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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2015-12-30 11:47:53 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-19 14:22:41 -0800 |
| commit | 5a707f0972e1c9d8a4a921ddae79d0f9dc36a341 (patch) | |
| tree | f369016f1ea124caa978416ed9151dc17220903a /include | |
| parent | 766ac2a01cbbb7762f88127c32bcd9697c97f060 (diff) | |
| download | lwn-5a707f0972e1c9d8a4a921ddae79d0f9dc36a341.tar.gz lwn-5a707f0972e1c9d8a4a921ddae79d0f9dc36a341.zip | |
crypto: af_alg - Disallow bind/setkey/... after accept(2)
commit c840ac6af3f8713a71b4d2363419145760bd6044 upstream.
Each af_alg parent socket obtained by socket(2) corresponds to a
tfm object once bind(2) has succeeded. An accept(2) call on that
parent socket creates a context which then uses the tfm object.
Therefore as long as any child sockets created by accept(2) exist
the parent socket must not be modified or freed.
This patch guarantees this by using locks and a reference count
on the parent socket. Any attempt to modify the parent socket will
fail with EBUSY.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/crypto/if_alg.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index d61c11170213..2f38daaab3d7 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -30,6 +30,8 @@ struct alg_sock { struct sock *parent; + unsigned int refcnt; + const struct af_alg_type *type; void *private; }; @@ -64,6 +66,7 @@ int af_alg_register_type(const struct af_alg_type *type); int af_alg_unregister_type(const struct af_alg_type *type); int af_alg_release(struct socket *sock); +void af_alg_release_parent(struct sock *sk); int af_alg_accept(struct sock *sk, struct socket *newsock); int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len, @@ -80,11 +83,6 @@ static inline struct alg_sock *alg_sk(struct sock *sk) return (struct alg_sock *)sk; } -static inline void af_alg_release_parent(struct sock *sk) -{ - sock_put(alg_sk(sk)->parent); -} - static inline void af_alg_init_completion(struct af_alg_completion *completion) { init_completion(&completion->completion); |