Return-path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:36115 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970AbcIQTnK (ORCPT ); Sat, 17 Sep 2016 15:43:10 -0400 From: Christian Lamparter To: gregkh@linuxfoundation.org, Kalle Valo Cc: Christian Lamparter , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, Nicolai Stange , Ben Greear , Larry Finger Subject: [PATCH 2/4] carl9170: fix debugfs crashes Date: Sat, 17 Sep 2016 21:43:02 +0200 Message-Id: (sfid-20160917_214338_765581_0F26AE8C) In-Reply-To: <48411543620969bebb37a1a9ea7b8f451cdfdd31.1474140477.git.chunkeey@gmail.com> References: <48411543620969bebb37a1a9ea7b8f451cdfdd31.1474140477.git.chunkeey@gmail.com> In-Reply-To: <48411543620969bebb37a1a9ea7b8f451cdfdd31.1474140477.git.chunkeey@gmail.com> References: <48411543620969bebb37a1a9ea7b8f451cdfdd31.1474140477.git.chunkeey@gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Ben Greear reported: > I see lots of instability as soon as I load up the carl9710 NIC. > My application is going to be poking at it's debugfs files... > > BUG: KASAN: slab-out-of-bounds in carl9170_debugfs_read+0xd5/0x2a0 > [carl9170] at addr ffff8801bc1208b0 > Read of size 8 by task btserver/5888 > ======================================================================= > BUG kmalloc-256 (Tainted: G W ): kasan: bad access detected > ----------------------------------------------------------------------- > > INFO: Allocated in seq_open+0x50/0x100 age=2690 cpu=2 pid=772 >... This breakage was caused by the introduction of intermediate fops in debugfs by commit 9fd4dcece43a ("debugfs: prevent access to possibly dead file_operations at file open") Thankfully, the original/real fops are still available in d_fsdata. Reported-by: Ben Greear Reviewed-by: Nicolai Stange Signed-off-by: Christian Lamparter --- drivers/net/wireless/ath/carl9170/debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/carl9170/debug.c b/drivers/net/wireless/ath/carl9170/debug.c index 01a0919..ad7ffd5 100644 --- a/drivers/net/wireless/ath/carl9170/debug.c +++ b/drivers/net/wireless/ath/carl9170/debug.c @@ -75,7 +75,7 @@ static ssize_t carl9170_debugfs_read(struct file *file, char __user *userbuf, if (!ar) return -ENODEV; - dfops = container_of(file->f_path.dentry->d_fsdata, + dfops = container_of(debugfs_real_fops(file), struct carl9170_debugfs_fops, fops); if (!dfops->read) @@ -128,7 +128,7 @@ static ssize_t carl9170_debugfs_write(struct file *file, if (!ar) return -ENODEV; - dfops = container_of(file->f_path.dentry->d_fsdata, + dfops = container_of(debugfs_real_fops(file), struct carl9170_debugfs_fops, fops); if (!dfops->write) return -ENOSYS; -- 2.9.3