On Wed, Apr 15, 2015 at 07:49:01PM -0700, Linus Torvalds wrote: > On Wed, Apr 15, 2015 at 7:42 PM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > > > Is CONFIG_CRYPTO_MANAGER_DISABLE_TESTS set or unset in you .config? > > # CONFIG_CRYPTO_MANAGER_DISABLE_TESTS is not set > > I'll send you the full .config in private (no need to spam the mailing > list) in case you have any other questions about my setup. Thanks! It actually appears to be a very simple bug that I somehow missed during reviewing. ---8<--- The commit 9c521a200bc3c12bd724e48a75c57d5358f672be ("crypto: api - remove instance when test failed") tried to grab a module reference count before the module was even set. Worse, it then goes on to free the module reference count after it is set so you quickly end up with a negative module reference count which prevents people from using any instances belonging to that module. This patch moves the module initialisation before the reference count. Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> diff --git a/crypto/algapi.c b/crypto/algapi.c index 2d0a1c6..d2627a3 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -525,12 +525,12 @@ int crypto_register_instance(struct crypto_template *tmpl, if (err) return err; - if (unlikely(!crypto_mod_get(&inst->alg))) - return -EAGAIN; - inst->alg.cra_module = tmpl->module; inst->alg.cra_flags |= CRYPTO_ALG_INSTANCE; + if (unlikely(!crypto_mod_get(&inst->alg))) + return -EAGAIN; + down_write(&crypto_alg_sem); larval = __crypto_register_alg(&inst->alg); -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html