| From 528dfe7694081afbdd4e7738b93bd9e25780ed1b Mon Sep 17 00:00:00 2001 |
| From: Nikolay Aleksandrov <nikolay@redhat.com> |
| Date: Wed, 13 Nov 2013 17:07:46 +0100 |
| Subject: bonding: fix two race conditions in bond_store_updelay/downdelay |
| |
| 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 |
| @@ -697,6 +697,8 @@ 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); |
| @@ -730,6 +732,7 @@ static ssize_t bonding_store_downdelay(s |
| } |
| |
| out: |
| + rtnl_unlock(); |
| return ret; |
| } |
| static DEVICE_ATTR(downdelay, S_IRUGO | S_IWUSR, |
| @@ -752,6 +755,8 @@ 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); |
| @@ -785,6 +790,7 @@ static ssize_t bonding_store_updelay(str |
| } |
| |
| out: |
| + rtnl_unlock(); |
| return ret; |
| } |
| static DEVICE_ATTR(updelay, S_IRUGO | S_IWUSR, |
