* [PATCH] crypto: api - Check spawn->alg under lock in crypto_drop_spawn
@ 2019-12-06 5:55 Herbert Xu
2019-12-11 3:36 ` Eric Biggers
0 siblings, 1 reply; 3+ messages in thread
From: Herbert Xu @ 2019-12-06 5:55 UTC (permalink / raw)
To: Linux Crypto Mailing List
We need to check whether spawn->alg is NULL under lock as otherwise
the algorithm could be removed from under us after we have checked
it and found it to be non-NULL. This could cause us to remove the
spawn from a non-existent list.
Fixes: 6bfd48096ff8 ("[CRYPTO] api: Added spawns")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 783006f4d339..6869feb31c99 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -668,11 +668,9 @@ EXPORT_SYMBOL_GPL(crypto_grab_spawn);
void crypto_drop_spawn(struct crypto_spawn *spawn)
{
- if (!spawn->alg)
- return;
-
down_write(&crypto_alg_sem);
- list_del(&spawn->list);
+ if (spawn->alg)
+ list_del(&spawn->list);
up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);
--
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] crypto: api - Check spawn->alg under lock in crypto_drop_spawn
2019-12-06 5:55 [PATCH] crypto: api - Check spawn->alg under lock in crypto_drop_spawn Herbert Xu
@ 2019-12-11 3:36 ` Eric Biggers
2019-12-11 8:27 ` Herbert Xu
0 siblings, 1 reply; 3+ messages in thread
From: Eric Biggers @ 2019-12-11 3:36 UTC (permalink / raw)
To: Herbert Xu; +Cc: Linux Crypto Mailing List
On Fri, Dec 06, 2019 at 01:55:17PM +0800, Herbert Xu wrote:
> We need to check whether spawn->alg is NULL under lock as otherwise
> the algorithm could be removed from under us after we have checked
> it and found it to be non-NULL. This could cause us to remove the
> spawn from a non-existent list.
>
> Fixes: 6bfd48096ff8 ("[CRYPTO] api: Added spawns")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
>
> diff --git a/crypto/algapi.c b/crypto/algapi.c
> index 783006f4d339..6869feb31c99 100644
> --- a/crypto/algapi.c
> +++ b/crypto/algapi.c
> @@ -668,11 +668,9 @@ EXPORT_SYMBOL_GPL(crypto_grab_spawn);
>
> void crypto_drop_spawn(struct crypto_spawn *spawn)
> {
> - if (!spawn->alg)
> - return;
> -
> down_write(&crypto_alg_sem);
> - list_del(&spawn->list);
> + if (spawn->alg)
> + list_del(&spawn->list);
> up_write(&crypto_alg_sem);
> }
> EXPORT_SYMBOL_GPL(crypto_drop_spawn);
Seems the Fixes tag is wrong. It should be:
Fixes: 7ede5a5ba55a ("crypto: api - Fix crypto_drop_spawn crash on blank spawns")
- Eric
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-12-11 8:28 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-12-06 5:55 [PATCH] crypto: api - Check spawn->alg under lock in crypto_drop_spawn Herbert Xu
2019-12-11 3:36 ` Eric Biggers
2019-12-11 8:27 ` Herbert Xu
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