From: Miroslav Lichvar mlichvar@redhat.com
[ Upstream commit 5515e9a6273b8c02034466bcbd717ac9f53dab99 ]
The PPS assert/clear offset corrections are set by the PPS_SETPARAMS ioctl in the pps_ktime structs, which also contain flags. The flags are not initialized by applications (using the timepps.h header) and they are not used by the kernel for anything except returning them back in the PPS_GETPARAMS ioctl.
Set the flags to zero to make it clear they are unused and avoid leaking uninitialized data of the PPS_SETPARAMS caller to other applications that have a read access to the PPS device.
Link: http://lkml.kernel.org/r/20190702092251.24303-1-mlichvar@redhat.com Signed-off-by: Miroslav Lichvar mlichvar@redhat.com Reviewed-by: Thomas Gleixner tglx@linutronix.de Acked-by: Rodolfo Giometti giometti@enneenne.com Cc: Greg KH greg@kroah.com Cc: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pps/pps.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c index 3a546ec10d90..22a65ad4e46e 100644 --- a/drivers/pps/pps.c +++ b/drivers/pps/pps.c @@ -152,6 +152,14 @@ static long pps_cdev_ioctl(struct file *file, pps->params.mode |= PPS_CANWAIT; pps->params.api_version = PPS_API_VERS;
+ /* + * Clear unused fields of pps_kparams to avoid leaking + * uninitialized data of the PPS_SETPARAMS caller via + * PPS_GETPARAMS + */ + pps->params.assert_off_tu.flags = 0; + pps->params.clear_off_tu.flags = 0; + spin_unlock_irq(&pps->lock);
break;