Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934571AbbHLJVD (ORCPT ); Wed, 12 Aug 2015 05:21:03 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:60819 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934455AbbHLI6N (ORCPT ); Wed, 12 Aug 2015 04:58:13 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Al Viro , Ben Hutchings , Luis Henriques Subject: [PATCH 3.16.y-ckt 073/118] sg_start_req(): make sure that there's not too many elements in iovec Date: Wed, 12 Aug 2015 09:56:15 +0100 Message-Id: <1439369820-27005-74-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> References: <1439369820-27005-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1666 Lines: 45 3.16.7-ckt16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit 451a2886b6bf90e2fb378f7c46c655450fb96e81 upstream. unfortunately, allowing an arbitrary 16bit value means a possibility of overflow in the calculation of total number of pages in bio_map_user_iov() - we rely on there being no more than PAGE_SIZE members of sum in the first loop there. If that sum wraps around, we end up allocating too small array of pointers to pages and it's easy to overflow it in the second loop. X-Coverup: TINC (and there's no lumber cartel either) Signed-off-by: Al Viro [bwh: s/MAX_UIOVEC/UIO_MAXIOV/. This was fixed upstream by commit fdc81f45e9f5 ("sg_start_req(): use import_iovec()"), but we don't have that function.] Signed-off-by: Ben Hutchings Signed-off-by: Luis Henriques --- drivers/scsi/sg.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 791460b798f4..2aa95c89b5bf 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1693,6 +1693,9 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd) md->from_user = 0; } + if (unlikely(iov_count > UIO_MAXIOV)) + return -EINVAL; + if (iov_count) { int len, size = sizeof(struct sg_iovec) * iov_count; struct iovec *iov; -- 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/