From b8e15992b420d09dae831125a623c474c8637cee Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 28 Jan 2009 14:09:59 +1100 Subject: [PATCH] crypto: api - Fix algorithm test race that broke aead initialisation When we complete a test we'll notify everyone waiting on it, drop the mutex, and then remove the test larval (after reacquiring the mutex). If one of the notified parties tries to register another algorithm with the same driver name prior to the removal of the test larval, they will fail with EEXIST as only one algorithm of a given name can be tested at any time. This broke the initialisation of aead and givcipher algorithms as they will register two algorithms with the same driver name, in sequence. This patch fixes the problem by marking the larval as dead before we drop the mutex, and also ignoring all dead or dying algorithms on the registration path. Tested-by: Andreas Steffen Signed-off-by: Herbert Xu --- crypto/algapi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index 7c41e7405c4..56c62e2858d 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -149,6 +149,9 @@ static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg) if (q == alg) goto err; + if (crypto_is_moribund(q)) + continue; + if (crypto_is_larval(q)) { if (!strcmp(alg->cra_driver_name, q->cra_driver_name)) goto err; @@ -197,7 +200,7 @@ void crypto_alg_tested(const char *name, int err) down_write(&crypto_alg_sem); list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (!crypto_is_larval(q)) + if (crypto_is_moribund(q) || !crypto_is_larval(q)) continue; test = (struct crypto_larval *)q; @@ -210,6 +213,7 @@ void crypto_alg_tested(const char *name, int err) goto unlock; found: + q->cra_flags |= CRYPTO_ALG_DEAD; alg = test->adult; if (err || list_empty(&alg->cra_list)) goto complete;