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Date:      Thu, 11 Jun 2020 14:31:51 +0000 (UTC)
From:      Hans Petter Selasky <hselasky@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r362056 - head/sys/dev/usb/net
Message-ID:  <202006111431.05BEVpb9015286@repo.freebsd.org>
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Author: hselasky
Date: Thu Jun 11 14:31:51 2020
New Revision: 362056
URL: https://svnweb.freebsd.org/changeset/base/362056

Log:
  Add missing range checks when receiving USB ethernet packets.
  
  Found by:	Ilja Van Sprundel, IOActive
  MFC after:	3 days
  Sponsored by:	Mellanox Technologies

Modified:
  head/sys/dev/usb/net/if_cdceem.c
  head/sys/dev/usb/net/if_muge.c
  head/sys/dev/usb/net/if_smsc.c

Modified: head/sys/dev/usb/net/if_cdceem.c
==============================================================================
--- head/sys/dev/usb/net/if_cdceem.c	Thu Jun 11 14:09:43 2020	(r362055)
+++ head/sys/dev/usb/net/if_cdceem.c	Thu Jun 11 14:31:51 2020	(r362056)
@@ -427,9 +427,10 @@ cdceem_handle_data(struct usb_xfer *xfer, uint16_t hdr
 	struct usb_ether *ue;
 	struct ifnet *ifp;
 	struct mbuf *m;
-	int actlen, off;
 	uint32_t computed_crc, received_crc;
-	uint16_t pktlen;
+	int pktlen;
+	int actlen;
+	int off;
 
 	off = *offp;
 	sc = usbd_xfer_softc(xfer);
@@ -443,7 +444,7 @@ cdceem_handle_data(struct usb_xfer *xfer, uint16_t hdr
 	    (hdr & CDCEEM_DATA_CRC) ? "valid" : "absent",
 	    pktlen);
 
-	if (pktlen < ETHER_HDR_LEN) {
+	if (pktlen < (ETHER_HDR_LEN + 4)) {
 		CDCEEM_WARN(sc,
 		    "bad ethernet frame length %d, should be at least %d",
 		    pktlen, ETHER_HDR_LEN);
@@ -467,6 +468,14 @@ cdceem_handle_data(struct usb_xfer *xfer, uint16_t hdr
 	}
 
 	pktlen -= 4; /* Subtract the CRC. */
+
+	if (pktlen > m->m_len) {
+		CDCEEM_WARN(sc, "buffer too small %d vs %d bytes",
+		    pktlen, m->m_len);
+		if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
+		m_freem(m);
+		return;
+	}
 	usbd_copy_out(pc, off, mtod(m, uint8_t *), pktlen);
 	off += pktlen;
 
@@ -513,7 +522,7 @@ cdceem_bulk_read_callback(struct usb_xfer *xfer, usb_e
 		pc = usbd_xfer_get_frame(xfer, 0);
 		off = 0;
 
-		while (off < actlen) {
+		while ((off + sizeof(hdr)) <= actlen) {
 			usbd_copy_out(pc, off, &hdr, sizeof(hdr));
 			CDCEEM_DEBUG(sc, "hdr = %#x", hdr);
 			off += sizeof(hdr);

Modified: head/sys/dev/usb/net/if_muge.c
==============================================================================
--- head/sys/dev/usb/net/if_muge.c	Thu Jun 11 14:09:43 2020	(r362055)
+++ head/sys/dev/usb/net/if_muge.c	Thu Jun 11 14:31:51 2020	(r362056)
@@ -1169,9 +1169,9 @@ muge_bulk_read_callback(struct usb_xfer *xfer, usb_err
 	struct ifnet *ifp = uether_getifp(ue);
 	struct mbuf *m;
 	struct usb_page_cache *pc;
-	uint16_t pktlen;
 	uint32_t rx_cmd_a, rx_cmd_b;
 	uint16_t rx_cmd_c;
+	int pktlen;
 	int off;
 	int actlen;
 
@@ -1249,7 +1249,14 @@ muge_bulk_read_callback(struct usb_xfer *xfer, usb_err
 					    1);
 					goto tr_setup;
 				}
-
+				if (pktlen > m->m_len) {
+					muge_dbg_printf(sc,
+					    "buffer too small %d vs %d bytes",
+					    pktlen, m->m_len);
+					if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
+					m_freem(m);
+					goto tr_setup;
+				}
 				usbd_copy_out(pc, off, mtod(m, uint8_t *),
 				    pktlen);
 

Modified: head/sys/dev/usb/net/if_smsc.c
==============================================================================
--- head/sys/dev/usb/net/if_smsc.c	Thu Jun 11 14:09:43 2020	(r362055)
+++ head/sys/dev/usb/net/if_smsc.c	Thu Jun 11 14:31:51 2020	(r362056)
@@ -955,7 +955,7 @@ smsc_bulk_read_callback(struct usb_xfer *xfer, usb_err
 	struct mbuf *m;
 	struct usb_page_cache *pc;
 	uint32_t rxhdr;
-	uint16_t pktlen;
+	int pktlen;
 	int off;
 	int actlen;
 
@@ -981,6 +981,9 @@ smsc_bulk_read_callback(struct usb_xfer *xfer, usb_err
 			/* The frame header is always aligned on a 4 byte boundary */
 			off = ((off + 0x3) & ~0x3);
 
+			if ((off + sizeof(rxhdr)) > actlen)
+				goto tr_setup;
+
 			usbd_copy_out(pc, off, &rxhdr, sizeof(rxhdr));
 			off += (sizeof(rxhdr) + ETHER_ALIGN);
 			rxhdr = le32toh(rxhdr);
@@ -1009,7 +1012,13 @@ smsc_bulk_read_callback(struct usb_xfer *xfer, usb_err
 					if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
 					goto tr_setup;
 				}
-				
+				if (pktlen > m->m_len) {
+					smsc_dbg_printf(sc, "buffer too small %d vs %d bytes",
+					    pktlen, m->m_len);
+					if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
+					m_freem(m);
+					goto tr_setup;
+				}
 				usbd_copy_out(pc, off, mtod(m, uint8_t *), pktlen);
 
 				/* Check if RX TCP/UDP checksumming is being offloaded */

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