Re: [PATCH V2] ipv4: fix the rcu race between free_fib_info andip_route_output_slow

From: Eric Dumazet
Date: Wed May 23 2012 - 22:43:01 EST


On Thu, 2012-05-24 at 09:39 +0800, kun.jiang wrote:
> From: Yanmin Zhang <yanmin_zhang@xxxxxxxxxxxxxxx>
>
> We hit a kernel OOPS.
>
...
>
> Function free_fib_info resets nexthop_nh->nh_dev to NULL before releasing
> fi. Other cpu might be accessing fi. Fixing it by delaying the releasing.
>
> With the patch, we ran MTBF testing on Android mobile for 12 hours
> and didn't trigger the issue.
>
> Thank Eric for very detailed review/checking the issue.
>
> Signed-off-by: Yanmin Zhang <yanmin_zhang@xxxxxxxxxxxxxxx>
> Signed-off-by: Kun Jiang <kunx.jiang@xxxxxxxxx>
> ---
> net/ipv4/fib_semantics.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)

Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>

Thanks !


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