[PATCH 1/2] auvirt: Improve matching of AVC records generated by SELinux
Steve Grubb
sgrubb at redhat.com
Tue Feb 28 23:19:17 UTC 2012
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));
> }
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