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authorEric Biggers <ebiggers@google.com>2018-02-22 14:38:33 +0000
committerDavid Howells <dhowells@redhat.com>2018-02-22 14:38:33 +0000
commit437499eea4291ae9621e8763a41df027c110a1ef (patch)
tree93da0e30e6a005bd7dedd19b998ea1d81311dcb1
parent6459ae386699a5fe0dc52cf30255f75274fa43a4 (diff)
X.509: fix BUG_ON() when hash algorithm is unsupported
The X.509 parser mishandles the case where the certificate's signature's hash algorithm is not available in the crypto API. In this case, x509_get_sig_params() doesn't allocate the cert->sig->digest buffer; this part seems to be intentional. However, public_key_verify_signature() is still called via x509_check_for_self_signed(), which triggers the 'BUG_ON(!sig->digest)'. Fix this by making public_key_verify_signature() return -ENOPKG if the hash buffer has not been allocated. Reproducer when all the CONFIG_CRYPTO_SHA512* options are disabled: openssl req -new -sha512 -x509 -batch -nodes -outform der \ | keyctl padd asymmetric desc @s Fixes: 6c2dc5ae4ab7 ("X.509: Extract signature digest and make self-signed cert checks earlier") Reported-by: Paolo Valente <paolo.valente@linaro.org> Cc: Paolo Valente <paolo.valente@linaro.org> Cc: <stable@vger.kernel.org> # v4.7+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
-rw-r--r--crypto/asymmetric_keys/public_key.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index de996586762a..e929fe1e4106 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -79,9 +79,11 @@ int public_key_verify_signature(const struct public_key *pkey,
BUG_ON(!pkey);
BUG_ON(!sig);
- BUG_ON(!sig->digest);
BUG_ON(!sig->s);
+ if (!sig->digest)
+ return -ENOPKG;
+
alg_name = sig->pkey_algo;
if (strcmp(sig->pkey_algo, "rsa") == 0) {
/* The data wangled by the RSA algorithm is typically padded