[ghak90,V7,18/21] audit: track container nesting

Submitted by Richard Guy Briggs on Sept. 19, 2019, 1:22 a.m.

Details

Message ID a6b00624ac746bc0df9dd0044311b8364374b25b.1568834525.git.rgb@redhat.com
State New
Series "audit: implement container identifier"
Headers show

Commit Message

Richard Guy Briggs Sept. 19, 2019, 1:22 a.m.
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, fixup other patches, or squash all nesting fixes together.

fixup! audit: add container id
fixup! audit: log drop of contid on exit of last task
fixup! audit: log container info of syscalls
fixup! audit: add containerid filtering
fixup! audit: NETFILTER_PKT: record each container ID associated with a netNS
fixup! audit: convert to contid list to check for orch/engine ownership softirq (for netfilter) audit: protect contid list lock from softirq

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 include/linux/audit.h |  1 +
 kernel/audit.c        | 67 ++++++++++++++++++++++++++++++++++++++++++---------
 kernel/audit.h        |  3 +++
 kernel/auditfilter.c  | 20 ++++++++++++++-
 kernel/auditsc.c      |  2 +-
 5 files changed, 79 insertions(+), 14 deletions(-)

Patch hide | download patch | download mbox

diff --git a/include/linux/audit.h b/include/linux/audit.h
index dcd92f964120..1ce27af686ea 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -110,6 +110,7 @@  struct audit_cont {
 	struct task_struct	*owner;
 	refcount_t              refcount;
 	struct rcu_head         rcu;
+	struct audit_cont	*parent;
 };
 
 struct audit_task_info {
diff --git a/kernel/audit.c b/kernel/audit.c
index 9e82de13d2eb..848fd1c8c579 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -213,7 +213,7 @@  struct audit_reply {
 
 static struct kmem_cache *audit_task_cache;
 
-static DEFINE_SPINLOCK(audit_contid_list_lock);
+DEFINE_SPINLOCK(audit_contid_list_lock);
 
 void __init audit_task_init(void)
 {
@@ -275,6 +275,7 @@  void audit_free(struct task_struct *tsk)
 {
 	struct audit_task_info *info = tsk->audit;
 	struct nsproxy *ns = tsk->nsproxy;
+	unsigned long flags;
 
 	audit_free_syscall(tsk);
 	if (ns)
@@ -282,9 +283,9 @@  void audit_free(struct task_struct *tsk)
 	/* Freeing the audit_task_info struct must be performed after
 	 * audit_log_exit() due to need for loginuid and sessionid.
 	 */
-	spin_lock(&audit_contid_list_lock); 
+	spin_lock_irqsave(&audit_contid_list_lock, flags); 
 	audit_cont_put(tsk->audit->cont);
-	spin_unlock(&audit_contid_list_lock); 
+	spin_unlock_irqrestore(&audit_contid_list_lock, flags); 
 	info = tsk->audit;
 	tsk->audit = NULL;
 	kmem_cache_free(audit_task_cache, info);
@@ -450,6 +451,7 @@  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
@@ -481,7 +483,7 @@  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:
@@ -2371,6 +2373,36 @@  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_cont *cont = NULL;
+	struct audit_cont *prcont = NULL;
+	int h;
+	unsigned long flags;
+
+	if (!audit_contid_valid(contid)) {
+		audit_log_format(ab, "%llu", contid);
+		return;
+	}
+	h = audit_hash_contid(contid);
+	spin_lock_irqsave(&audit_contid_list_lock, flags);
+	list_for_each_entry_rcu(cont, &audit_contid_hash[h], list)
+		if (cont->id == contid)
+			prcont = cont;
+	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:
+	spin_unlock_irqrestore(&audit_contid_list_lock, flags);
+}
+
 /*
  * audit_log_container_id - report container info
  * @context: task or local context for record
@@ -2386,7 +2418,8 @@  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);
@@ -2648,6 +2681,7 @@  void audit_cont_put(struct audit_cont *cont)
 		return;
 	if (refcount_dec_and_test(&cont->refcount)) {
 		put_task_struct(cont->owner);
+		audit_cont_put(cont->parent);
 		list_del_rcu(&cont->list);
 		kfree_rcu(cont, rcu);
 		audit_contid_count--;
@@ -2732,8 +2766,9 @@  int audit_set_contid(struct task_struct *task, u64 contid)
 		struct audit_cont *cont = NULL;
 		struct audit_cont *newcont = NULL;
 		int h = audit_hash_contid(contid);
+		unsigned long flags;
 
