diff options
| author | Veaceslav Falico <vfalico@redhat.com> | 2014-02-20 12:07:57 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-02-20 13:20:55 -0500 |
| commit | 010d3c3989706d800ae72253773fa6537cc9f74c (patch) | |
| tree | bc10b84b5f84cd00b934dcb113bee0a76b87d3d9 | |
| parent | a1eabb0178bcef8eee6286bc646b66e23f4f77ea (diff) | |
bonding: fix bond_arp_rcv() race of curr_active_slave
bond->curr_active_slave can be changed between its deferences, even to
NULL, and thus we might panic.
We're always holding the rcu (rx_handler->bond_handle_frame()->bond_arp_rcv())
so fix this by rcu_dereferencing() it and using the saved.
Reported-by: Ding Tianhong <dingtianhong@huawei.com>
Fixes: aeea64a ("bonding: don't trust arp requests unless active slave really works")
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 71edf03544aa..bd70bbc7992c 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2254,6 +2254,7 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond, struct slave *slave) { struct arphdr *arp = (struct arphdr *)skb->data; + struct slave *curr_active_slave; unsigned char *arp_ptr; __be32 sip, tip; int alen, is_arp = skb->protocol == __cpu_to_be16(ETH_P_ARP); @@ -2299,6 +2300,8 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond, bond->params.arp_validate, slave_do_arp_validate(bond, slave), &sip, &tip); + curr_active_slave = rcu_dereference(bond->curr_active_slave); + /* * Backup slaves won't see the ARP reply, but do come through * here for each ARP probe (so we swap the sip/tip to validate @@ -2312,11 +2315,12 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond, * is done to avoid endless looping when we can't reach the * arp_ip_target and fool ourselves with our own arp requests. */ + if (bond_is_active_slave(slave)) bond_validate_arp(bond, slave, sip, tip); - else if (bond->curr_active_slave && - time_after(slave_last_rx(bond, bond->curr_active_slave), - bond->curr_active_slave->last_link_up)) + else if (curr_active_slave && + time_after(slave_last_rx(bond, curr_active_slave), + curr_active_slave->last_link_up)) bond_validate_arp(bond, slave, tip, sip); out_unlock: |