netdev - [PATCH] davinci_mdio: Fix MDIO timeout check

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-next>] [day] [month] [year] [list]

Date:	Mon, 16 Apr 2012 16:35:25 +0200
From:	Christian Riesch <christian.riesch@...cron.at>
To:	<netdev@...r.kernel.org>
CC:	<davinci-linux-open-source@...ux.davincidsp.com>,
	<ravonereal@...il.com>,
	Manfred Rudigier <manfred.rudigier@...cron.at>,
	Christian Riesch <christian.riesch@...cron.at>,
	<stable@...r.kernel.org>, Cyril Chemparathy <cyril@...com>
Subject: [PATCH] davinci_mdio: Fix MDIO timeout check

Under heavy load (flood ping) it is possible for the MDIO timeout to
expire before the loop checks the GO bit again. This patch adds an
additional check whether the operation was done before actually
returning -ETIMEDOUT.

To reproduce this bug, flood ping the device, e.g., ping -f -l 1000
After some time, a "timed out waiting for user access" warning
may appear. And even worse, link may go down since the PHY reported a
timeout.

Signed-off-by: Christian Riesch <christian.riesch@...cron.at>
Cc: <stable@...r.kernel.org>
Cc: Cyril Chemparathy <cyril@...com>
---
 drivers/net/ethernet/ti/davinci_mdio.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 2757c7d..e4e4708 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -181,6 +181,11 @@ static inline int wait_for_user_access(struct davinci_mdio_data *data)
 		__davinci_mdio_reset(data);
 		return -EAGAIN;
 	}
+
+	reg = __raw_readl(&regs->user[0].access);
+	if ((reg & USERACCESS_GO) == 0)
+		return 0;
+
 	dev_err(data->dev, "timed out waiting for user access\n");
 	return -ETIMEDOUT;
 }
-- 
1.7.0.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html