From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752787AbcFEKxP (ORCPT ); Sun, 5 Jun 2016 06:53:15 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21710 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752043AbcFEKVl (ORCPT ); Sun, 5 Jun 2016 06:21:41 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yoshihiro Shimoda , stable@vger.kernel.org#v3.1+, Felipe Balbi , Willy Tarreau Subject: [PATCH 3.10 075/143] usb: renesas_usbhs: avoid NULL pointer derefernce in usbhsf_pkt_handler() Date: Sun, 5 Jun 2016 12:19:38 +0200 Message-Id: <1465122046-9645-76-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yoshihiro Shimoda commit 894f2fc44f2f3f48c36c973b1123f6ab298be160 upstream. When unexpected situation happened (e.g. tx/rx irq happened while DMAC is used), the usbhsf_pkt_handler() was possible to cause NULL pointer dereference like the followings: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 80000007 [#1] SMP ARM Modules linked in: usb_f_acm u_serial g_serial libcomposite CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.5.0-rc6-00842-gac57066-dirty #63 Hardware name: Generic R8A7790 (Flattened Device Tree) task: c0729c00 ti: c0724000 task.ti: c0724000 PC is at 0x0 LR is at usbhsf_pkt_handler+0xac/0x118 pc : [<00000000>] lr : [] psr: 60000193 sp : c0725db8 ip : 00000000 fp : c0725df4 r10: 00000001 r9 : 00000193 r8 : ef3ccab4 r7 : ef3cca10 r6 : eea4586c r5 : 00000000 r4 : ef19ceb4 r3 : 00000000 r2 : 0000009c r1 : c0725dc4 r0 : ef19ceb4 This patch adds a condition to avoid the dereference. Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support") Cc: # v3.1+ Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi Signed-off-by: Willy Tarreau --- drivers/usb/renesas_usbhs/fifo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c index 45b9401..540e688 100644 --- a/drivers/usb/renesas_usbhs/fifo.c +++ b/drivers/usb/renesas_usbhs/fifo.c @@ -166,7 +166,8 @@ static int usbhsf_pkt_handler(struct usbhs_pipe *pipe, int type) goto __usbhs_pkt_handler_end; } - ret = func(pkt, &is_done); + if (likely(func)) + ret = func(pkt, &is_done); if (is_done) __usbhsf_pkt_del(pkt); -- 2.8.0.rc2.1.gbe9624a