Re: [RFC PATCH net 1/2] [BUGFIX] bonding: use local function pointerof bond->recv_probe in bond_handle_frame

From: AmÃrico Wang
Date: Fri Oct 07 2011 - 09:24:55 EST


On Fri, Oct 7, 2011 at 8:49 PM, Mitsuo Hayasaka
<mitsuo.hayasaka.hu@xxxxxxxxxxx> wrote:
> 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.
>

Hmm, I don't doubt it can fix the problem, I am wondering if
bond->recv_probe should be protected by bond->lock...
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