linux-kernel - [PATCH 1/1] xen: set error code on failures

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Sun,  4 Dec 2016 14:24:36 +0800
From:   Pan Bian <bianpan201604@....com>
To:     Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        David Vrabel <david.vrabel@...rix.com>,
        Juergen Gross <jgross@...e.com>, xen-devel@...ts.xenproject.org
Cc:     linux-kernel@...r.kernel.org, Pan Bian <bianpan2016@....com>
Subject: [PATCH 1/1] xen: set error code on failures

From: Pan Bian <bianpan2016@....com>

The return variable rc is initialized with "-ENOMEM" outside the loop.
However, it is reset in the loop, and its value is not negative during 
the second or after repeat of the loop. If kzalloc() fails then, it will 
return 0. This patch fixes the bug, assigning "-ENOMEM" to rc when 
kzalloc() or alloc_page() returns NULL.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=189111

Signed-off-by: Pan Bian <bianpan2016@....com>
---
 drivers/xen/gntalloc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
index 7a47c4c..55ef246 100644
--- a/drivers/xen/gntalloc.c
+++ b/drivers/xen/gntalloc.c
@@ -130,15 +130,19 @@ static int add_grefs(struct ioctl_gntalloc_alloc_gref *op,
 	rc = -ENOMEM;
 	for (i = 0; i < op->count; i++) {
 		gref = kzalloc(sizeof(*gref), GFP_KERNEL);
-		if (!gref)
+		if (!gref) {
+			rc = -ENOMEM;
 			goto undo;
+		}
 		list_add_tail(&gref->next_gref, &queue_gref);
 		list_add_tail(&gref->next_file, &queue_file);
 		gref->users = 1;
 		gref->file_index = op->index + i * PAGE_SIZE;
 		gref->page = alloc_page(GFP_KERNEL|__GFP_ZERO);
-		if (!gref->page)
+		if (!gref->page) {
+			rc = -ENOMEM;
 			goto undo;
+		}
 
 		/* Grant foreign access to the page. */
 		rc = gnttab_grant_foreign_access(op->domid,
-- 
1.9.1