Re: [PATCH v35 22/29] Audit: Keep multiple LSM data in audit_names

John Johansen
2022-04-25T23:32:16Z

On 4/18/22 07:59, Casey Schaufler wrote:
> Replace the osid field in the audit_names structure
> with a lsmblob structure. This accomodates the use
> of an lsmblob in security_audit_rule_match() and
> security_inode_getsecid().
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> Acked-by: Paul Moore <paul@paul-moore.com>
> ---
> kernel/audit.h | 2 +-
> kernel/auditsc.c | 22 ++++++++--------------
> 2 files changed, 9 insertions(+), 15 deletions(-)
>
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 316fac62d5f7..4af63e7dde17 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -82,7 +82,7 @@ struct audit_names {
> kuid_t uid;
> kgid_t gid;
> dev_t rdev;
> - u32 osid;
> + struct lsmblob lsmblob;
> struct audit_cap_data fcap;
> unsigned int fcap_ver;
> unsigned char type; /* record type */
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 231631f61550..6fe9f2525fc1 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -700,17 +700,16 @@ static int audit_filter_rules(struct task_struct *tsk,
> * lsmblob, which happens later in
> * this patch set.
> */
> - lsmblob_init(&blob, name->osid);
> result = security_audit_rule_match(
> - &blob,
> + &name->lsmblob,
> f->type,
> f->op,
> &f->lsm_rules);
> } else if (ctx) {
> list_for_each_entry(n, &ctx->names_list, list) {
> - lsmblob_init(&blob, n->osid);
> if (security_audit_rule_match(
> - &blob, f->type, f->op,
> + &n->lsmblob,
> + f->type, f->op,
> &f->lsm_rules)) {
> ++result;
> break;
> @@ -1589,13 +1588,12 @@ 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;
> + if (lsmblob_is_set(&n->lsmblob)) {
> 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 (security_secid_to_secctx(&n->lsmblob, &lsmctx,
> + LSMBLOB_FIRST)) {
> + audit_log_format(ab, " osid=?");

is there something better we can do here? This feels like a regression

> if (call_panic)
> *call_panic = 2;
> } else {
> @@ -2297,17 +2295,13 @@ 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 = lsmblob_first(&blob);
> + security_inode_getsecid(inode, &name->lsmblob);
> if (flags & AUDIT_INODE_NOEVAL) {
> name->fcap_ver = -1;
> return;