Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755112AbaDXLJV (ORCPT ); Thu, 24 Apr 2014 07:09:21 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:46533 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753863AbaDXIxZ (ORCPT ); Thu, 24 Apr 2014 04:53:25 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Yann Droneaud , Roland Dreier , Luis Henriques Subject: [PATCH 3.11 062/182] IB/nes: Return an error on ib_copy_from_udata() failure instead of NULL Date: Thu, 24 Apr 2014 09:49:47 +0100 Message-Id: <1398329507-5911-63-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398329507-5911-1-git-send-email-luis.henriques@canonical.com> References: <1398329507-5911-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Yann Droneaud commit 9d194d1025f463392feafa26ff8c2d8247f71be1 upstream. In case of error while accessing to userspace memory, function nes_create_qp() returns NULL instead of an error code wrapped through ERR_PTR(). But NULL is not expected by ib_uverbs_create_qp(), as it check for error with IS_ERR(). As page 0 is likely not mapped, it is going to trigger an Oops when the kernel will try to dereference NULL pointer to access to struct ib_qp's fields. In some rare cases, page 0 could be mapped by userspace, which could turn this bug to a vulnerability that could be exploited: the function pointers in struct ib_device will be under userspace total control. This was caught when using spatch (aka. coccinelle) to rewrite calls to ib_copy_{from,to}_udata(). Link: https://www.gitorious.org/opteya/ib-hw-nes-create-qp-null Link: https://www.gitorious.org/opteya/coccib/source/75ebf2c1033c64c1d81df13e4ae44ee99c989eba:ib_copy_udata.cocci Link: http://marc.info/?i=cover.1394485254.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud Signed-off-by: Roland Dreier Signed-off-by: Luis Henriques --- drivers/infiniband/hw/nes/nes_verbs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c index 5b53ca5..09999cd 100644 --- a/drivers/infiniband/hw/nes/nes_verbs.c +++ b/drivers/infiniband/hw/nes/nes_verbs.c @@ -1186,7 +1186,7 @@ static struct ib_qp *nes_create_qp(struct ib_pd *ibpd, nes_free_resource(nesadapter, nesadapter->allocated_qps, qp_num); kfree(nesqp->allocated_buffer); nes_debug(NES_DBG_QP, "ib_copy_from_udata() Failed \n"); - return NULL; + return ERR_PTR(-EFAULT); } if (req.user_wqe_buffers) { virt_wqs = 1; -- 1.9.1 -- 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/