Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964931AbdCJMYB (ORCPT ); Fri, 10 Mar 2017 07:24:01 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45281 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935204AbdCJMX7 (ORCPT ); Fri, 10 Mar 2017 07:23:59 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alan Stern" , "Felipe Balbi" , "Andrey Konovalov" Date: Fri, 10 Mar 2017 11:46:22 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 139/370] USB: dummy-hcd: fix bug in stop_activity (handle ep0) In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2848 Lines: 66 3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit bcdbeb844773333d2d1c08004f3b3e25921040e5 upstream. The stop_activity() routine in dummy-hcd is supposed to unlink all active requests for every endpoint, among other things. But it doesn't handle ep0. As a result, fuzz testing can generate a WARNING like the following: WARNING: CPU: 0 PID: 4410 at drivers/usb/gadget/udc/dummy_hcd.c:672 dummy_free_request+0x153/0x170 Modules linked in: CPU: 0 PID: 4410 Comm: syz-executor Not tainted 4.9.0-rc7+ #32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff88006a64ed10 ffffffff81f96b8a ffffffff41b58ab3 1ffff1000d4c9d35 ffffed000d4c9d2d ffff880065f8ac00 0000000041b58ab3 ffffffff8598b510 ffffffff81f968f8 0000000041b58ab3 ffffffff859410e0 ffffffff813f0590 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x292/0x398 lib/dump_stack.c:51 [] __warn+0x19f/0x1e0 kernel/panic.c:550 [] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [] dummy_free_request+0x153/0x170 drivers/usb/gadget/udc/dummy_hcd.c:672 [] usb_ep_free_request+0xc0/0x420 drivers/usb/gadget/udc/core.c:195 [] gadgetfs_unbind+0x131/0x190 drivers/usb/gadget/legacy/inode.c:1612 [] usb_gadget_remove_driver+0x10f/0x2b0 drivers/usb/gadget/udc/core.c:1228 [] usb_gadget_unregister_driver+0x154/0x240 drivers/usb/gadget/udc/core.c:1357 This patch fixes the problem by iterating over all the endpoints in the driver's ep array instead of iterating over the gadget's ep_list, which explicitly leaves out ep0. Signed-off-by: Alan Stern Reported-by: Andrey Konovalov Signed-off-by: Felipe Balbi [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- drivers/usb/gadget/dummy_hcd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/usb/gadget/dummy_hcd.c +++ b/drivers/usb/gadget/dummy_hcd.c @@ -266,7 +266,7 @@ static void nuke(struct dummy *dum, stru /* caller must hold lock */ static void stop_activity(struct dummy *dum) { - struct dummy_ep *ep; + int i; /* prevent any more requests */ dum->address = 0; @@ -274,8 +274,8 @@ static void stop_activity(struct dummy * /* The timer is left running so that outstanding URBs can fail */ /* nuke any pending requests first, so driver i/o is quiesced */ - list_for_each_entry(ep, &dum->gadget.ep_list, ep.ep_list) - nuke(dum, ep); + for (i = 0; i < DUMMY_ENDPOINTS; ++i) + nuke(dum, &dum->ep[i]); /* driver now does any non-usb quiescing necessary */ }