Return-path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:36495 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751635AbcIUQ3a (ORCPT ); Wed, 21 Sep 2016 12:29:30 -0400 From: Christian Lamparter To: Greg KH Cc: Christian Lamparter , Kalle Valo , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, Nicolai Stange , Ben Greear , Larry Finger Subject: Re: [PATCH 2/4] carl9170: fix debugfs crashes Date: Wed, 21 Sep 2016 18:29:26 +0200 Message-ID: <1927662.l0xhZ6GL0u@debian64> (sfid-20160921_182951_220533_454DF8F9) In-Reply-To: <20160921101325.GA22263@kroah.com> References: <48411543620969bebb37a1a9ea7b8f451cdfdd31.1474140477.git.chunkeey@gmail.com> <20160921101325.GA22263@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wednesday, September 21, 2016 12:13:25 PM CEST Greg KH wrote: > On Sat, Sep 17, 2016 at 09:43:02PM +0200, Christian Lamparter wrote: > > 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 > > Acked-by: Kalle Valo > > Cc: stable # 4.7+ > > --- > > 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; > > What tree is this against? I can't apply it to 4.8-rc5, or 4.8-rc7, are > you sure it is still needed? --- Yes, the patch is needed. That said I screwed this patch up and as a result it is faulty. I'll send out v2 shortly Thanks, Christian