6.15-stable review patch. If anyone has any objections, please let me know.
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From: Herbert Xu herbert@gondor.apana.org.au
[ Upstream commit 0a3cf32da469ff1df6e016f5f82b439a63d14461 ]
When two crypto algorithm lookups occur at the same time with different names for the same algorithm, e.g., ctr(aes-generic) and ctr(aes), they will both be instantiated. However, only one of them can be registered. The second instantiation will fail with EEXIST.
Avoid failing the second lookup by making it retry, but only once because there are tricky names such as gcm_base(ctr(aes),ghash) that will always fail, despite triggering instantiation and EEXIST.
Reported-by: Ingo Franzki ifranzki@linux.ibm.com Fixes: 2825982d9d66 ("[CRYPTO] api: Added event notification") Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/api.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/crypto/api.c b/crypto/api.c index 3416e98128a05..8592d3dccc64e 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -220,10 +220,19 @@ static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg, if (crypto_is_test_larval(larval)) crypto_larval_kill(larval); alg = ERR_PTR(-ETIMEDOUT); - } else if (!alg) { + } else if (!alg || PTR_ERR(alg) == -EEXIST) { + int err = alg ? -EEXIST : -EAGAIN; + + /* + * EEXIST is expected because two probes can be scheduled + * at the same time with one using alg_name and the other + * using driver_name. Do a re-lookup but do not retry in + * case we hit a quirk like gcm_base(ctr(aes),...) which + * will never match. + */ alg = &larval->alg; alg = crypto_alg_lookup(alg->cra_name, type, mask) ?: - ERR_PTR(-EAGAIN); + ERR_PTR(err); } else if (IS_ERR(alg)) ; else if (crypto_is_test_larval(larval) &&