2019-11-07 16:01:02

by Ajay Singh

Subject: [PATCH] staging: wilc1000: fix illegal memory access in wilc_parse_join_bss_param()

From: Ajay Singh <[email protected]>

Do not copy the extended supported rates in 'param->supp_rates' if the
array is already full with basic rates values. The array size check
helped to avoid possible illegal memory access [1] while copying to
'param->supp_rates' array.

1. https://marc.info/?l=linux-next&m=157301720517456&w=2

Reported-by: coverity-bot <[email protected]>
Addresses-Coverity-ID: 1487400 ("Memory - illegal accesses")
Fixes: 4e0b0f42c9c7 ("staging: wilc1000: use struct to pack join parameters for FW")
Cc: [email protected]
Signed-off-by: Ajay Singh <[email protected]>
---
drivers/staging/wilc1000/hif.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/wilc1000/hif.c b/drivers/staging/wilc1000/hif.c
index 5f6706bcedf6..349e45d58ec9 100644
--- a/drivers/staging/wilc1000/hif.c
+++ b/drivers/staging/wilc1000/hif.c
@@ -485,16 +485,21 @@ void *wilc_parse_join_bss_param(struct cfg80211_bss *bss,
memcpy(&param->supp_rates[1], rates_ie + 2, rates_len);
}

- supp_rates_ie = cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES, ies->data,
- ies->len);
- if (supp_rates_ie) {
- if (supp_rates_ie[1] > (WILC_MAX_RATES_SUPPORTED - rates_len))
- param->supp_rates[0] = WILC_MAX_RATES_SUPPORTED;
- else
- param->supp_rates[0] += supp_rates_ie[1];
-
- memcpy(&param->supp_rates[rates_len + 1], supp_rates_ie + 2,
- (param->supp_rates[0] - rates_len));
+ if (rates_len < WILC_MAX_RATES_SUPPORTED) {
+ supp_rates_ie = cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES,
+ ies->data, ies->len);
+ if (supp_rates_ie) {
+ u8 ext_rates = supp_rates_ie[1];
+
+ if (ext_rates > (WILC_MAX_RATES_SUPPORTED - rates_len))
+ param->supp_rates[0] = WILC_MAX_RATES_SUPPORTED;
+ else
+ param->supp_rates[0] += ext_rates;
+
+ memcpy(&param->supp_rates[rates_len + 1],
+ supp_rates_ie + 2,
+ (param->supp_rates[0] - rates_len));
+ }
}

ht_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY, ies->data, ies->len);
--
2.22.0