Module Name: src
Committed By: khorben
Date: Fri Dec 8 14:46:18 UTC 2017
Modified Files:
src/sys/dev/usb: usb_subr.c
Log Message:
Be more defensive towards malicious USB devices
This avoids potential panics due to 0-sized memory allocation attempts,
which could be triggered by malicious USB devices.
Tested on NetBSD/amd64 with a Sony Xperia X (SailfishOS).
Based on an initial patch by Nick Hudson <[email protected]>, thanks!
Fixes PR kern/52383.
XXX pull-up to netbsd-7, netbsd-8
LGTM xtos@
To generate a diff of this commit:
cvs rdiff -u -r1.221 -r1.222 src/sys/dev/usb/usb_subr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/usb/usb_subr.c
diff -u src/sys/dev/usb/usb_subr.c:1.221 src/sys/dev/usb/usb_subr.c:1.222
--- src/sys/dev/usb/usb_subr.c:1.221 Sat Oct 28 00:37:12 2017
+++ src/sys/dev/usb/usb_subr.c Fri Dec 8 14:46:18 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: usb_subr.c,v 1.221 2017/10/28 00:37:12 pgoyette Exp $ */
+/* $NetBSD: usb_subr.c,v 1.222 2017/12/08 14:46:18 khorben Exp $ */
/* $FreeBSD: src/sys/dev/usb/usb_subr.c,v 1.18 1999/11/17 22:33:47 n_hibma Exp $ */
/*
@@ -32,7 +32,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usb_subr.c,v 1.221 2017/10/28 00:37:12 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usb_subr.c,v 1.222 2017/12/08 14:46:18 khorben Exp $");
#ifdef _KERNEL_OPT
#include "opt_compat_netbsd.h"
@@ -609,6 +609,10 @@ usbd_set_config_index(struct usbd_device
return err;
}
len = UGETW(cd.wTotalLength);
+ if (len == 0) {
+ DPRINTF("empty short descriptor", 0, 0, 0, 0);
+ return USBD_INVAL;
+ }
cdp = kmem_alloc(len, KM_SLEEP);
/* Get the full descriptor. Try a few times for slow devices. */
@@ -635,6 +639,11 @@ usbd_set_config_index(struct usbd_device
err = usbd_get_bos_desc(dev, index, &bd);
if (!err) {
int blen = UGETW(bd.wTotalLength);
+ if (blen == 0) {
+ DPRINTF("empty bos descriptor", 0, 0, 0, 0);
+ err = USBD_INVAL;
+ goto bad;
+ }
bdp = kmem_alloc(blen, KM_SLEEP);
/* Get the full desc */
@@ -724,6 +733,11 @@ usbd_set_config_index(struct usbd_device
/* Allocate and fill interface data. */
nifc = cdp->bNumInterface;
+ if (nifc == 0) {
+ DPRINTF("no interfaces", 0, 0, 0, 0);
+ err = USBD_INVAL;
+ goto bad;
+ }
dev->ud_ifaces = kmem_alloc(nifc * sizeof(struct usbd_interface),
KM_SLEEP);
DPRINTFN(5, "dev=%#jx cdesc=%#jx", (uintptr_t)dev, (uintptr_t)cdp,
