Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756846AbbHDOnE (ORCPT ); Tue, 4 Aug 2015 10:43:04 -0400 Received: from mx2.suse.de ([195.135.220.15]:59437 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965241AbbHDOmz (ORCPT ); Tue, 4 Aug 2015 10:42:55 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Al Viro , Ben Hutchings , Jiri Slaby Subject: [PATCH 3.12 123/123] sg_start_req(): make sure that there's not too many elements in iovec Date: Tue, 4 Aug 2015 16:41:07 +0200 Message-Id: <34358212924d5751dc0501d44b72d5d4ef9de54c.1438699154.git.jslaby@suse.cz> X-Mailer: git-send-email 2.5.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1593 Lines: 47 From: Al Viro 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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. 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: Jiri Slaby --- drivers/scsi/sg.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index eb81c98386b9..721d839d6c54 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1694,6 +1694,9 @@ 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; -- 2.5.0 -- 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/