From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: [PATCH] net: fec: ptp: fix NULL pointer dereference if ptp_clock is not set Date: Wed, 22 Oct 2014 16:34:35 +0200 Message-ID: <1413988475-6565-1-git-send-email-p.zabel@pengutronix.de> Cc: netdev@vger.kernel.org, Philipp Zabel To: "David S. Miller" , Luwei Zhou Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:55932 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752293AbaJVOej (ORCPT ); Wed, 22 Oct 2014 10:34:39 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Since commit 278d24047891 (net: fec: ptp: Enable PPS output based on ptp clock) fec_enet_interrupt calls fec_ptp_check_pps_event unconditionally, which calls into ptp_clock_event. If fep->ptp_clock is NULL, ptp_clock_event tries to dereference the NULL pointer. Since on i.MX53 fep->bufdesc_ex is not set, fec_ptp_init is never called, and fep->ptp_clock is NULL, which reliably causes a kernel panic. This patch adds a check for fep->ptp_clock == NULL in fec_enet_interrupt. Signed-off-by: Philipp Zabel --- drivers/net/ethernet/freescale/fec_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 81b96cf..50a851d 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1581,7 +1581,8 @@ fec_enet_interrupt(int irq, void *dev_id) complete(&fep->mdio_done); } - fec_ptp_check_pps_event(fep); + if (fep->ptp_clock) + fec_ptp_check_pps_event(fep); return ret; } -- 2.1.1