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Subject[PATCH ghak90 V8 13/16] audit: track container nesting
Date
Track the parent container of a container to be able to filter and
report nesting.

Now that we have a way to track and check the parent container of a
container, modify the contid field format to be able to report that
nesting using a carrat ("^") separator to indicate nesting. The
original field format was "contid=<contid>" for task-associated records
and "contid=<contid>[,<contid>[...]]" for network-namespace-associated
records. The new field format is
"contid=<contid>[^<contid>[...]][,<contid>[...]]".

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
include/linux/audit.h | 1 +
kernel/audit.c | 53 +++++++++++++++++++++++++++++++++++++++++++--------
kernel/audit.h | 1 +
kernel/auditfilter.c | 17 ++++++++++++++++-
kernel/auditsc.c | 2 +-
5 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index ed8d5b74758d..4272b468417a 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -109,6 +109,7 @@ struct audit_contobj {
struct task_struct *owner;
refcount_t refcount;
struct rcu_head rcu;
+ struct audit_contobj *parent;
};

struct audit_task_info {
diff --git a/kernel/audit.c b/kernel/audit.c
index ef8e07524c46..68be59d1a89b 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -251,6 +251,7 @@ static void _audit_contobj_put(struct audit_contobj *cont)
return;
if (refcount_dec_and_test(&cont->refcount)) {
put_task_struct(cont->owner);
+ _audit_contobj_put(cont->parent);
list_del_rcu(&cont->list);
kfree_rcu(cont, rcu);
}
@@ -492,6 +493,7 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
audit_netns_contid_add(new->net_ns, contid);
}

+void audit_log_contid(struct audit_buffer *ab, u64 contid);
/**
* audit_log_netns_contid_list - List contids for the given network namespace
* @net: the network namespace of interest
@@ -523,7 +525,7 @@ void audit_log_netns_contid_list(struct net *net, struct audit_context *context)
audit_log_format(ab, "contid=");
} else
audit_log_format(ab, ",");
- audit_log_format(ab, "%llu", cont->id);
+ audit_log_contid(ab, cont->id);
}
audit_log_end(ab);
out:
@@ -2311,6 +2313,36 @@ void audit_log_session_info(struct audit_buffer *ab)
audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
}

+void audit_log_contid(struct audit_buffer *ab, u64 contid)
+{
+ struct audit_contobj *cont = NULL, *prcont = NULL;
+ int h;
+
+ if (!audit_contid_valid(contid)) {
+ audit_log_format(ab, "%llu", contid);
+ return;
+ }
+ h = audit_hash_contid(contid);
+ rcu_read_lock();
+ list_for_each_entry_rcu(cont, &audit_contid_hash[h], list)
+ if (cont->id == contid) {
+ prcont = cont;
+ break;
+ }
+ if (!prcont) {
+ audit_log_format(ab, "%llu", contid);
+ goto out;
+ }
+ while (prcont) {
+ audit_log_format(ab, "%llu", prcont->id);
+ prcont = prcont->parent;
+ if (prcont)
+ audit_log_format(ab, "^");
+ }
+out:
+ rcu_read_unlock();
+}
+
/*
* audit_log_container_id - report container info
* @context: task or local context for record
@@ -2326,7 +2358,8 @@ void audit_log_container_id(struct audit_context *context, u64 contid)
ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER_ID);
if (!ab)
return;
- audit_log_format(ab, "contid=%llu", contid);
+ audit_log_format(ab, "contid=");
+ audit_log_contid(ab, contid);
audit_log_end(ab);
}
EXPORT_SYMBOL(audit_log_container_id);
@@ -2675,6 +2708,9 @@ int audit_set_contid(struct task_struct *task, u64 contid)
newcont->id = contid;
get_task_struct(current);
newcont->owner = current;
+ newcont->parent = _audit_contobj(newcont->owner);
+ if (newcont->parent)
+ _audit_contobj_hold(newcont->parent);
refcount_set(&newcont->refcount, 1);
spin_lock(&audit_contobj_list_lock);
list_add_rcu(&newcont->list, &audit_contid_hash[h]);
@@ -2705,9 +2741,10 @@ int audit_set_contid(struct task_struct *task, u64 contid)
if (!ab)
return rc;

- audit_log_format(ab,
- "op=set opid=%d contid=%llu old-contid=%llu",
- task_tgid_nr(task), contid, oldcontid);
+ audit_log_format(ab, "op=set opid=%d contid=", task_tgid_nr(task));
+ audit_log_contid(ab, contid);
+ audit_log_format(ab, " old-contid=");
+ audit_log_contid(ab, oldcontid);
audit_log_end(ab);
return rc;
}
@@ -2723,9 +2760,9 @@ void audit_log_container_drop(void)
if (!ab)
return;

- audit_log_format(ab, "op=drop opid=%d contid=%llu old-contid=%llu",
- task_tgid_nr(current), audit_get_contid(current),
- audit_get_contid(current));
+ audit_log_format(ab, "op=drop opid=%d contid=%llu old-contid=",
+ task_tgid_nr(current), AUDIT_CID_UNSET);
+ audit_log_contid(ab, audit_get_contid(current));
audit_log_end(ab);
}

diff --git a/kernel/audit.h b/kernel/audit.h
index 5e2f5c9820d8..de814fcbb38c 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -226,6 +226,7 @@ static inline int audit_hash_contid(u64 contid)
extern int audit_match_class(int class, unsigned syscall);
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_comparator64(const u64 left, const u32 op, const u64 right);
+extern int audit_contid_comparator(const u64 left, const u32 op, const u64 right);
extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
extern int parent_len(const char *path);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 9606f973fe33..1757896740e8 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1297,6 +1297,21 @@ int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
}
}

+int audit_contid_comparator(u64 left, u32 op, u64 right)
+{
+ struct audit_contobj *cont = NULL;
+ int h;
+ int result = 0;
+
+ h = audit_hash_contid(left);
+ list_for_each_entry_rcu(cont, &audit_contid_hash[h], list) {
+ result = audit_comparator64(cont->id, op, right);
+ if (result)
+ break;
+ }
+ return result;
+}
+
/**
* parent_len - find the length of the parent portion of a pathname
* @path: pathname of which to determine length
@@ -1388,7 +1403,7 @@ int audit_filter(int msgtype, unsigned int listtype)
f->op, f->val);
break;
case AUDIT_CONTID:
- result = audit_comparator64(audit_get_contid(current),
+ result = audit_contid_comparator(audit_get_contid(current),
f->op, f->val64);
break;
case AUDIT_MSGTYPE:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index a658fe775b86..6bf6d8b9dfd1 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -630,7 +630,7 @@ static int audit_filter_rules(struct task_struct *tsk,
f->op, f->val);
break;
case AUDIT_CONTID:
- result = audit_comparator64(audit_get_contid(tsk),
+ result = audit_contid_comparator(audit_get_contid(tsk),
f->op, f->val64);
break;
case AUDIT_SUBJ_USER:
--
1.8.3.1
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