4.9-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
commit ccd9888f14a8019c0bbdeeae758aba1f58693712 upstream.
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") 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/dh_helper.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/crypto/dh_helper.c +++ b/crypto/dh_helper.c @@ -83,6 +83,14 @@ int crypto_dh_decode_key(const char *buf 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 */