Messages in this thread | | | Subject | Re: [PATCH v2 1/3] evm: check hash algorithm passed to init_desc() | From | Mimi Zohar <> | Date | Thu, 30 May 2019 07:53:37 -0400 |
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On Wed, 2019-05-29 at 15:30 +0200, Roberto Sassu wrote: > This patch prevents memory access beyond the evm_tfm array by checking the > validity of the index (hash algorithm) passed to init_desc(). The hash > algorithm can be arbitrarily set if the security.ima xattr type is not > EVM_XATTR_HMAC. > > Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures") > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > Cc: stable@vger.kernel.org
Thanks, queued.
> --- > security/integrity/evm/evm_crypto.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c > index e11564eb645b..82a38e801ee4 100644 > --- a/security/integrity/evm/evm_crypto.c > +++ b/security/integrity/evm/evm_crypto.c > @@ -89,6 +89,9 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo) > tfm = &hmac_tfm; > algo = evm_hmac; > } else { > + if (hash_algo >= HASH_ALGO__LAST) > + return ERR_PTR(-EINVAL); > + > tfm = &evm_tfm[hash_algo]; > algo = hash_algo_name[hash_algo]; > }
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