[PATCH AUTOSEL 5.0 074/317] mwifiex: prevent an array overflow

Sasha Levin
2019-05-22T19:54:02Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit b4c35c17227fe437ded17ce683a6927845f8c4a4 ]

The "rate_index" is only used as an index into the phist_data->rx_rate[]
array in the mwifiex_hist_data_set() function. That array has
MWIFIEX_MAX_AC_RX_RATES (74) elements and it's used to generate some
debugfs information. The "rate_index" variable comes from the network
skb->data[] and it is a u8 so it's in the 0-255 range. We need to cap
it to prevent an array overflow.

Fixes: cbf6e05527a7 ("mwifiex: add rx histogram statistics support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/marvell/mwifiex/cfp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/cfp.c b/drivers/net/wireless/marvell/mwifiex/cfp.c
index bfe84e55df776..f1522fb1c1e87 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfp.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfp.c
@@ -531,5 +531,8 @@ u8 mwifiex_adjust_data_rate(struct mwifiex_private *priv,
rate_index = (rx_rate > MWIFIEX_RATE_INDEX_OFDM0) ?
rx_rate - 1 : rx_rate;

+ if (rate_index >= MWIFIEX_MAX_AC_RX_RATES)
+ rate_index = MWIFIEX_MAX_AC_RX_RATES - 1;
+
return rate_index;
}
--
2.20.1