Coverity: mt76x0_phy_get_target_power(): Memory - illegal accesses - coverity-bot

From: coverity-bot <keescook@chromium.org>
To: Felix Fietkau <nbd@nbd.name>
Cc: Lorenzo Bianconi <lorenzo@kernel.org>,
	linux-wireless@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
	Kalle Valo <kvalo@kernel.org>,
	linux-mediatek@lists.infradead.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Shayne Chen <shayne.chen@mediatek.com>,
	Eric Dumazet <edumazet@google.com>,
	"David S. Miller" <davem@davemloft.net>,
	linux-kernel@vger.kernel.org, Paolo Abeni <pabeni@redhat.com>,
	Sean Wang <sean.wang@mediatek.com>,
	linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org,
	Ryder Lee <ryder.lee@mediatek.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	linux-next@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Coverity: mt76x0_phy_get_target_power(): Memory - illegal accesses
Date: Fri, 2 Dec 2022 14:23:47 -0800	[thread overview]
Message-ID: <202212021423.5D5F1FD@keescook> (raw)

Hello!

This is an experimental semi-automated report about issues detected by
Coverity from a scan of next-20221202 as part of the linux-next scan project:
https://scan.coverity.com/projects/linux-next-weekly-scan

You're getting this email because you were associated with the identified
lines of code (noted below) that were touched by commits:

  Thu Dec 1 17:29:12 2022 +0100
    b376d96362d8 ("wifi: mt76: move mt76_rate_power from core to mt76x02 driver code")

Coverity reported the following:

*** CID 1527804:  Memory - illegal accesses  (OVERRUN)
drivers/net/wireless/mediatek/mt76/mt76x0/phy.c:645 in mt76x0_phy_get_target_power()
639     	case 4:
640     		/* vht rates */
641     		tx_rate = info[1] & 0xf;
642     		if (tx_rate > 9)
643     			return -EINVAL;
644
vvv     CID 1527804:  Memory - illegal accesses  (OVERRUN)
vvv     Overrunning array "dev->rate_power.vht" of 2 bytes at byte offset 9 using index "tx_rate" (which evaluates to 9).
645     		*target_power = cur_power + dev->rate_power.vht[tx_rate];
646     		*target_pa_power = mt76x0_phy_get_rf_pa_mode(dev, 1, tx_rate);
647     		break;
648     	default:
649     		/* ht rates */
650     		tx_rate = info[1] & 0x7f;

If this is a false positive, please let us know so we can mark it as
such, or teach the Coverity rules to be smarter. If not, please make
sure fixes get into linux-next. :) For patches fixing this, please
include these lines (but double-check the "Fixes" first):

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1527804 ("Memory - illegal accesses")
Fixes: b376d96362d8 ("wifi: mt76: move mt76_rate_power from core to mt76x02 driver code")

Thanks for your attention!

-- 
Coverity-bot