Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.4 06/32] bonding: fix two race conditions in bond_store_updelay/downdelay | Date | Fri, 6 Dec 2013 13:52:16 -0800 |
| |
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nikolay Aleksandrov <nikolay@redhat.com>
[ Upstream commit b869ccfab1e324507fa3596e3e1308444fb68227 ]
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.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> CC: Jay Vosburgh <fubar@us.ibm.com> CC: Andy Gospodarek <andy@greyhouse.net> CC: Veaceslav Falico <vfalico@redhat.com> Acked-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/bonding/bond_sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -693,6 +693,8 @@ static ssize_t bonding_store_downdelay(s 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); @@ -726,6 +728,7 @@ static ssize_t bonding_store_downdelay(s } out: + rtnl_unlock(); return ret; } static DEVICE_ATTR(downdelay, S_IRUGO | S_IWUSR, @@ -748,6 +751,8 @@ static ssize_t bonding_store_updelay(str 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); @@ -781,6 +786,7 @@ static ssize_t bonding_store_updelay(str } out: + rtnl_unlock(); return ret; } static DEVICE_ATTR(updelay, S_IRUGO | S_IWUSR,
| |