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| author | Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> | 2011-10-12 16:04:29 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-19 00:14:22 -0400 |
| commit | 4d97480b1806e883eb1c7889d4e7a87e936e06d9 (patch) | |
| tree | 0a690a2f5718826eb871ad655c9acddb5b84f335 /drivers | |
| parent | 28c213793c994e4aac5f669ce856b5682a549bbb (diff) | |
| download | lwn-4d97480b1806e883eb1c7889d4e7a87e936e06d9.tar.gz lwn-4d97480b1806e883eb1c7889d4e7a87e936e06d9.zip | |
bonding: use local function pointer of bond->recv_probe in bond_handle_frame
The bond->recv_probe is called in bond_handle_frame() when
a packet is received, but bond_close() sets it to NULL. So,
a panic occurs when both functions work in parallel.
Why this happen:
After null pointer check of bond->recv_probe, an sk_buff is
duplicated and bond->recv_probe is called in bond_handle_frame.
So, a panic occurs when bond_close() is called between the
check and call of bond->recv_probe.
Patch:
This patch uses a local function pointer of bond->recv_probe
in bond_handle_frame(). So, it can avoid the null pointer
dereference.
Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 6d79b78cfc75..de3d351ccb6b 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1435,6 +1435,8 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb) struct sk_buff *skb = *pskb; struct slave *slave; struct bonding *bond; + void (*recv_probe)(struct sk_buff *, struct bonding *, + struct slave *); skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) @@ -1448,11 +1450,12 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb) if (bond->params.arp_interval) slave->dev->last_rx = jiffies; - if (bond->recv_probe) { + recv_probe = ACCESS_ONCE(bond->recv_probe); + if (recv_probe) { struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); if (likely(nskb)) { - bond->recv_probe(nskb, bond, slave); + recv_probe(nskb, bond, slave); dev_kfree_skb(nskb); } } |