From 23954cb078febfc63a755301fe77e06bccdb4d2a Mon Sep 17 00:00:00 2001
From: Larry Finger <Larry.Finger@lwfinger.net>
Date: Mon, 10 Feb 2020 12:02:33 -0600
Subject: [PATCH] staging: rtl8723bs: Fix potential overuse of kernel memory
Git-commit: 23954cb078febfc63a755301fe77e06bccdb4d2a
Patch-mainline: v5.6-rc3
References: bsc#1051510

In routine wpa_supplicant_ioctl(), the user-controlled p->length is
checked to be at least the size of struct ieee_param size, but the code
does not detect the case where p->length is greater than the size
of the struct, thus a malicious user could be wasting kernel memory.
Fixes commit 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver").

Reported by: Pietro Oliva <pietroliva@gmail.com>

Cc: Pietro Oliva <pietroliva@gmail.com>
Cc: Stable <stable@vger.kernel.org>
Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver").
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Link: https://lore.kernel.org/r/20200210180235.21691-5-Larry.Finger@lwfinger.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/rtl8723bs/os_dep/ioctl_linux.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
index 3128766dd50e..2ac0d84f090e 100644
--- a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
+++ b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
@@ -3373,7 +3373,7 @@ static int wpa_supplicant_ioctl(struct net_device *dev, struct iw_point *p)
 
 	/* down(&ieee->wx_sem); */
 
-	if (p->length < sizeof(struct ieee_param) || !p->pointer) {
+	if (!p->pointer || p->length != sizeof(struct ieee_param)) {
 		ret = -EINVAL;
 		goto out;
 	}
-- 
2.16.4