[PATCH 4.19 33/97] staging: rtl8723bs: Fix potential security hole

Greg Kroah-Hartman
2020-02-27T14:03:56Z

From: Larry Finger <Larry.Finger@lwfinger.net>

commit ac33597c0c0d1d819dccfe001bcd0acef7107e7c 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 554c0a3abf216 ("0taging: 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 ("0taging: Add rtl8723bs sdio wifi driver").
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Link: https://lore.kernel.org/r/20200210180235.21691-3-Larry.Finger@lwfinger.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
+++ b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
@@ -4236,7 +4236,7 @@ static int rtw_hostapd_ioctl(struct net_

/* if (p->length < sizeof(struct ieee_param) || !p->pointer) { */
- if (!p->pointer) {
+ if (!p->pointer || p->length != sizeof(*param)) {
ret = -EINVAL;
goto out;
}