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| author | Eric Biggers <ebiggers@google.com> | 2017-11-05 18:30:46 -0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-11-10 19:20:17 +0800 |
| commit | ccd9888f14a8019c0bbdeeae758aba1f58693712 (patch) | |
| tree | 2e955d96c62a527a2ef03a70c261c52b9bac3f50 | |
| parent | 199512b1234f09e44d592153ec82b44212b2f0c4 (diff) | |
| download | linux-ccd9888f14a8019c0bbdeeae758aba1f58693712.tar.bz2 | |
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>
| -rw-r--r-- | crypto/dh_helper.c | 8 |
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 */ |