linux-kernel - [PATCH 4.9 222/223] drivers/pps/pps.c: clear offset flags in PPS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190802092250.950010784@linuxfoundation.org>
Date:   Fri,  2 Aug 2019 11:37:27 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Miroslav Lichvar <mlichvar@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Rodolfo Giometti <giometti@...eenne.com>,
        Greg KH <greg@...ah.com>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: [PATCH 4.9 222/223] drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl

From: Miroslav Lichvar <mlichvar@...hat.com>

commit 5515e9a6273b8c02034466bcbd717ac9f53dab99 upstream.

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@...hat.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
Acked-by: Rodolfo Giometti <giometti@...eenne.com>
Cc: Greg KH <greg@...ah.com>
Cc: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/pps/pps.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -129,6 +129,14 @@ static long pps_cdev_ioctl(struct 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;