release/5.2.40/staging-rtl8188eu-Fix-potential-security-hole.patch

From bafa3bd581a3d69610e24b75f92d69bb6b5e1bdb Mon Sep 17 00:00:00 2001
From: Larry Finger <Larry.Finger@lwfinger.net>
Date: Mon, 10 Feb 2020 12:02:30 -0600
Subject: [PATCH] staging: rtl8188eu: Fix potential security hole

commit 499c405b2b80bb3a04425ba3541d20305e014d3e upstream.

In routine rtw_hostapd_ioctl(), the user-controlled p->length is assumed
to be at least the size of struct ieee_param size, but this assumption is
never checked. This could result in out-of-bounds read/write on kernel
heap in case a p->length less than the size of struct ieee_param is
specified by the user. If p->length is allowed to be greater than the size
of the struct, then a malicious user could be wasting kernel memory.
Fixes commit a2c60d42d97c ("Add files for new driver - part 16").

Reported by: Pietro Oliva <pietroliva@gmail.com>
Cc: Pietro Oliva <pietroliva@gmail.com>
Cc: Stable <stable@vger.kernel.org>
Fixes: a2c60d42d97c ("staging: r8188eu: Add files for new driver - part 16")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Link: https://lore.kernel.org/r/20200210180235.21691-2-Larry.Finger@lwfinger.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c b/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
index 1afba937164f..b7fb13af125e 100644
--- a/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
@@ -2818,7 +2818,7 @@ static int rtw_hostapd_ioctl(struct net_device *dev, struct iw_point *p)
 		goto out;
 	}
 
-	if (!p->pointer) {
+	if (!p->pointer || p->length != sizeof(struct ieee_param)) {
 		ret = -EINVAL;
 		goto out;
 	}
-- 
2.7.4