Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753701AbcDZUmr (ORCPT ); Tue, 26 Apr 2016 16:42:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:58212 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753340AbcDZUZX (ORCPT ); Tue, 26 Apr 2016 16:25:23 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Arnd Bergmann , "David S . Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 12/66] farsync: fix off-by-one bug in fst_add_one Date: Tue, 26 Apr 2016 13:24:03 -0700 Message-Id: <1461702297-7792-13-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1461702297-7792-1-git-send-email-kamal@canonical.com> References: <1461702297-7792-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2593 Lines: 57 3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Arnd Bergmann [ Upstream commit e725a66c0202b5f36c2f9d59d26a65c53bbf21f7 ] 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: Kamal Mostafa --- 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 44541dbc..69b994f 100644 --- a/drivers/net/wan/farsync.c +++ b/drivers/net/wan/farsync.c @@ -2516,7 +2516,7 @@ 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; -- 2.7.4