From: Veaceslav Falico <vfalico@redhat•com>
To: Nikolay Aleksandrov <nikolay@redhat•com>
Cc: netdev@vger•kernel.org, davem@davemloft•net,
Jay Vosburgh <fubar@us•ibm.com>,
Andy Gospodarek <andy@greyhouse•net>
Subject: Re: [PATCH net] bonding: fix two race conditions in bond_store_updelay/downdelay
Date: Thu, 14 Nov 2013 11:17:54 +0100 [thread overview]
Message-ID: <20131114101754.GR19702@redhat.com> (raw)
In-Reply-To: <1384358866-15157-1-git-send-email-nikolay@redhat.com>
On Wed, Nov 13, 2013 at 05:07:46PM +0100, Nikolay Aleksandrov wrote:
>This patch fixes two race conditions between bond_store_updelay/downdelay
>and bond_store_miimon which could lead to division by zero as miimon can
>be set to 0 while either updelay/downdelay are being set and thus miss the
>zero check in the beginning, the zero div happens because updelay/downdelay
>are stored as new_value / bond->params.miimon. Use rtnl to synchronize with
>miimon setting.
>
>CC: Jay Vosburgh <fubar@us•ibm.com>
>CC: Andy Gospodarek <andy@greyhouse•net>
>CC: Veaceslav Falico <vfalico@redhat•com>
>Signed-off-by: Nikolay Aleksandrov <nikolay@redhat•com>
Nice, thanks! :)
Acked-by: Veaceslav Falico <vfalico@redhat•com>
>---
> drivers/net/bonding/bond_sysfs.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
>index bc8fd36..8f8a607 100644
>--- a/drivers/net/bonding/bond_sysfs.c
>+++ b/drivers/net/bonding/bond_sysfs.c
>@@ -701,6 +701,8 @@ static ssize_t bonding_store_downdelay(struct device *d,
> int new_value, ret = count;
> struct bonding *bond = to_bond(d);
>
>+ if (!rtnl_trylock())
>+ return restart_syscall();
> if (!(bond->params.miimon)) {
> pr_err("%s: Unable to set down delay as MII monitoring is disabled\n",
> bond->dev->name);
>@@ -734,6 +736,7 @@ static ssize_t bonding_store_downdelay(struct device *d,
> }
>
> out:
>+ rtnl_unlock();
> return ret;
> }
> static DEVICE_ATTR(downdelay, S_IRUGO | S_IWUSR,
>@@ -756,6 +759,8 @@ static ssize_t bonding_store_updelay(struct device *d,
> int new_value, ret = count;
> struct bonding *bond = to_bond(d);
>
>+ if (!rtnl_trylock())
>+ return restart_syscall();
> if (!(bond->params.miimon)) {
> pr_err("%s: Unable to set up delay as MII monitoring is disabled\n",
> bond->dev->name);
>@@ -789,6 +794,7 @@ static ssize_t bonding_store_updelay(struct device *d,
> }
>
> out:
>+ rtnl_unlock();
> return ret;
> }
> static DEVICE_ATTR(updelay, S_IRUGO | S_IWUSR,
>--
>1.8.1.4
>
next prev parent reply other threads:[~2013-11-14 10:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-13 16:07 [PATCH net] bonding: fix two race conditions in bond_store_updelay/downdelay Nikolay Aleksandrov
2013-11-13 16:34 ` Nikolay Aleksandrov
2013-11-13 17:03 ` Eric Dumazet
2013-11-13 17:06 ` Nikolay Aleksandrov
2013-11-13 17:38 ` Eric Dumazet
2013-11-14 1:50 ` Ding Tianhong
2013-11-14 10:17 ` Veaceslav Falico [this message]
2013-11-14 21:29 ` David Miller
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