linux-kernel - [PATCH] staging: zcache: fix possible sleep under lock

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]

Message-Id: <1314038869-8164-1-git-send-email-sjenning@linux.vnet.ibm.com>
Date:	Mon, 22 Aug 2011 13:47:49 -0500
From:	Seth Jennings <sjenning@...ux.vnet.ibm.com>
To:	gregkh@...e.de
Cc:	ascardo@...oscopio.com, dan.magenheimer@...cle.com,
	sjenning@...ux.vnet.ibm.com, rdunlap@...otime.net,
	devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: [PATCH] staging: zcache: fix possible sleep under lock

zcache_new_pool() calls kmalloc() with GFP_KERNEL which has
__GFP_WAIT set.  However, zcache_new_pool() gets called on
a stack that holds the swap_lock spinlock, leading to a
possible sleep-with-lock situation. The lock is obtained
in enable_swap_info().

The patch replaces GFP_KERNEL with GFP_IOFS, which is
GFP_KERNEL & ~__GFP_WAIT.

Signed-off-by: Seth Jennings <sjenning@...ux.vnet.ibm.com>
---
 drivers/staging/zcache/zcache-main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 855a5bb..96ca0ee 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1668,7 +1668,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
 	if (cli == NULL)
 		goto out;
 	atomic_inc(&cli->refcount);
-	pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL);
+	pool = kmalloc(sizeof(struct tmem_pool), GFP_IOFS);
 	if (pool == NULL) {
 		pr_info("zcache: pool creation failed: out of memory\n");
 		goto out;
-- 
1.7.4.1

--
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/