linux-kernel - [PATCH AUTOSEL 5.10 07/34] micrel: ksz8851: fixes struct pointer issue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221009222129.1218277-7-sashal@kernel.org>
Date:   Sun,  9 Oct 2022 18:21:01 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Jerry Ray <jerry.ray@...rochip.com>,
        "David S . Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>, edumazet@...gle.com,
        kuba@...nel.org, pabeni@...hat.com, u.kleine-koenig@...gutronix.de,
        mkl@...gutronix.de, miquel.raynal@...tlin.com, broonie@...nel.org,
        bigeasy@...utronix.de, netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 07/34] micrel: ksz8851: fixes struct pointer issue

From: Jerry Ray <jerry.ray@...rochip.com>

[ Upstream commit fef5de753ff01887cfa50990532c3890fccb9338 ]

Issue found during code review. This bug has no impact as long as the
ks8851_net structure is the first element of the ks8851_net_spi structure.
As long as the offset to the ks8851_net struct is zero, the container_of()
macro is subtracting 0 and therefore no damage done. But if the
ks8851_net_spi struct is ever modified such that the ks8851_net struct
within it is no longer the first element of the struct, then the bug would
manifest itself and cause problems.

struct ks8851_net is contained within ks8851_net_spi.
ks is contained within kss.
kss is the priv_data of the netdev structure.

Signed-off-by: Jerry Ray <jerry.ray@...rochip.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/ethernet/micrel/ks8851_spi.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/micrel/ks8851_spi.c b/drivers/net/ethernet/micrel/ks8851_spi.c
index 4ec7f1615977..8327e7f30476 100644
--- a/drivers/net/ethernet/micrel/ks8851_spi.c
+++ b/drivers/net/ethernet/micrel/ks8851_spi.c
@@ -415,7 +415,8 @@ static int ks8851_probe_spi(struct spi_device *spi)
 
 	spi->bits_per_word = 8;
 
-	ks = netdev_priv(netdev);
+	kss = netdev_priv(netdev);
+	ks = &kss->ks8851;
 
 	ks->lock = ks8851_lock_spi;
 	ks->unlock = ks8851_unlock_spi;
@@ -435,8 +436,6 @@ static int ks8851_probe_spi(struct spi_device *spi)
 		 IRQ_RXPSI)	/* RX process stop */
 	ks->rc_ier = STD_IRQ;
 
-	kss = to_ks8851_spi(ks);
-
 	kss->spidev = spi;
 	mutex_init(&kss->lock);
 	INIT_WORK(&kss->tx_work, ks8851_tx_work);
-- 
2.35.1