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SubjectRe: [PATCH] tipc: Fix tipc_sk_reinit handling of -EAGAIN
On Wed, Aug 23, 2017 at 10:43:02AM -0400, Bob Peterson wrote:
> Hi,
>
> In 9dbbfb0ab6680c6a85609041011484e6658e7d3c function tipc_sk_reinit
> had additional logic added to loop in the event that function
> rhashtable_walk_next() returned -EAGAIN. No worries.
>
> However, if rhashtable_walk_start returns -EAGAIN, it does "continue",
> and therefore skips the call to rhashtable_walk_stop(). That has
> the effect of calling rcu_read_lock() without its paired call to
> rcu_read_unlock(). Since rcu_read_lock() may be nested, the problem
> may not be apparent for a while, especially since resize events may
> be rare. But the comments to rhashtable_walk_start() state:
>
> * ...Note that we take the RCU lock in all
> * cases including when we return an error. So you must always call
> * rhashtable_walk_stop to clean up.
>
> This patch replaces the continue with a goto and label to ensure a
> matching call to rhashtable_walk_stop().
>
> Signed-off-by: Bob Peterson <rpeterso@redhat.com>

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Thanks for catching this!
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

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