-		spin_lock(&audit_contid_list_lock);
+		spin_lock_irqsave(&audit_contid_list_lock, flags);
 		list_for_each_entry_rcu(cont, &audit_contid_hash[h], list)
 			if (cont->id == contid) {
 				/* task injection to existing container */
@@ -2757,6 +2792,9 @@  int audit_set_contid(struct task_struct *task, u64 contid)
 				newcont->id = contid;
 				get_task_struct(current);
 				newcont->owner = current;
+				newcont->parent = audit_cont(newcont->owner);
+				if (newcont->parent)
+					refcount_inc(&newcont->parent->refcount);
 				refcount_set(&newcont->refcount, 1);
 				list_add_rcu(&newcont->list, &audit_contid_hash[h]);
 				audit_contid_count++;
@@ -2768,7 +2806,7 @@  int audit_set_contid(struct task_struct *task, u64 contid)
 		task->audit->cont = newcont;
 		audit_cont_put(oldcont);
 conterror:
-		spin_unlock(&audit_contid_list_lock);
+		spin_unlock_irqrestore(&audit_contid_list_lock, flags);
 	}
 	if (!rc) {
 		if (audit_contid_valid(oldcontid))
@@ -2786,9 +2824,12 @@  int audit_set_contid(struct task_struct *task, u64 contid)
 
 	uid = from_kuid(&init_user_ns, task_uid(current));
 	tty = audit_get_tty();
+	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_format(ab,
-			 "op=set opid=%d contid=%llu old-contid=%llu pid=%d uid=%u auid=%u tty=%s ses=%u",
-			 task_tgid_nr(task), contid, oldcontid,
+			 " pid=%d uid=%u auid=%u tty=%s ses=%u",
 			 task_tgid_nr(current), uid,
 			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
 			 tty ? tty_name(tty) : "(none)",
@@ -2819,10 +2860,12 @@  void audit_log_container_drop(void)
 
 	uid = from_kuid(&init_user_ns, task_uid(current));
 	tty = audit_get_tty();
+	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_format(ab,
-			 "op=drop opid=%d contid=%llu old-contid=%llu pid=%d uid=%u auid=%u tty=%s ses=%u",
-			 task_tgid_nr(current), audit_get_contid(current),
-			 audit_get_contid(current), task_tgid_nr(current), uid,
+			 " pid=%d uid=%u auid=%u tty=%s ses=%u",
+			 task_tgid_nr(current), uid,
 			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
 			 tty ? tty_name(tty) : "(none)",
        			 audit_get_sessionid(current));
diff --git a/kernel/audit.h b/kernel/audit.h
index 25732fbc47a4..89b7de323c13 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -220,6 +220,8 @@  static inline int audit_hash_contid(u64 contid)
 	return (contid & (AUDIT_CONTID_BUCKETS-1));
 }
 
+extern spinlock_t audit_contid_list_lock;
+
 extern int audit_contid_count;
 
 #define AUDIT_CONTID_COUNT	1 << 16
@@ -235,6 +237,7 @@  struct audit_contid_status {
 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..513d57d03637 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1297,6 +1297,24 @@  int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
 	}
 }
 
+int audit_contid_comparator(u64 left, u32 op, u64 right)
+{
+	struct audit_cont *cont = NULL;
+	int h;
+	int result = 0;
+	unsigned long flags;
+
+	h = audit_hash_contid(left);
+	spin_lock_irqsave(&audit_contid_list_lock, flags);
+	list_for_each_entry_rcu(cont, &audit_contid_hash[h], list) {
+		result = audit_comparator64(cont->id, op, right);
+		if (result)
+			break;
+	}
+	spin_unlock_irqrestore(&audit_contid_list_lock, flags);
+	return result;
+}
+
 /**
  * parent_len - find the length of the parent portion of a pathname
  * @path: pathname of which to determine length
@@ -1388,7 +1406,7 @@  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:

Comments

Paul Moore Oct. 11, 2019, 12:40 a.m.
On Wed, Sep 18, 2019 at 9:27 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> 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, fixup other patches, or squash all nesting fixes together.
>
> fixup! audit: add container id
> fixup! audit: log drop of contid on exit of last task
> fixup! audit: log container info of syscalls
> fixup! audit: add containerid filtering
> fixup! audit: NETFILTER_PKT: record each container ID associated with a netNS
> fixup! audit: convert to contid list to check for orch/engine ownership softirq (for netfilter) audit: protect contid list lock from softirq
>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  include/linux/audit.h |  1 +
>  kernel/audit.c        | 67 ++++++++++++++++++++++++++++++++++++++++++---------
>  kernel/audit.h        |  3 +++
>  kernel/auditfilter.c  | 20 ++++++++++++++-
>  kernel/auditsc.c      |  2 +-
>  5 files changed, 79 insertions(+), 14 deletions(-)

This is my last comment of the patchset because this is where it
starts to get a little weird.  I know we've talked about fixup!
patches some in the past, but perhaps I didn't do a very good job
communicating my poin; let me try again.

Submitting a fixup patch is okay if you've already posted a (lengthy)
patchset and there was a small nit that someone uncovered that needed
to be fixed prior to merging, assuming everyone (this includes the
reviewer, the patch author, and the maintainer) is okay with the
author posting the fix as fixup! patch then go for it.  Done this way,
fixup patches can save a lot of development, testing, and review time.
However, in my opinion it is wrong to submit a patchset that has fixup
patches as part of the original posting.  In this case fixup patches
have the opposite effect: the patchset becomes more complicated,
reviews take longer, and the likelihood of missing important details
increases.

When in doubt, don't submit separate fixup patches, fold them into the
original patches instead.

--
paul moore
www.paul-moore.com