From: Roger Pau Monne Date: Fri, 1 Jul 2022 06:23:54 +0000 (+0200) Subject: xen/blkfront: fix leaking data in shared pages X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2f446ffe9d737e9a844b97887919c4fda18246e7;p=linux.git xen/blkfront: fix leaking data in shared pages 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 --- diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 33f04ef78984c..4b3bef6ace68f 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);