From a760a6656e6f00bb0144a42a048cf0266646e22c Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 26 Feb 2009 14:06:31 +0800 Subject: crypto: api - Fix module load deadlock with fallback algorithms With the mandatory algorithm testing at registration, we have now created a deadlock with algorithms requiring fallbacks. This can happen if the module containing the algorithm requiring fallback is loaded first, without the fallback module being loaded first. The system will then try to test the new algorithm, find that it needs to load a fallback, and then try to load that. As both algorithms share the same module alias, it can attempt to load the original algorithm again and block indefinitely. As algorithms requiring fallbacks are a special case, we can fix this by giving them a different module alias than the rest. Then it's just a matter of using the right aliases according to what algorithms we're trying to find. Signed-off-by: Herbert Xu --- crypto/api.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'crypto') diff --git a/crypto/api.c b/crypto/api.c index efe77df6863..38a2bc02a98 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -215,8 +215,19 @@ struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask) mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); type &= mask; - alg = try_then_request_module(crypto_alg_lookup(name, type, mask), - name); + alg = crypto_alg_lookup(name, type, mask); + if (!alg) { + char tmp[CRYPTO_MAX_ALG_NAME]; + + request_module(name); + + if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask) && + snprintf(tmp, sizeof(tmp), "%s-all", name) < sizeof(tmp)) + request_module(tmp); + + alg = crypto_alg_lookup(name, type, mask); + } + if (alg) return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg; -- cgit v1.2.3-70-g09d2