Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752851AbcKUFrm (ORCPT ); Mon, 21 Nov 2016 00:47:42 -0500 Received: from linuxhacker.ru ([217.76.32.60]:60366 "EHLO fiona.linuxhacker.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136AbcKUFrl (ORCPT ); Mon, 21 Nov 2016 00:47:41 -0500 From: Oleg Drokin To: Greg Kroah-Hartman , devel@driverdev.osuosl.org, Andreas Dilger , James Simmons Cc: Linux Kernel Mailing List , Lustre Development List , Jian Yu , Oleg Drokin Subject: [PATCH] staging/lustre: Use proper number of bytes in copy_from_user Date: Mon, 21 Nov 2016 00:46:48 -0500 Message-Id: <1479707208-1241688-1-git-send-email-green@linuxhacker.ru> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1324 Lines: 41 From: Jian Yu This patch removes the usage of MAX_STRING_SIZE from copy_from_user() and just copies enough bytes to cover count passed in. Signed-off-by: Jian Yu Reviewed-on: http://review.whamcloud.com/23462 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8774 Reviewed-by: John L. Hammond Signed-off-by: Oleg Drokin --- drivers/staging/lustre/lustre/obdclass/lprocfs_status.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c index 8a2f02f3..db49992 100644 --- a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c +++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c @@ -400,10 +400,17 @@ int lprocfs_wr_uint(struct file *file, const char __user *buffer, char dummy[MAX_STRING_SIZE + 1], *end; unsigned long tmp; - dummy[MAX_STRING_SIZE] = '\0'; - if (copy_from_user(dummy, buffer, MAX_STRING_SIZE)) + if (count >= sizeof(dummy)) + return -EINVAL; + + if (count == 0) + return 0; + + if (copy_from_user(dummy, buffer, count)) return -EFAULT; + dummy[count] = '\0'; + tmp = simple_strtoul(dummy, &end, 0); if (dummy == end) return -EINVAL; -- 2.7.4