Re: Possible netlink autobind regression
From: Thomas Graf
Date: Thu Sep 17 2015 - 07:48:00 EST
On 09/17/15 at 01:15pm, Herbert Xu wrote:
> On Wed, Sep 16, 2015 at 10:02:00PM -0700, Cong Wang wrote:
> >
> > This part doesn't look correct, seems it is checking if this is a kernel
> > netlink socket rather than if it is bound. But I am not sure...
>
> Good point. I've changed it so that bound is only set for non-kernel
> sockets.
>
> ---8<---
> netlink: Fix autobind race condition that leads to zero port ID
>
> The commit c0bb07df7d981e4091432754e30c9c720e2c0c78 ("netlink:
> Reset portid after netlink_insert failure") introduced a race
> condition where if two threads tried to autobind the same socket
> one of them may end up with a zero port ID.
>
> This patch reverts that commit and instead fixes it by introducing
> a separte "bound" variable to indicate whether a user-space socket
> has been bound.
>
> Fixes: c0bb07df7d98 ("netlink: Reset portid after netlink_insert failure")
> Reported-by: Tejun Heo <tj@xxxxxxxxxx>
> Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Cong Wang <cwang@xxxxxxxxxxxxxxxx>
Acked-by: Thomas Graf <tgraf@xxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/