From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752793AbcAESHB (ORCPT ); Tue, 5 Jan 2016 13:07:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:50454 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752593AbcAERri (ORCPT ); Tue, 5 Jan 2016 12:47:38 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dan Carpenter , Kalle Valo , Jiri Slaby Subject: [PATCH 3.12 31/91] mwifiex: fix mwifiex_rdeeprom_read() Date: Tue, 5 Jan 2016 18:46:15 +0100 Message-Id: X-Mailer: git-send-email 2.6.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dan Carpenter 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 1f9c6e1bc1ba5f8a10fcd6e99d170954d7c6d382 upstream. There were several bugs here. 1) The done label was in the wrong place so we didn't copy any information out when there was no command given. 2) We were using PAGE_SIZE as the size of the buffer instead of "PAGE_SIZE - pos". 3) snprintf() returns the number of characters that would have been printed if there were enough space. If there was not enough space (and we had fixed the memory corruption bug #2) then it would result in an information leak when we do simple_read_from_buffer(). I've changed it to use scnprintf() instead. I also removed the initialization at the start of the function, because I thought it made the code a little more clear. Fixes: 5e6e3a92b9a4 ('wireless: mwifiex: initial commit for Marvell mwifiex driver') Signed-off-by: Dan Carpenter Acked-by: Amitkumar Karwar Signed-off-by: Kalle Valo Signed-off-by: Jiri Slaby --- drivers/net/wireless/mwifiex/debugfs.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/mwifiex/debugfs.c b/drivers/net/wireless/mwifiex/debugfs.c index a5f9875cfd6e..f84e5d7e8bbe 100644 --- a/drivers/net/wireless/mwifiex/debugfs.c +++ b/drivers/net/wireless/mwifiex/debugfs.c @@ -637,7 +637,7 @@ mwifiex_rdeeprom_read(struct file *file, char __user *ubuf, (struct mwifiex_private *) file->private_data; unsigned long addr = get_zeroed_page(GFP_KERNEL); char *buf = (char *) addr; - int pos = 0, ret = 0, i; + int pos, ret, i; u8 value[MAX_EEPROM_DATA]; if (!buf) @@ -645,7 +645,7 @@ mwifiex_rdeeprom_read(struct file *file, char __user *ubuf, if (saved_offset == -1) { /* No command has been given */ - pos += snprintf(buf, PAGE_SIZE, "0"); + pos = snprintf(buf, PAGE_SIZE, "0"); goto done; } @@ -654,17 +654,17 @@ mwifiex_rdeeprom_read(struct file *file, char __user *ubuf, (u16) saved_bytes, value); if (ret) { ret = -EINVAL; - goto done; + goto out_free; } - pos += snprintf(buf, PAGE_SIZE, "%d %d ", saved_offset, saved_bytes); + pos = snprintf(buf, PAGE_SIZE, "%d %d ", saved_offset, saved_bytes); for (i = 0; i < saved_bytes; i++) - pos += snprintf(buf + strlen(buf), PAGE_SIZE, "%d ", value[i]); - - ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos); + pos += scnprintf(buf + pos, PAGE_SIZE - pos, "%d ", value[i]); done: + ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos); +out_free: free_page(addr); return ret; } -- 2.6.4