2017-11-24 08:22:07

by Corentin LABBE

Subject: [PATCH v2] ARM64: crypto: do not call crypto_unregister_skcipher twice on error

When a cipher fails to register in aes_init(), the error path goes thought
aes_exit() then crypto_unregister_skciphers().
Since aes_exit calls also crypto_unregister_skcipher, this triggers a
refcount_t: underflow; use-after-free.

Signed-off-by: Corentin Labbe <[email protected]>
---
Changes since v1:
- Instead of duplicate code from aes_exit() minus crypto_unregister_skciphers, simply use it and return after
as suggested by Ard Biesheuvel
arch/arm64/crypto/aes-glue.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index 998ba519a026..2fa850e86aa8 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -665,6 +665,7 @@ static int __init aes_init(void)

unregister_simds:
aes_exit();
+ return err;
unregister_ciphers:
crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
return err;
--
2.13.6

2017-11-29 06:40:09

by Herbert Xu

Subject: Re: [PATCH v2] ARM64: crypto: do not call crypto_unregister_skcipher twice on error

On Fri, Nov 24, 2017 at 08:22:07AM +0000, Corentin Labbe wrote:
> When a cipher fails to register in aes_init(), the error path goes thought
> aes_exit() then crypto_unregister_skciphers().
> Since aes_exit calls also crypto_unregister_skcipher, this triggers a
> refcount_t: underflow; use-after-free.
>
> Signed-off-by: Corentin Labbe <[email protected]>

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt