[PATCH v12 22/25] Audit: Include object data for all security modules
Stephen Smalley
sds at tycho.nsa.gov
Wed Dec 18 18:02:35 UTC 2019
On 12/16/19 5:36 PM, Casey Schaufler wrote:
> When there is more than one context displaying security
> module extend what goes into the audit record by supplimenting
> the "obj=" with an "obj_<lsm>=" for each such security
> module.
>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Disclaimer: requires ack by audit maintainers. For me,
Acked-by: Stephen Smalley <sds at tycho.nsa.gov>
> ---
> kernel/audit.h | 4 +-
> kernel/auditsc.c | 110 ++++++++++++++++++++++++-----------------------
> 2 files changed, 58 insertions(+), 56 deletions(-)
>
> diff --git a/kernel/audit.h b/kernel/audit.h
> index af9bc09e656c..c9f1e1641542 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -78,7 +78,7 @@ struct audit_names {
> kuid_t uid;
> kgid_t gid;
> dev_t rdev;
> - u32 osid;
> + struct lsmblob oblob;
> struct audit_cap_data fcap;
> unsigned int fcap_ver;
> unsigned char type; /* record type */
> @@ -152,7 +152,7 @@ struct audit_context {
> kuid_t uid;
> kgid_t gid;
> umode_t mode;
> - u32 osid;
> + struct lsmblob oblob;
> int has_perm;
> uid_t perm_uid;
> gid_t perm_gid;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index e0dd643e9b13..0c071947c2b3 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -659,17 +659,15 @@ static int audit_filter_rules(struct task_struct *tsk,
> if (f->lsm_rule) {
> /* Find files that match */
> if (name) {
> - lsmblob_init(&blob, name->osid);
> result = security_audit_rule_match(
> - &blob,
> + &name->oblob,
> f->type,
> f->op,
> f->lsm_rule);
> } else if (ctx) {
> list_for_each_entry(n, &ctx->names_list, list) {
> - lsmblob_init(&blob, n->osid);
> if (security_audit_rule_match(
> - &blob,
> + &n->oblob,
> f->type,
> f->op,
> f->lsm_rule)) {
> @@ -681,8 +679,7 @@ static int audit_filter_rules(struct task_struct *tsk,
> /* Find ipc objects that match */
> if (!ctx || ctx->type != AUDIT_IPC)
> break;
> - lsmblob_init(&blob, ctx->ipc.osid);
> - if (security_audit_rule_match(&blob,
> + if (security_audit_rule_match(&ctx->ipc.oblob,
> f->type, f->op,
> f->lsm_rule))
> ++result;
> @@ -956,13 +953,57 @@ static inline void audit_free_context(struct audit_context *context)
> kfree(context);
> }
>
> +static int audit_log_object_context(struct audit_buffer *ab,
> + struct lsmblob *blob)
> +{
> + struct lsmcontext context;
> + const char *lsm;
> + int i;
> +
> + /*
> + * None of the installed modules have object labels.
> + */
> + if (security_lsm_slot_name(0) == NULL)
> + return 0;
> +
> + if (blob->secid[0] != 0) {
> + if (security_secid_to_secctx(blob, &context, 0)) {
> + audit_log_format(ab, " obj=?");
> + return 1;
> + }
> + audit_log_format(ab, " obj=%s", context.context);
> + security_release_secctx(&context);
> + }
> +
> + /*
> + * Don't do anything more unless there is more than one LSM
> + * with a security context to report.
