From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752304AbcFEKWG (ORCPT ); Sun, 5 Jun 2016 06:22:06 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21747 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752118AbcFEKVv (ORCPT ); Sun, 5 Jun 2016 06:21:51 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , "David S . Miller" , Willy Tarreau Subject: [PATCH 3.10 067/143] farsync: fix off-by-one bug in fst_add_one Date: Sun, 5 Jun 2016 12:19:30 +0200 Message-Id: <1465122046-9645-68-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann commit e725a66c0202b5f36c2f9d59d26a65c53bbf21f7 upstream. gcc-6 finds an out of bounds access in the fst_add_one function when calculating the end of the mmio area: drivers/net/wan/farsync.c: In function 'fst_add_one': drivers/net/wan/farsync.c:418:53: error: index 2 denotes an offset greater than size of 'u8[2][8192] {aka unsigned char[2][8192]}' [-Werror=array-bounds] #define BUF_OFFSET(X) (BFM_BASE + offsetof(struct buf_window, X)) ^ include/linux/compiler-gcc.h:158:21: note: in definition of macro '__compiler_offsetof' __builtin_offsetof(a, b) ^ drivers/net/wan/farsync.c:418:37: note: in expansion of macro 'offsetof' #define BUF_OFFSET(X) (BFM_BASE + offsetof(struct buf_window, X)) ^~~~~~~~ drivers/net/wan/farsync.c:2519:36: note: in expansion of macro 'BUF_OFFSET' + BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER][0]); ^~~~~~~~~~ The warning is correct, but not critical because this appears to be a write-only variable that is set by each WAN driver but never accessed afterwards. I'm taking the minimal fix here, using the correct pointer by pointing 'mem_end' to the last byte inside of the register area as all other WAN drivers do, rather than the first byte outside of it. An alternative would be to just remove the mem_end member entirely. Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- drivers/net/wan/farsync.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c index bcfff0d..2dfa147 100644 --- a/drivers/net/wan/farsync.c +++ b/drivers/net/wan/farsync.c @@ -2545,7 +2545,7 @@ fst_add_one(struct pci_dev *pdev, const struct pci_device_id *ent) dev->mem_start = card->phys_mem + BUF_OFFSET ( txBuffer[i][0][0]); dev->mem_end = card->phys_mem - + BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER][0]); + + BUF_OFFSET ( txBuffer[i][NUM_TX_BUFFER - 1][LEN_RX_BUFFER - 1]); dev->base_addr = card->pci_conf; dev->irq = card->irq; -- 2.8.0.rc2.1.gbe9624a