Patch "ath10k: fix out of bounds access to local buffer" has been added to the 4.9-stable tree

Patch "ath10k: fix out of bounds access to local buffer" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ath10k: fix out of bounds access to local buffer

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ath10k-fix-out-of-bounds-access-to-local-buffer.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Mar 22 14:40:24 CET 2018
From: Michael Mera <dev@michaelmera.com>
Date: Mon, 24 Apr 2017 16:11:57 +0900
Subject: ath10k: fix out of bounds access to local buffer

From: Michael Mera <dev@michaelmera.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@michaelmera.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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);
 


Patches currently in stable-queue which might be from dev@michaelmera.com are

queue-4.9/ath10k-fix-out-of-bounds-access-to-local-buffer.patch