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| author | Eric Biggers <ebiggers@google.com> | 2017-06-08 14:49:34 +0100 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2017-06-09 13:29:49 +1000 |
| commit | bbe240454d86be95151e0ecfd6ac55fe5ef5a6f5 (patch) | |
| tree | 662839ffc98b691fe598cef81a1bab0c2b123ccd /security/keys | |
| parent | 0620fddb56dfaf0e1034eeb69d79c73b361debbf (diff) | |
| download | linux-bbe240454d86be95151e0ecfd6ac55fe5ef5a6f5.tar.gz | |
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> Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'security/keys')
| -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) |