Re: [RFC PATCH v1 1/7] lsm: Add audit_log_lsm_data() helper

[Paul Moore]

On Thu, Sep 21, 2023 at 2:16 AM Mickaël Salaün <mic@xxxxxxxxxxx> wrote:
>
> Extract code from common_dump_audit_data() into the audit_log_lsm_data()

Did you mean dump_common_audit_data()?  Assuming you correct the
function name above this looks fine to me.

Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx>

> helper. This helps reuse common LSM audit data while not abusing
> AUDIT_AVC records because of the common_lsm_audit() helper.
>
> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
> ---
>  include/linux/lsm_audit.h |  2 ++
>  security/lsm_audit.c      | 26 +++++++++++++++++---------
>  2 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
> index 97a8b21eb033..5f9a7ed0e7a5 100644
> --- a/include/linux/lsm_audit.h
> +++ b/include/linux/lsm_audit.h
> @@ -122,6 +122,8 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
>  int ipv6_skb_to_auditdata(struct sk_buff *skb,
>                 struct common_audit_data *ad, u8 *proto);
>
> +void audit_log_lsm_data(struct audit_buffer *ab, struct common_audit_data *a);
> +
>  void common_lsm_audit(struct common_audit_data *a,
>         void (*pre_audit)(struct audit_buffer *, void *),
>         void (*post_audit)(struct audit_buffer *, void *));
> diff --git a/security/lsm_audit.c b/security/lsm_audit.c
> index 849e832719e2..58f9b8bde22a 100644
> --- a/security/lsm_audit.c
> +++ b/security/lsm_audit.c
> @@ -189,16 +189,12 @@ static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
>  }
>
>  /**
> - * dump_common_audit_data - helper to dump common audit data
> + * audit_log_lsm_data - helper to log common LSM audit data
>   * @ab : the audit buffer
>   * @a : common audit data
> - *
>   */
> -static void dump_common_audit_data(struct audit_buffer *ab,
> -                                  struct common_audit_data *a)
> +void audit_log_lsm_data(struct audit_buffer *ab, struct common_audit_data *a)
>  {
> -       char comm[sizeof(current->comm)];
> -
>         /*
>          * To keep stack sizes in check force programmers to notice if they
>          * start making this union too large!  See struct lsm_network_audit
> @@ -206,9 +202,6 @@ static void dump_common_audit_data(struct audit_buffer *ab,
>          */
>         BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
>
> -       audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
> -       audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
> -
>         switch (a->type) {
>         case LSM_AUDIT_DATA_NONE:
>                 return;
> @@ -428,6 +421,21 @@ static void dump_common_audit_data(struct audit_buffer *ab,
>         } /* switch (a->type) */
>  }
>
> +/**
> + * dump_common_audit_data - helper to dump common audit data
> + * @ab : the audit buffer
> + * @a : common audit data
> + */
> +static void dump_common_audit_data(struct audit_buffer *ab,
> +                                  struct common_audit_data *a)
> +{
> +       char comm[sizeof(current->comm)];
> +
> +       audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
> +       audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
> +       audit_log_lsm_data(ab, a);
> +}
> +
>  /**
>   * common_lsm_audit - generic LSM auditing function
>   * @a:  auxiliary audit data
> --
> 2.42.0

--
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