From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934405Ab3GQWzA (ORCPT ); Wed, 17 Jul 2013 18:55:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56525 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934276Ab3GQWy4 (ORCPT ); Wed, 17 Jul 2013 18:54:56 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Dan Carpenter , "J. Bruce Fields" , Kamal Mostafa Subject: [PATCH 145/145] svcrdma: underflow issue in decode_write_list() Date: Wed, 17 Jul 2013 15:47:57 -0700 Message-Id: <1374101277-7915-146-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1374101277-7915-1-git-send-email-kamal@canonical.com> References: <1374101277-7915-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit b2781e1021525649c0b33fffd005ef219da33926 upstream. My static checker marks everything from ntohl() as untrusted and it complains we could have an underflow problem doing: return (u32 *)&ary->wc_array[nchunks]; Also on 32 bit systems the upper bound check could overflow. Signed-off-by: Dan Carpenter Signed-off-by: J. Bruce Fields Signed-off-by: Kamal Mostafa --- net/sunrpc/xprtrdma/svc_rdma_marshal.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c index 8d2eddd..65b1462 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c +++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c @@ -98,6 +98,7 @@ void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch, */ static u32 *decode_write_list(u32 *va, u32 *vaend) { + unsigned long start, end; int nchunks; struct rpcrdma_write_array *ary = @@ -113,9 +114,12 @@ static u32 *decode_write_list(u32 *va, u32 *vaend) return NULL; } nchunks = ntohl(ary->wc_nchunks); - if (((unsigned long)&ary->wc_array[0] + - (sizeof(struct rpcrdma_write_chunk) * nchunks)) > - (unsigned long)vaend) { + + start = (unsigned long)&ary->wc_array[0]; + end = (unsigned long)vaend; + if (nchunks < 0 || + nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) || + (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) { dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n", ary, nchunks, vaend); return NULL; @@ -129,6 +133,7 @@ static u32 *decode_write_list(u32 *va, u32 *vaend) static u32 *decode_reply_array(u32 *va, u32 *vaend) { + unsigned long start, end; int nchunks; struct rpcrdma_write_array *ary = (struct rpcrdma_write_array *)va; @@ -143,9 +148,12 @@ static u32 *decode_reply_array(u32 *va, u32 *vaend) return NULL; } nchunks = ntohl(ary->wc_nchunks); - if (((unsigned long)&ary->wc_array[0] + - (sizeof(struct rpcrdma_write_chunk) * nchunks)) > - (unsigned long)vaend) { + + start = (unsigned long)&ary->wc_array[0]; + end = (unsigned long)vaend; + if (nchunks < 0 || + nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) || + (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) { dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n", ary, nchunks, vaend); return NULL; -- 1.8.1.2