From: Denis Efremov <efremov@linux.com>
Date: Mon, 30 Sep 2019 20:31:47 +0000 (+0300)
Subject: ar5523: check NULL before memcpy() in ar5523_cmd()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e5e7acb11772315b28b2c20afa97e37941330eaa;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

ar5523: check NULL before memcpy() in ar5523_cmd()

commit 315cee426f87658a6799815845788fde965ddaad upstream.

memcpy() call with "idata == NULL && ilen == 0" results in undefined
behavior in ar5523_cmd(). For example, NULL is passed in callchain
"ar5523_stat_work() -> ar5523_cmd_write() -> ar5523_cmd()". This patch
adds ilen check before memcpy() call in ar5523_cmd() to prevent an
undefined behavior.

Cc: Pontus Fuchs <pontus.fuchs@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: stable@vger.kernel.org
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index 7a60d2e652da..e492c7f0d311 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.c
+++ b/drivers/net/wireless/ath/ar5523/ar5523.c
@@ -255,7 +255,8 @@ static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata,
 
 	if (flags & AR5523_CMD_FLAG_MAGIC)
 		hdr->magic = cpu_to_be32(1 << 24);
-	memcpy(hdr + 1, idata, ilen);
+	if (ilen)
+		memcpy(hdr + 1, idata, ilen);
 
 	cmd->odata = odata;
 	cmd->olen = olen;