Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 06/28] crypto: dh - Dont permit key or g size longer than p | Date | Sun, 19 Nov 2017 15:43:53 +0100 |
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4.13-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 */
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