| Message ID | 20171106023048.8067-4-ebiggers3@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
On 11/06/2017 04:30 AM, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > 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+ Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com> > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > crypto/dh_helper.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c > index 708ae20d2d3c..7f00c771fe8d 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 > */ >
diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c index 708ae20d2d3c..7f00c771fe8d 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 */