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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2019-12-06 13:55:17 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-11 04:35:22 -0800 |
| commit | ce832d16ce76b1aeb0e2fbe81aad330d2a9d1c44 (patch) | |
| tree | d9104b8b7996c704ca5081b5f070165220f8962d | |
| parent | 11528652a62a77fe4ba8361065114d9da1b71a29 (diff) | |
| download | linux-crypto-ce832d16ce76b1aeb0e2fbe81aad330d2a9d1c44.tar.gz linux-crypto-ce832d16ce76b1aeb0e2fbe81aad330d2a9d1c44.zip | |
crypto: api - Check spawn->alg under lock in crypto_drop_spawn
commit bc39d9486351deb0881a382c6c2d52b73467d304 upstream.
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: d0bb12bd1529 ("crypto: api - Fix crypto_drop_spawn crash...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | crypto/algapi.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/crypto/algapi.c b/crypto/algapi.c index de30ddc9..b860889e 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -669,11 +669,9 @@ 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); |