Re: [PATCH 1/2] auvirt: Improve matching of AVC records generated by SELinux

[Steve Grubb <sgrubb@redhat.com>]

On Monday, February 20, 2012 01:15:46 PM Marcelo Cerri wrote:
> With this patch, auvirt also matches AVC denials performed by the guest and
> generated by SELinux.

Applied.

-Steve


>  tools/auvirt/auvirt.c |   52
> ++++++++++++++++++++++++++++++------------------ 1 files changed, 32
> insertions(+), 20 deletions(-)
> 
> diff --git a/tools/auvirt/auvirt.c b/tools/auvirt/auvirt.c
> index 9b71a3c..a49a8b8 100644
> --- a/tools/auvirt/auvirt.c
> +++ b/tools/auvirt/auvirt.c
> @@ -87,10 +87,10 @@ struct event {
>  	/* Fields specific for machine id events: */
>  	char *seclevel;
>  	/* Fields specific for avc events: */
> +	char *avc_result;
> +	char *avc_operation;
>  	char *target;
>  	char *comm;
> -	char *seresult;
> -	char *seperms;
>  	char *context;
>  	/* Fields to print proof information: */
>  	struct record_id proof[4];
> @@ -123,11 +123,11 @@ void event_free(struct event *event)
>  		free(event->reason);
>  		free(event->res_type);
>  		free(event->res);
> +		free(event->avc_result);
> +		free(event->avc_operation);
>  		free(event->seclevel);
>  		free(event->target);
>  		free(event->comm);
> -		free(event->seresult);
> -		free(event->seperms);
>  		free(event->cgroup_class);
>  		free(event->cgroup_detail);
>  		free(event->cgroup_acl);
> @@ -468,7 +468,7 @@ int process_machine_id_event(auparse_state_t *au)
>  	seclevel = get_seclevel(auparse_find_field(au, "vm-ctx"));
>  	if (seclevel == NULL) {
>  		if (debug)
> -			fprintf(stderr, "security context not found for "
> +			fprintf(stderr, "Security context not found for "
>  					"MACHINE_ID event.\n");
>  	}
> 
> @@ -592,7 +592,7 @@ int add_stop_guest_event(auparse_state_t *au)
>  	}
>  	if (start == NULL) {
>  		if (debug) {
> -			fprintf(stderr, "Couldn't find the correlated start i"
> +			fprintf(stderr, "Couldn't find the correlated start "
>  					"record to the stop event.\n");
>  		}
>  		return 0;
> @@ -824,19 +824,18 @@ struct event *get_machine_id_by_seclevel(const char
> *seclevel) return machine_id;
>  }
> 
> -/* AVC records are correlated to guest through the selinux context. */
> -int process_avc(auparse_state_t *au)
> +int process_avc_selinux_context(auparse_state_t *au, const char *context)
>  {
>  	const char *target, *seclevel;
>  	struct event *machine_id, *avc;
>  	uid_t uid;
>  	time_t time;
> 
> -	seclevel = get_seclevel(auparse_find_field(au, "tcontext"));
> +	seclevel = get_seclevel(auparse_find_field(au, context));
>  	if (seclevel == NULL) {
>  		if (debug) {
> -			fprintf(stderr, "Security context not found for "
> -					"AVC event.\n");
> +			fprintf(stderr, "Security context not found "
> +					"for AVC event.\n");
>  		}
>  		return 0;
>  	}
> @@ -847,8 +846,8 @@ int process_avc(auparse_state_t *au)
>  	machine_id = get_machine_id_by_seclevel(seclevel);
>  	if (machine_id == NULL) {
>  		if (debug) {
> -			fprintf(stderr, "Couldn't get the security level from "
> -					"the AVC event.\n");
> +			fprintf(stderr, "Couldn't get the security "
> +					"level from the AVC event.\n");
>  		}
>  		return 0;
>  	}
> @@ -868,19 +867,19 @@ int process_avc(auparse_state_t *au)
>  	avc->uid = uid;
>  	avc->seclevel = copy_str(seclevel);
>  	auparse_first_record(au);
> -	avc->seresult = copy_str(auparse_find_field(au, "seresult"));
> -	avc->seperms = copy_str(auparse_find_field(au, "seperms"));
> +	avc->avc_result = copy_str(auparse_find_field(au, "seresult"));
> +	avc->avc_operation = copy_str(auparse_find_field(au, "seperms"));
>  	if (auparse_find_field(au, "comm"))
>  		avc->comm = copy_str(auparse_interpret_field(au));
>  	if (auparse_find_field(au, "name"))
>  		avc->target = copy_str(auparse_interpret_field(au));
> 
>  	/* get the context related to the permission that was denied. */
> -	if (avc->seperms) {
> +	if (avc->avc_operation) {
>  		const char *ctx = NULL;
> -		if (strcmp("relabelfrom", avc->seperms) == 0) {
> +		if (strcmp("relabelfrom", avc->avc_operation) == 0) {
>  			ctx = auparse_find_field(au, "scontext");
> -		} else if (strcmp("relabelto", avc->seperms) == 0) {
> +		} else if (strcmp("relabelto", avc->avc_operation) == 0) {
>  			ctx = auparse_find_field(au, "tcontext");
>  		}
>  		avc->context = copy_str(ctx);
> @@ -894,6 +893,19 @@ int process_avc(auparse_state_t *au)
>  	return 0;
>  }
> 
> +/* AVC records are correlated to guest through the selinux context. */
> +int process_avc(auparse_state_t *au)
> +{
> +	const char **context;
> +	const char *contexts[] = { "tcontext", "scontext", NULL };
> +
> +	for (context = contexts; context && *context; context++) {
> +		if (process_avc_selinux_context(au, *context))
> +			return 1;
> +	}
> +	return 0;
> +}
> +
>  /* This function tries to correlate an anomaly record to a guest using the
> qemu * pid or the selinux context. */
>  int process_anom(auparse_state_t *au)
> @@ -1152,8 +1164,8 @@ void print_event(struct event *event)
>  	} else if (event->type == ET_MACHINE_ID) {
>  		printf("\t%s", N(event->seclevel));
>  	} else if (event->type == ET_AVC) {
> -		printf("\t%-12.12s", N(event->seperms));
> -		printf("\t%-10.10s", N(event->seresult));
> +		printf("\t%-12.12s", N(event->avc_operation));
> +		printf("\t%-10.10s", N(event->avc_result));
>  		printf("\t%s\t%s\t%s", N(event->comm), N(event->target),
>  				N(event->context));
>  	}