From 39c69f64011fb9e11ae0d6b638455a463a489358 Mon Sep 17 00:00:00 2001 From: Denis Efremov Date: Wed, 18 Dec 2019 14:31:32 +0800 Subject: [PATCH] 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 Cc: Kalle Valo Cc: "David S. Miller" Cc: David Laight Cc: stable@vger.kernel.org Signed-off-by: Denis Efremov Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- drivers/net/wireless/ath/ar5523/ar5523.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c index b94759daeacc..da2d179430ca 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; -- GitLab