ef78984..4b3bef6ace68 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -311,7 +311,7 @@ static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num) goto out_of_memory; if (info->feature_persistent) { - granted_page = alloc_page(GFP_NOIO); + granted_page = alloc_page(GFP_NOIO | __GFP_ZERO); if (!granted_page) { kfree(gnt_list_entry); goto out_of_memory; @@ -2183,7 +2183,8 @@ static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) BUG_ON(!list_empty(&rinfo->indirect_pages)); for (i = 0; i < num; i++) { - struct page *indirect_page = alloc_page(GFP_KERNEL); + struct page *indirect_page = alloc_page(GFP_KERNEL | + __GFP_ZERO); if (!indirect_page) goto out_of_memory; list_add(&indirect_page->lru, &rinfo->indirect_pages);