[PATCH 4.14 29/50] dm: eliminate potential source of excessive kernel log noise

Greg Kroah-Hartman
2021-01-22T19:06:00Z

From: Mike Snitzer <snitzer@redhat.com>

commit 0378c625afe80eb3f212adae42cc33c9f6f31abf upstream.

There wasn't ever a real need to log an error in the kernel log for
ioctls issued with insufficient permissions. Simply return an error
and if an admin/user is sufficiently motivated they can enable DM's
dynamic debugging to see an explanation for why the ioctls were
disallowed.

Reported-by: Nir Soffer <nsoffer@redhat.com>
Fixes: e980f62353c6 ("dm: don't allow ioctls to targets that don't map to whole devices")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -472,7 +472,7 @@ static int dm_blk_ioctl(struct block_dev
* subset of the parent bdev; require extra privileges.
*/
if (!capable(CAP_SYS_RAWIO)) {
- DMWARN_LIMIT(
+ DMDEBUG_LIMIT(
"%s: sending ioctl %x to DM device without required privilege.",
current->comm, cmd);
r = -ENOIOCTLCMD;