netdev - [PATCH AUTOSEL 4.9 15/18] net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts

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>] [day] [month] [year] [list]

Message-Id: <20181129060331.160224-15-sashal@kernel.org>
Date:   Thu, 29 Nov 2018 01:03:27 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     stable@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Vincent Chen <vincentc@...estech.com>,
        "David S . Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>, netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 4.9 15/18] net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts

From: Vincent Chen <vincentc@...estech.com>

[ Upstream commit 426a593e641ebf0d9288f0a2fcab644a86820220 ]

In the original ftmac100_interrupt(), the interrupts are only disabled when
the condition "netif_running(netdev)" is true. However, this condition
causes kerenl hang in the following case. When the user requests to
disable the network device, kernel will clear the bit __LINK_STATE_START
from the dev->state and then call the driver's ndo_stop function. Network
device interrupts are not blocked during this process. If an interrupt
occurs between clearing __LINK_STATE_START and stopping network device,
kernel cannot disable the interrupts due to the condition
"netif_running(netdev)" in the ISR. Hence, kernel will hang due to the
continuous interruption of the network device.

In order to solve the above problem, the interrupts of the network device
should always be disabled in the ISR without being restricted by the
condition "netif_running(netdev)".

[V2]
Remove unnecessary curly braces.

Signed-off-by: Vincent Chen <vincentc@...estech.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/ethernet/faraday/ftmac100.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/faraday/ftmac100.c b/drivers/net/ethernet/faraday/ftmac100.c
index dce5f7b7f772..05e1f923f49e 100644
--- a/drivers/net/ethernet/faraday/ftmac100.c
+++ b/drivers/net/ethernet/faraday/ftmac100.c
@@ -865,11 +865,10 @@ static irqreturn_t ftmac100_interrupt(int irq, void *dev_id)
 	struct net_device *netdev = dev_id;
 	struct ftmac100 *priv = netdev_priv(netdev);

-	if (likely(netif_running(netdev))) {
-		/* Disable interrupts for polling */
-		ftmac100_disable_all_int(priv);
+	/* Disable interrupts for polling */
+	ftmac100_disable_all_int(priv);
+	if (likely(netif_running(netdev)))
 		napi_schedule(&priv->napi);
-	}

 	return IRQ_HANDLED;
 }
-- 
2.17.1