Messages in this thread | | | From | Jay Vosburgh <> | Subject | Re: [PATCH net -v2] [BUGFIX] bonding: use local function pointer of bond->recv_probe in bond_handle_frame | Date | Wed, 19 Oct 2011 10:59:07 -0700 |
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David Miller <davem@davemloft.net> wrote:
>From: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> >Date: Thu, 13 Oct 2011 11:04:29 +0900 > >> 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> > >Bonding folks please review this, thanks. >
Looks reasonable. Even if by some quirk of timing the recv_probe function ends up being entered after bond_close has completed, it doesn't look like there is a risk of those functions misbehaving (because bond_close doesn't deallocate the data structures).
-J
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
--- -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com
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