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Subject: Re: [PATCH v7 6/8] certs: add wrapper function to check blacklisted
 binary hash
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Nayna Jain <nayna@linux.ibm.com>, linuxppc-dev@ozlabs.org,
        linux-efi@vger.kernel.org, linux-integrity@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Jeremy Kerr <jk@ozlabs.org>,
        Matthew Garret <matthew.garret@nebula.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Claudio Carvalho <cclaudio@linux.ibm.com>,
        George Wilson <gcwilson@linux.ibm.com>,
        Elaine Palmer <erpalmer@us.ibm.com>,
        Eric Ricther <erichte@linux.ibm.com>,
        "Oliver O'Halloran" <oohall@gmail.com>
Date:   Fri, 11 Oct 2019 09:18:17 -0400
In-Reply-To: <1570497267-13672-7-git-send-email-nayna@linux.ibm.com>
References: <1570497267-13672-1-git-send-email-nayna@linux.ibm.com>
         <1570497267-13672-7-git-send-email-nayna@linux.ibm.com>
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On Mon, 2019-10-07 at 21:14 -0400, Nayna Jain wrote:
> The existing is_hash_blacklisted() function returns -EKEYREJECTED
> error code for both the blacklisted keys and binaries.
> 
> This patch adds a wrapper function is_binary_blacklisted() to check
> against binary hashes and returns -EPERM.    
> 
> Signed-off-by: Nayna Jain <nayna@linux.ibm.com>

This patch description describes what you're doing, not the
motivation.

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

> ---
>  certs/blacklist.c             | 9 +++++++++
>  include/keys/system_keyring.h | 6 ++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/certs/blacklist.c b/certs/blacklist.c
> index ec00bf337eb6..6514f9ebc943 100644
> --- a/certs/blacklist.c
> +++ b/certs/blacklist.c
> @@ -135,6 +135,15 @@ int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
>  }
>  EXPORT_SYMBOL_GPL(is_hash_blacklisted);
>  
> +int is_binary_blacklisted(const u8 *hash, size_t hash_len)
> +{
> +	if (is_hash_blacklisted(hash, hash_len, "bin") == -EKEYREJECTED)
> +		return -EPERM;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(is_binary_blacklisted);
> +
>  /*
>   * Initialise the blacklist
>   */
> diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
> index c1a96fdf598b..fb8b07daa9d1 100644
> --- a/include/keys/system_keyring.h
> +++ b/include/keys/system_keyring.h
> @@ -35,12 +35,18 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
>  extern int mark_hash_blacklisted(const char *hash);
>  extern int is_hash_blacklisted(const u8 *hash, size_t hash_len,
>  			       const char *type);
> +extern int is_binary_blacklisted(const u8 *hash, size_t hash_len);
>  #else
>  static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len,
>  				      const char *type)
>  {
>  	return 0;
>  }
> +
> +static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len)
> +{
> +	return 0;
> +}
>  #endif
>  
>  #ifdef CONFIG_IMA_BLACKLIST_KEYRING