> + */
> + if (security_lsm_slot_name(1) == NULL)
> + return 0;
> +
> + for (i = 0; i < LSMBLOB_ENTRIES; i++) {
> + lsm = security_lsm_slot_name(i);
> + if (lsm == NULL)
> + break;
> + if (blob->secid[i] == 0)
> + continue;
> + if (security_secid_to_secctx(blob, &context, i)) {
> + audit_log_format(ab, " obj_%s=?", lsm);
> + continue;
> + }
> + audit_log_format(ab, " obj_%s=%s", lsm, context.context);
> + security_release_secctx(&context);
> + }
> + return 0;
> +}
> +
> static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> kuid_t auid, kuid_t uid,
> unsigned int sessionid,
> struct lsmblob *blob, char *comm)
> {
> struct audit_buffer *ab;
> - struct lsmcontext lsmctx;
> int rc = 0;
>
> ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> @@ -972,15 +1013,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
> from_kuid(&init_user_ns, auid),
> from_kuid(&init_user_ns, uid), sessionid);
> - if (lsmblob_is_set(blob)) {
> - if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) {
> - audit_log_format(ab, " obj=(none)");
> - rc = 1;
> - } else {
> - audit_log_format(ab, " obj=%s", lsmctx.context);
> - security_release_secctx(&lsmctx);
> - }
> - }
> + rc = audit_log_object_context(ab, blob);
> audit_log_format(ab, " ocomm=");
> audit_log_untrustedstring(ab, comm);
> audit_log_end(ab);
> @@ -1207,26 +1240,14 @@ static void show_special(struct audit_context *context, int *call_panic)
> context->socketcall.args[i]);
> break; }
> case AUDIT_IPC: {
> - u32 osid = context->ipc.osid;
> + struct lsmblob *oblob = & context->ipc.oblob;
>
> audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
> from_kuid(&init_user_ns, context->ipc.uid),
> from_kgid(&init_user_ns, context->ipc.gid),
> context->ipc.mode);
> - if (osid) {
> - struct lsmcontext lsmcxt;
> - struct lsmblob blob;
> -
> - lsmblob_init(&blob, osid);
> - if (security_secid_to_secctx(&blob, &lsmcxt,
> - LSMBLOB_FIRST)) {
> - audit_log_format(ab, " osid=%u", osid);
> - *call_panic = 1;
> - } else {
> - audit_log_format(ab, " obj=%s", lsmcxt.context);
> - security_release_secctx(&lsmcxt);
> - }
> - }
> + if (audit_log_object_context(ab, oblob))
> + *call_panic = 1;
> if (context->ipc.has_perm) {
> audit_log_end(ab);
> ab = audit_log_start(context, GFP_KERNEL,
> @@ -1366,20 +1387,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
> from_kgid(&init_user_ns, n->gid),
> MAJOR(n->rdev),
> MINOR(n->rdev));
> - if (n->osid != 0) {
> - struct lsmblob blob;
> - struct lsmcontext lsmctx;
> -
> - lsmblob_init(&blob, n->osid);
> - if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) {
> - audit_log_format(ab, " osid=%u", n->osid);
> - if (call_panic)
> - *call_panic = 2;
> - } else {
> - audit_log_format(ab, " obj=%s", lsmctx.context);
> - security_release_secctx(&lsmctx);
> - }
> - }
> + if (audit_log_object_context(ab, &n->oblob) && call_panic)
> + *call_panic = 2;
>
> /* log the audit_names record type */
> switch (n->type) {
> @@ -1929,17 +1938,13 @@ static void audit_copy_inode(struct audit_names *name,
> const struct dentry *dentry,
> struct inode *inode, unsigned int flags)
> {
> - struct lsmblob blob;
> -
> name->ino = inode->i_ino;
> name->dev = inode->i_sb->s_dev;
> name->mode = inode->i_mode;
> name->uid = inode->i_uid;
> name->gid = inode->i_gid;
> name->rdev = inode->i_rdev;
> - security_inode_getsecid(inode, &blob);
> - /* scaffolding until osid is updated */
> - name->osid = blob.secid[0];
> + security_inode_getsecid(inode, &name->oblob);
> if (flags & AUDIT_INODE_NOEVAL) {
> name->fcap_ver = -1;
> return;
> @@ -2285,14 +2290,11 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
> void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
> {
> struct audit_context *context = audit_context();
> - struct lsmblob blob;
> context->ipc.uid = ipcp->uid;
> context->ipc.gid = ipcp->gid;
> context->ipc.mode = ipcp->mode;
> context->ipc.has_perm = 0;
> - security_ipc_getsecid(ipcp, &blob);
> - /* scaffolding on the [0] - change "osid" to a lsmblob */
> - context->ipc.osid = blob.secid[0];
> + security_ipc_getsecid(ipcp, &context->ipc.oblob);
> context->type = AUDIT_IPC;
> }
>
>
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