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authorBernd Porr <mail@berndporr.me.uk>2013-12-11 16:06:15 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-29 05:06:18 -0800
commitaf7b2d49ef7b4171ef416b7ca2810834993afbca (patch)
parent1b8c5f8b4b57c574f6cf2047e80e1565b2a07f09 (diff)
staging: comedi: fix result of memdup_user for user chanlist
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 <mail@berndporr.me.uk> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index f3d59e2a1152..341decfb81d1 100644
--- 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_device *dev,
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 comedi_device *dev,
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;