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drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl 

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>
alistair/sunxi64-5.4-dsi
Miroslav Lichvar 2019-07-16 16:30:09 -07:00 committed by Linus Torvalds
parent f57e515a1b
commit 5515e9a627
1 changed files with 8 additions and 0 deletions
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8
drivers/pps/pps.c
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@ -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;