path: root/crypto
diff options
authorEric Biggers <ebiggers@google.com>2017-11-05 18:30:46 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2017-11-10 19:20:17 +0800
commitccd9888f14a8019c0bbdeeae758aba1f58693712 (patch)
tree2e955d96c62a527a2ef03a70c261c52b9bac3f50 /crypto
parent199512b1234f09e44d592153ec82b44212b2f0c4 (diff)
crypto: dh - Don't permit 'key' or 'g' size longer than 'p'
The "qat-dh" DH implementation assumes that 'key' and 'g' can be copied into a buffer with size 'p_size'. However it was never checked that that was actually the case, which most likely allowed users to cause a buffer underflow via KEYCTL_DH_COMPUTE. Fix this by updating crypto_dh_decode_key() to verify this precondition for all DH implementations. Fixes: c9839143ebbf ("crypto: qat - Add DH support") Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
1 files changed, 8 insertions, 0 deletions
diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
index 788a9e572918..24fdb2ecaa85 100644
--- a/crypto/dh_helper.c
+++ b/crypto/dh_helper.c
@@ -83,6 +83,14 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
if (secret.len != crypto_dh_key_len(params))
return -EINVAL;
+ /*
+ * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since
+ * some drivers assume otherwise.
+ */
+ if (params->key_size > params->p_size ||
+ params->g_size > params->p_size)
+ return -EINVAL;
/* Don't allocate memory. Set pointers to data within
* the given buffer