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net80211: provide rate validation for injected frames.

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There may be various side effects (device timeout, firmware and / or
kernel panic) when an invalid (or inapplicable - e.g., an MCS rate
for 11g-only device) is set; check rates before sending the frame to
the driver.

How-to-reproduce:
Set an MCS (real or bogus - with 0x80 bit set) rate in ibp_rate0 field
for any device that uses ieee80211_isratevalid() for rate checks -
rum(4), run(4), ural(4), bwi(4) or ral(4); if kernel is compiled
with INVARIANTS the check will result in "rate %d is basic/mcs?" panic.

Tested with WUSB54GC (rum(4)), AP mode.

MFC after:	1 week
This commit is contained in:
Andriy Voskoboinyk 2019-01-13 06:01:36 +00:00
parent b9dee1ff02
commit e42e878b35
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=342991
1 changed files with 95 additions and 0 deletions
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95
sys/net80211/ieee80211_output.c
View File

@ -604,6 +604,97 @@ ieee80211_validate_frame(struct mbuf *m,
return (0);
}
static int
ieee80211_validate_rate(struct ieee80211_node *ni, uint8_t rate)
{
struct ieee80211com *ic = ni->ni_ic;
if (IEEE80211_IS_HT_RATE(rate)) {
if ((ic->ic_htcaps & IEEE80211_HTC_HT) == 0)
return (EINVAL);
rate = IEEE80211_RV(rate);
if (rate <= 31) {
if (rate > ic->ic_txstream * 8 - 1)
return (EINVAL);
return (0);
}
if (rate == 32) {
if ((ic->ic_htcaps & IEEE80211_HTC_TXMCS32) == 0)
return (EINVAL);
return (0);
}
if ((ic->ic_htcaps & IEEE80211_HTC_TXUNEQUAL) == 0)
return (EINVAL);
switch (ic->ic_txstream) {
case 0:
case 1:
return (EINVAL);
case 2:
if (rate > 38)
return (EINVAL);
return (0);
case 3:
if (rate > 52)
return (EINVAL);
return (0);
case 4:
default:
if (rate > 76)
return (EINVAL);
return (0);
}
}
if (!ieee80211_isratevalid(ic->ic_rt, rate))
return (EINVAL);
return (0);
}
static int
ieee80211_sanitize_rates(struct ieee80211_node *ni, struct mbuf *m,
const struct ieee80211_bpf_params *params)
{
int error;
if (!params)
return (0); /* nothing to do */
/* NB: most drivers assume that ibp_rate0 is set (!= 0). */
if (params->ibp_rate0 != 0) {
error = ieee80211_validate_rate(ni, params->ibp_rate0);
if (error != 0)
return (error);
} else {
/* XXX pre-setup some default (e.g., mgmt / mcast) rate */
/* XXX __DECONST? */
(void) m;
}
if (params->ibp_rate1 != 0 &&
(error = ieee80211_validate_rate(ni, params->ibp_rate1)) != 0)
return (error);
if (params->ibp_rate2 != 0 &&
(error = ieee80211_validate_rate(ni, params->ibp_rate2)) != 0)
return (error);
if (params->ibp_rate3 != 0 &&
(error = ieee80211_validate_rate(ni, params->ibp_rate3)) != 0)
return (error);
return (0);
}
/*
* 802.11 output routine. This is (currently) used only to
* connect bpf write calls to the 802.11 layer for injecting
@ -718,6 +809,10 @@ ieee80211_output(struct ifnet *ifp, struct mbuf *m,
} else
M_WME_SETAC(m, WME_AC_BE);
error = ieee80211_sanitize_rates(ni, m, params);
if (error != 0)
senderr(error);
IEEE80211_NODE_STAT(ni, tx_data);
if (IEEE80211_IS_MULTICAST(wh->i_addr1)) {
IEEE80211_NODE_STAT(ni, tx_mcast);