linux-kernel - [60/93] devmem: fix kmem write bug on memory holes

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

Message-Id: <20100219163247.144005727@kvm.kroah.org>
Date:	Fri, 19 Feb 2010 08:29:53 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Wu Fengguang <fengguang.wu@...el.com>,
	Andi Kleen <andi@...stfloor.org>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>, Tejun Heo <tj@...nel.org>,
	Nick Piggin <npiggin@...e.de>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Chuck Ebbert <cebbert@...hat.com>
Subject: [60/93] devmem: fix kmem write bug on memory holes

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------


From: Wu Fengguang <fengguang.wu@...el.com>


commit c85e9a97c4102ce2e83112da850d838cfab5ab13 upstream

devmem: fix kmem write bug on memory holes

[ cebbert@...hat.com : backport to 2.6.32 ]

write_kmem() used to assume vwrite() always return the full buffer length.
However now vwrite() could return 0 to indicate memory hole.  This
creates a bug that "buf" is not advanced accordingly.

Fix it to simply ignore the return value, hence the memory hole.

Signed-off-by: Wu Fengguang <fengguang.wu@...el.com>
Cc: Andi Kleen <andi@...stfloor.org>
Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc: Christoph Lameter <cl@...ux-foundation.org>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Tejun Heo <tj@...nel.org>
Cc: Nick Piggin <npiggin@...e.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc: <stable@...nel.org>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Chuck Ebbert <cebbert@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 drivers/char/mem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -593,7 +593,7 @@ static ssize_t write_kmem(struct file *
 					break;
 				}
 			}
-			len = vwrite(kbuf, (char *)p, len);
+			vwrite(kbuf, (char *)p, len);
 			count -= len;
 			buf += len;
 			virtr += len;


--
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/