Coverity: mt7996_rf_regval_set(): Integer handling issues - coverity-bot

From: coverity-bot <keescook@chromium.org>
To: Shayne Chen <shayne.chen@mediatek.com>
Cc: Lorenzo Bianconi <lorenzo@kernel.org>,
	linux-wireless@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
	Kalle Valo <kvalo@kernel.org>,
	StanleyYP Wang <StanleyYP.Wang@mediatek.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Peter Chiu <chui-hao.chiu@mediatek.com>,
	Eric Dumazet <edumazet@google.com>,
	Money Wang <Money.Wang@mediatek.com>,
	linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org,
	Howard Hsu <howard-yh.hsu@mediatek.com>,
	linux-mediatek@lists.infradead.org, Felix Fietkau <nbd@nbd.name>,
	"David S. Miller" <davem@davemloft.net>,
	Evelyn Tsai <evelyn.tsai@mediatek.com>,
	linux-kernel@vger.kernel.org,
	MeiChia Chiu <meichia.chiu@mediatek.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Sean Wang <sean.wang@mediatek.com>,
	Bo Jiao <Bo.Jiao@mediatek.com>,
	Ryder Lee <ryder.lee@mediatek.com>,
	Sujuan Chen <sujuan.chen@mediatek.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	linux-next@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Coverity: mt7996_rf_regval_set(): Integer handling issues
Date: Fri, 2 Dec 2022 14:05:43 -0800	[thread overview]
Message-ID: <202212021405.93CF11D2A@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 17:29:14 2022 +0100
    98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")

Coverity reported the following:

*** CID 1527816:  Integer handling issues  (INCOMPATIBLE_CAST)
drivers/net/wireless/mediatek/mt76/mt7996/debugfs.c:657 in mt7996_rf_regval_set()
651
652     static int
653     mt7996_rf_regval_set(void *data, u64 val)
654     {
655     	struct mt7996_dev *dev = data;
656
vvv     CID 1527816:  Integer handling issues  (INCOMPATIBLE_CAST)
vvv     Pointer "&val" points to an object whose effective type is "unsigned long long" (64 bits, unsigned) but is dereferenced as a narrower "unsigned int" (32 bits, unsigned). This may lead to unexpected results depending on machine endianness.
657     	return mt7996_mcu_rf_regval(dev, dev->mt76.debugfs_reg, (u32 *)&val, true);
658     }
659
660     DEFINE_DEBUGFS_ATTRIBUTE(fops_rf_regval, mt7996_rf_regval_get,
661     			 mt7996_rf_regval_set, "0x%08llx\n");
662

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: 1527816 ("Integer handling issues")
Fixes: 98686cd21624 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")

Thanks for your attention!

-- 
Coverity-bot