45 lines
1.4 KiB
Diff
45 lines
1.4 KiB
Diff
commit 77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa
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Author: Herbert Xu <herbert@gondor.apana.org.au>
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Date: Sun Sep 8 14:33:50 2013 +1000
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crypto: api - Fix race condition in larval lookup
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crypto_larval_lookup should only return a larval if it created one.
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Any larval created by another entity must be processed through
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crypto_larval_wait before being returned.
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Otherwise this will lead to a larval being killed twice, which
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will most likely lead to a crash.
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Cc: stable@vger.kernel.org
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Reported-by: Kees Cook <keescook@chromium.org>
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Tested-by: Kees Cook <keescook@chromium.org>
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Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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diff --git a/crypto/api.c b/crypto/api.c
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index 320ea4d..a2b39c5 100644
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--- a/crypto/api.c
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+++ b/crypto/api.c
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@@ -34,6 +34,8 @@ EXPORT_SYMBOL_GPL(crypto_alg_sem);
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BLOCKING_NOTIFIER_HEAD(crypto_chain);
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EXPORT_SYMBOL_GPL(crypto_chain);
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+static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
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+
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struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
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{
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return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
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@@ -144,8 +146,11 @@ static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
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}
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up_write(&crypto_alg_sem);
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- if (alg != &larval->alg)
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+ if (alg != &larval->alg) {
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kfree(larval);
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+ if (crypto_is_larval(alg))
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+ alg = crypto_larval_wait(alg);
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+ }
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return alg;
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}
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