diff options
| author | Eric Biggers <ebiggers@google.com> | 2017-04-19 22:46:29 -0700 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2017-05-03 18:00:40 +0100 |
| commit | 4172edde149a4580fb59eb25c41d459e9a193633 (patch) | |
| tree | 3d2436886a43062097be2cfc17f825b379314853 /security | |
| parent | b5895237b035cab448a0b727f54bdae8d234b180 (diff) | |
KEYS: DH: forbid using digest_null as the KDF hash
Requesting "digest_null" in the keyctl_kdf_params caused an infinite
loop in kdf_ctr() because the "null" hash has a digest size of 0. Fix
it by rejecting hash algorithms with a digest size of 0.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Diffstat (limited to 'security')
| -rw-r--r-- | security/keys/dh.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/security/keys/dh.c b/security/keys/dh.c index e603bd912e4c..8abc70ebe22d 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -89,6 +89,7 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname) struct crypto_shash *tfm; struct kdf_sdesc *sdesc; int size; + int err; /* allocate synchronous hash */ tfm = crypto_alloc_shash(hashname, 0, 0); @@ -97,16 +98,25 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname) return PTR_ERR(tfm); } + err = -EINVAL; + if (crypto_shash_digestsize(tfm) == 0) + goto out_free_tfm; + + err = -ENOMEM; size = sizeof(struct shash_desc) + crypto_shash_descsize(tfm); sdesc = kmalloc(size, GFP_KERNEL); if (!sdesc) - return -ENOMEM; + goto out_free_tfm; sdesc->shash.tfm = tfm; sdesc->shash.flags = 0x0; *sdesc_ret = sdesc; return 0; + +out_free_tfm: + crypto_free_shash(tfm); + return err; } static void kdf_dealloc(struct kdf_sdesc *sdesc) |