Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752022Ab3HTRgz (ORCPT ); Tue, 20 Aug 2013 13:36:55 -0400 Received: from shrek-wifi.podlesie.net ([93.179.225.50]:35830 "EHLO shrek.podlesie.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751599Ab3HTRgw (ORCPT ); Tue, 20 Aug 2013 13:36:52 -0400 From: Krzysztof Mazur To: linux-usb@vger.kernel.org Cc: Alan Stern , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Daniel J Blueman , Krzysztof Mazur Subject: [PATCH 2/2] usb: fail on usb_hub_create_port_device() errors Date: Tue, 20 Aug 2013 19:24:36 +0200 Message-Id: <1377019476-7701-3-git-send-email-krzysiek@podlesie.net> X-Mailer: git-send-email 1.8.4.rc1.409.gbd48715 In-Reply-To: <1377019476-7701-1-git-send-email-krzysiek@podlesie.net> References: <1377019476-7701-1-git-send-email-krzysiek@podlesie.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1748 Lines: 51 Ignoring usb_hub_create_port_device() errors cause later NULL pointer deference when uninitialized hub->ports[i] entries are dereferenced after port memory allocation error. Signed-off-by: Krzysztof Mazur --- I'm not sure if failing in that case is a good idea, but other solutions are more complex. I tried also changing hdev->maxchild and skiping initialization of later ports, but it didn't work because in some cases hub->descriptor->bNbrPorts is used instead of hdev->maxchild. With simulated usb_hub_create_port_device() failure I have an Oops in hub_power_on(). Another possible solution is allowing for uninitialized ports and checking for hub->ports[i] == NULL. drivers/usb/core/hub.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 588c3a3..afd334b 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1557,10 +1557,15 @@ static int hub_configure(struct usb_hub *hub, if (hub->has_indicators && blinkenlights) hub->indicator [0] = INDICATOR_CYCLE; - for (i = 0; i < hdev->maxchild; i++) - if (usb_hub_create_port_device(hub, i + 1) < 0) + for (i = 0; i < hdev->maxchild; i++) { + ret = usb_hub_create_port_device(hub, i + 1); + if (ret < 0) { dev_err(hub->intfdev, "couldn't create port%d device.\n", i + 1); + hdev->maxchild = i; + goto fail; + } + } usb_hub_adjust_deviceremovable(hdev, hub->descriptor); -- 1.8.4.rc1.409.gbd48715 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/