Re: [ima-evm-utils PATCH 02/12] Free public keys list

From: Stefan Berger <stefanb@linux.ibm.com>
To: Mimi Zohar <zohar@linux.ibm.com>, linux-integrity@vger.kernel.org
Subject: Re: [ima-evm-utils PATCH 02/12] Free public keys list
Date: Wed, 22 Nov 2023 07:52:37 -0500	[thread overview]
Message-ID: <5bd2569f-9aa6-4938-88f1-513451427e81@linux.ibm.com> (raw)
In-Reply-To: <20231119165043.46960-3-zohar@linux.ibm.com>

On 11/19/23 11:50, Mimi Zohar wrote:
> On failure to allocate memory, free the public keys list.
> 
> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> ---
>   src/imaevm.h    |  1 +
>   src/libimaevm.c | 17 +++++++++++++++++
>   2 files changed, 18 insertions(+)
> 
> diff --git a/src/imaevm.h b/src/imaevm.h
> index 18d7b0e447e1..828976e52881 100644
> --- a/src/imaevm.h
> +++ b/src/imaevm.h
> @@ -249,6 +249,7 @@ uint32_t imaevm_read_keyid(const char *certfile);
>   int sign_hash(const char *algo, const unsigned char *hash, int size, const char *keyfile, const char *keypass, unsigned char *sig);
>   int verify_hash(const char *file, const unsigned char *hash, int size, unsigned char *sig, int siglen);
>   int ima_verify_signature(const char *file, unsigned char *sig, int siglen, unsigned char *digest, int digestlen);
> +void free_public_keys(void *public_keys);
>   void init_public_keys(const char *keyfiles);
>   int imaevm_hash_algo_from_sig(unsigned char *sig);
>   const char *imaevm_hash_algo_by_id(int algo);
> diff --git a/src/libimaevm.c b/src/libimaevm.c
> index 117a1a72b60c..74e9d09b1f05 100644
> --- a/src/libimaevm.c
> +++ b/src/libimaevm.c
> @@ -399,11 +399,25 @@ static EVP_PKEY *find_keyid(uint32_t keyid)
>   	return 0;
>   }
>   
> +void free_public_keys(void *public_keys)
> +{
> +	struct public_key_entry *entry = public_keys, *next;
> +
> +	while (entry != NULL) {
> +		next = entry->next;
> +		if (entry->key)
> +			free(entry->key);
> +		free(entry);
> +		entry = next;
> +	}
> +}
> +
>   void init_public_keys(const char *keyfiles)
>   {
>   	struct public_key_entry *entry;
>   	char *tmp_keyfiles, *keyfiles_free;
>   	char *keyfile;
> +	int err = 0;
>   	int i = 1;
>   
>   	tmp_keyfiles = strdup(keyfiles);
> @@ -417,6 +431,7 @@ void init_public_keys(const char *keyfiles)
>   		entry = malloc(sizeof(struct public_key_entry));
>   		if (!entry) {
>   			perror("malloc");
> +			err = -ENOMEM;
>   			break;
>   		}
>   
> @@ -433,6 +448,8 @@ void init_public_keys(const char *keyfiles)
>   		g_public_keys = entry;
>   	}
>   	free(keyfiles_free);
> +	if (err < 0)
> +		free_public_keys(g_public_keys);
>   }
>   
>   /*

Unfortunately you cannot return the err to callers...

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>