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run(4): add more length checks in Rx path.

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- Discard frames that are bigger than MCLBYTES (to prevent buffer overrun).
- Check buffer length before accessing its contents.
- Fix len <-> dmalen check - the last includes Rx Wireless information
structure size.
- Fix out-of-bounds read during Rx node search for ACK / CTS frames
(monitor mode only).

While here:
- Mark few suspicious places with comments.
- Move common cleanup to the function end.

MFC after:	1 week
This commit is contained in:
Andriy Voskoboinyk 2019-01-21 00:03:35 +00:00
parent 6baf1e4803
commit fb10d4ee38
1 changed files with 56 additions and 32 deletions
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88
sys/dev/usb/wlan/if_run.c
View File

@ -2824,69 +2824,80 @@ run_rx_frame(struct run_softc *sc, struct mbuf *m, uint32_t dmalen)
uint8_t ant, rssi;
int8_t nf;
rxwi = mtod(m, struct rt2860_rxwi *);
len = le16toh(rxwi->len) & 0xfff;
rxwisize = sizeof(struct rt2860_rxwi);
if (sc->mac_ver == 0x5592)
rxwisize += sizeof(uint64_t);
else if (sc->mac_ver == 0x3593)
rxwisize += sizeof(uint32_t);
if (__predict_false(len > dmalen)) {
m_freem(m);
counter_u64_add(ic->ic_ierrors, 1);
if (__predict_false(dmalen <
rxwisize + sizeof(struct ieee80211_frame_ack))) {
RUN_DPRINTF(sc, RUN_DEBUG_RECV,
"payload is too short: dma length %u < %zu\n",
dmalen, rxwisize + sizeof(struct ieee80211_frame_ack));
goto fail;
}
rxwi = mtod(m, struct rt2860_rxwi *);
len = le16toh(rxwi->len) & 0xfff;
if (__predict_false(len > dmalen - rxwisize)) {
RUN_DPRINTF(sc, RUN_DEBUG_RECV,
"bad RXWI length %u > %u\n", len, dmalen);
return;
goto fail;
}
/* Rx descriptor is located at the end */
rxd = (struct rt2870_rxd *)(mtod(m, caddr_t) + dmalen);
flags = le32toh(rxd->flags);
if (__predict_false(flags & (RT2860_RX_CRCERR | RT2860_RX_ICVERR))) {
m_freem(m);
counter_u64_add(ic->ic_ierrors, 1);
RUN_DPRINTF(sc, RUN_DEBUG_RECV, "%s error.\n",
(flags & RT2860_RX_CRCERR)?"CRC":"ICV");
return;
}
m->m_data += rxwisize;
m->m_pkthdr.len = m->m_len -= rxwisize;
wh = mtod(m, struct ieee80211_frame *);
if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
m->m_flags |= M_WEP;
goto fail;
}
if (flags & RT2860_RX_L2PAD) {
/*
* XXX OpenBSD removes padding between header
* and payload here...
*/
RUN_DPRINTF(sc, RUN_DEBUG_RECV,
"received RT2860_RX_L2PAD frame\n");
len += 2;
}
ni = ieee80211_find_rxnode(ic,
mtod(m, struct ieee80211_frame_min *));
m->m_data += rxwisize;
m->m_pkthdr.len = m->m_len = len;
wh = mtod(m, struct ieee80211_frame *);
/* XXX wrong for monitor mode */
if (wh->i_fc[1] & IEEE80211_FC1_PROTECTED) {
wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
m->m_flags |= M_WEP;
}
if (len >= sizeof(struct ieee80211_frame_min)) {
ni = ieee80211_find_rxnode(ic,
mtod(m, struct ieee80211_frame_min *));
} else
ni = NULL;
if (__predict_false(flags & RT2860_RX_MICERR)) {
/* report MIC failures to net80211 for TKIP */
if (ni != NULL)
ieee80211_notify_michael_failure(ni->ni_vap, wh,
rxwi->keyidx);
m_freem(m);
counter_u64_add(ic->ic_ierrors, 1);
RUN_DPRINTF(sc, RUN_DEBUG_RECV,
"MIC error. Someone is lying.\n");
return;
goto fail;
}
ant = run_maxrssi_chain(sc, rxwi);
rssi = rxwi->rssi[ant];
nf = run_rssi2dbm(sc, rssi, ant);
m->m_pkthdr.len = m->m_len = len;
if (__predict_false(ieee80211_radiotap_active(ic))) {
struct run_rx_radiotap_header *tap = &sc->sc_rxtap;
uint16_t phy;
@ -2934,6 +2945,12 @@ run_rx_frame(struct run_softc *sc, struct mbuf *m, uint32_t dmalen)
} else {
(void)ieee80211_input_all(ic, m, rssi, nf);
}
return;
fail:
m_freem(m);
counter_u64_add(ic->ic_ierrors, 1);
}
static void
@ -2943,7 +2960,7 @@ run_bulk_rx_callback(struct usb_xfer *xfer, usb_error_t error)
struct ieee80211com *ic = &sc->sc_ic;
struct mbuf *m = NULL;
struct mbuf *m0;
uint32_t dmalen;
uint32_t dmalen, mbuf_len;
uint16_t rxwisize;
int xferlen;
@ -3049,6 +3066,14 @@ run_bulk_rx_callback(struct usb_xfer *xfer, usb_error_t error)
break;
}
mbuf_len = dmalen + sizeof(struct rt2870_rxd);
if (__predict_false(mbuf_len > MCLBYTES)) {
RUN_DPRINTF(sc, RUN_DEBUG_RECV_DESC | RUN_DEBUG_USB,
"payload is too big: mbuf_len %u\n", mbuf_len);
counter_u64_add(ic->ic_ierrors, 1);
break;
}
/* copy aggregated frames to another mbuf */
m0 = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
if (__predict_false(m0 == NULL)) {
@ -3058,14 +3083,13 @@ run_bulk_rx_callback(struct usb_xfer *xfer, usb_error_t error)
break;
}
m_copydata(m, 4 /* skip 32-bit DMA-len header */,
dmalen + sizeof(struct rt2870_rxd), mtod(m0, caddr_t));
m0->m_pkthdr.len = m0->m_len =
dmalen + sizeof(struct rt2870_rxd);
mbuf_len, mtod(m0, caddr_t));
m0->m_pkthdr.len = m0->m_len = mbuf_len;
run_rx_frame(sc, m0, dmalen);
/* update data ptr */
m->m_data += dmalen + 8;
m->m_pkthdr.len = m->m_len -= dmalen + 8;
m->m_data += mbuf_len + 4;
m->m_pkthdr.len = m->m_len -= mbuf_len + 4;
}
/* make sure we free the source buffer, if any */