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authorHerbert Xu <herbert@gondor.apana.org.au>2013-09-08 14:33:50 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2013-09-08 14:33:50 +1000
commit77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa (patch)
tree04a1f5c8dbe70783c35d1b378fcb73e8ddf609ea /crypto
parent6be48f2940af9ea8d93c23a0dd8e322672c92efd (diff)
downloadlinux-linaro-stable-77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa.tar.gz
crypto: api - Fix race condition in larval lookup
crypto_larval_lookup should only return a larval if it created one. Any larval created by another entity must be processed through crypto_larval_wait before being returned. Otherwise this will lead to a larval being killed twice, which will most likely lead to a crash. Cc: stable@vger.kernel.org Reported-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/api.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/crypto/api.c b/crypto/api.c
index 320ea4d8a0f5..a2b39c5f3649 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -34,6 +34,8 @@ EXPORT_SYMBOL_GPL(crypto_alg_sem);
BLOCKING_NOTIFIER_HEAD(crypto_chain);
EXPORT_SYMBOL_GPL(crypto_chain);
+static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
+
struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
{
return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
@@ -144,8 +146,11 @@ static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
}
up_write(&crypto_alg_sem);
- if (alg != &larval->alg)
+ if (alg != &larval->alg) {
kfree(larval);
+ if (crypto_is_larval(alg))
+ alg = crypto_larval_wait(alg);
+ }
return alg;
}