linux-kernel - [PATCH 4.9 131/177] ath10k: fix out of bounds access to local buffer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 23 Mar 2018 10:54:19 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Michael Mera <dev@...haelmera.com>,
        Kalle Valo <kvalo@....qualcomm.com>,
        Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH 4.9 131/177] ath10k: fix out of bounds access to local buffer

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Mera <dev@...haelmera.com>


[ Upstream commit a16703aaeaedec7a8bee5be5522c7c3e75478951 ]

During write to debugfs file simulate_fw_crash, fixed-size local buffer
'buf' is accessed and modified at index 'count-1', where 'count' is the
size of the write (so potentially out of bounds).
This patch fixes this problem.

Signed-off-by: Michael Mera <dev@...haelmera.com>
Signed-off-by: Kalle Valo <kvalo@....qualcomm.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/net/wireless/ath/ath10k/debug.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -624,17 +624,21 @@ static ssize_t ath10k_write_simulate_fw_
 					      size_t count, loff_t *ppos)
 {
 	struct ath10k *ar = file->private_data;
-	char buf[32];
+	char buf[32] = {0};
+	ssize_t rc;
 	int ret;
 
-	simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count);
+	/* filter partial writes and invalid commands */
+	if (*ppos != 0 || count >= sizeof(buf) || count == 0)
+		return -EINVAL;
 
-	/* make sure that buf is null terminated */
-	buf[sizeof(buf) - 1] = 0;
+	rc = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count);
+	if (rc < 0)
+		return rc;
 
 	/* drop the possible '\n' from the end */
-	if (buf[count - 1] == '\n')
-		buf[count - 1] = 0;
+	if (buf[*ppos - 1] == '\n')
+		buf[*ppos - 1] = '\0';
 
 	mutex_lock(&ar->conf_mutex);