linux-kernel - [PATCH v2 3/3] xen-blkfront: transverse list of persistent grants safely

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 for Android: free password hash cracker in your pocket

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

Message-ID: <1355160290-22180-3-git-send-email-roger.pau@citrix.com>
Date:	Mon, 10 Dec 2012 18:24:50 +0100
From:	Roger Pau Monne <roger.pau@...rix.com>
To:	<linux-kernel@...r.kernel.org>
CC:	Roger Pau Monne <roger.pau@...rix.com>,
	Konrad Rzeszutek Wilk <konrad@...nel.org>,
	<xen-devel@...ts.xen.org>
Subject: [PATCH v2 3/3] xen-blkfront: transverse list of persistent grants safely

Use llist_for_each_entry_safe in blkif_free. Previously grants where
freed while iterating the list, which lead to dereferences when trying
to fetch the next item.

Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Roger Pau Monné <roger.pau@...rix.com>
Cc: Konrad Rzeszutek Wilk <konrad@...nel.org>
Cc: xen-devel@...ts.xen.org
---
 drivers/block/xen-blkfront.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 96e9b00..cfdb033 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -792,6 +792,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 {
 	struct llist_node *all_gnts;
 	struct grant *persistent_gnt;
+	struct llist_node *n;
 
 	/* Prevent new requests being issued until we fix things up. */
 	spin_lock_irq(&info->io_lock);
@@ -804,7 +805,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 	/* Remove all persistent grants */
 	if (info->persistent_gnts_c) {
 		all_gnts = llist_del_all(&info->persistent_gnts);
-		llist_for_each_entry(persistent_gnt, all_gnts, node) {
+		llist_for_each_entry_safe(persistent_gnt, n, all_gnts, node) {
 			gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
 			__free_page(pfn_to_page(persistent_gnt->pfn));
 			kfree(persistent_gnt);
-- 
1.7.7.5 (Apple Git-26)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/