From e56b1401056288a725d50942ef300dcbed5e519a Mon Sep 17 00:00:00 2001 From: Bernd Porr Date: Wed, 11 Dec 2013 16:06:15 +0000 Subject: [PATCH] staging: comedi: fix result of memdup_user for user chanlist 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(+) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index fc34048..d7f63c4 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1473,6 +1473,7 @@ static int do_cmd_ioctl(struct comedi_device *dev, async->cmd.chanlist_len * sizeof(int)); if (IS_ERR(async->cmd.chanlist)) { ret = PTR_ERR(async->cmd.chanlist); + async->cmd.chanlist = NULL; dev_dbg(dev->class_dev, "memdup_user failed with code %d\n", ret); goto cleanup; @@ -1595,6 +1596,7 @@ static int do_cmdtest_ioctl(struct comedi_device *dev, cmd.chanlist_len * sizeof(int)); if (IS_ERR(chanlist)) { ret = PTR_ERR(chanlist); + chanlist = NULL; dev_dbg(dev->class_dev, "memdup_user exited with code %d", ret); goto cleanup; -- 2.7.4