From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bernd Porr , Ian Abbott Subject: [PATCH 3.13 02/10] staging: comedi: fix result of memdup_user for user chanlist Date: Mon, 27 Jan 2014 12:17:05 -0800 Message-Id: <20140127201535.520608166@linuxfoundation.org> In-Reply-To: <20140127201535.350372282@linuxfoundation.org> References: <20140127201535.350372282@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bernd Porr commit e56b1401056288a725d50942ef300dcbed5e519a upstream. If the channel list is not set in userspace we get an error at PTR_ERR(async->cmd.chanlist). However, do_become_nonbusy(dev, s) cleans up this pointer which causes a kernel ooops. Setting the channel list in async to NULL and checking this in do_become_nonbusy prevents the oops. [Ian Abbott] Also do the same for the chanlist allocated in do_cmdtest_ioctl(). Signed-off-by: Bernd Porr Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1425,6 +1425,7 @@ static int do_cmd_ioctl(struct comedi_de async->cmd.chanlist_len * sizeof(int)); if (IS_ERR(async->cmd.chanlist)) { ret = PTR_ERR(async->cmd.chanlist); + async->cmd.chanlist = NULL; DPRINTK("memdup_user failed with code %d\n", ret); goto cleanup; } @@ -1547,6 +1548,7 @@ static int do_cmdtest_ioctl(struct comed cmd.chanlist_len * sizeof(int)); if (IS_ERR(chanlist)) { ret = PTR_ERR(chanlist); + chanlist = NULL; DPRINTK("memdup_user exited with code %d", ret); goto cleanup; }