diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2013-09-08 08:33:50 +0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-10-27 00:06:03 +0400 |
| commit | 4741b69849e0b01077becf6d2cb902dca9984d01 (patch) | |
| tree | 105ad82f742444c8e054a8271561d93b7e70b147 /crypto/api.c | |
| parent | fbeecda256bab53034d5a7f0c79c2f99219ce7c3 (diff) | |
| download | linux-4741b69849e0b01077becf6d2cb902dca9984d01.tar.xz | |
crypto: api - Fix race condition in larval lookup
commit 77dbd7a95e4a4f15264c333a9e9ab97ee27dc2aa upstream.
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.
Reported-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'crypto/api.c')
| -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 033a7147e5eb..cea3cf6c9897 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); + static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) { atomic_inc(&alg->cra_refcnt); @@ -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; } |