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| author | Nikola Pajkovsky <npajkovs@redhat.com> | 2013-10-11 08:48:34 +0200 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2014-05-19 07:53:30 +0200 |
| commit | 8ec40cab58d3b334077ff0f7bbc0f667c43f1583 (patch) | |
| tree | 6a2a11986af24ee254fbc5a00d1186c8cdc5dc33 | |
| parent | 70630fa3b7148ee07828587fedbf0ad3f895c8e8 (diff) | |
| download | lwn-8ec40cab58d3b334077ff0f7bbc0f667c43f1583.tar.gz lwn-8ec40cab58d3b334077ff0f7bbc0f667c43f1583.zip | |
crypto: api - Fix race condition in larval lookup
https://bugzilla.redhat.com/1016108
64z is missing rhel6 commit 3af031a395c0 ("[crypto] algboss: Hold ref
count on larval") which is causing cosmetic fuzz, because crypto_alg_get
was move from crypto/api.c to crypto/internal.h.
From: Herbert Xu <herbert@gondor.apana.org.au>
[ upstream commit 77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa ]
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>
Signed-off-by: Nikola Pajkovsky <npajkovs@redhat.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | crypto/api.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/crypto/api.c b/crypto/api.c index 798526d90538..f4be65f9b6ae 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -40,6 +40,8 @@ static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) return alg; } +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; @@ -150,8 +152,11 @@ 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; } |