From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Mera , Leon Romanovsky , Doug Ledford , Amit Pundir Subject: [PATCH 4.9 021/107] IB/ocrdma: fix out of bounds access to local buffer Date: Tue, 14 Aug 2018 19:16:44 +0200 Message-Id: <20180814171521.977814800@linuxfoundation.org> In-Reply-To: <20180814171520.883143803@linuxfoundation.org> References: <20180814171520.883143803@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Mera commit 062d0f22a30c39840ea49b72cfcfc1aa4cc538fa upstream. In write to debugfs file 'resource_stats' the local buffer 'tmp_str' is written at index 'count-1' where 'count' is the size of the write, so potentially 0. This patch filters odd values for the write size/position to avoid this type of problem. Signed-off-by: Michael Mera Reviewed-by: Leon Romanovsky Signed-off-by: Doug Ledford Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/ocrdma/ocrdma_stats.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/infiniband/hw/ocrdma/ocrdma_stats.c +++ b/drivers/infiniband/hw/ocrdma/ocrdma_stats.c @@ -645,7 +645,7 @@ static ssize_t ocrdma_dbgfs_ops_write(st struct ocrdma_stats *pstats = filp->private_data; struct ocrdma_dev *dev = pstats->dev; - if (count > 32) + if (*ppos != 0 || count == 0 || count > sizeof(tmp_str)) goto err; if (copy_from_user(tmp_str, buffer, count))