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Message-Id: <1d793e2fc60650de4bbc9f4bde3c736c94efe9a1.1593198710.git.rgb@redhat.com>
Date: Sat, 27 Jun 2020 09:20:45 -0400
From: Richard Guy Briggs <rgb@...hat.com>
To: containers@...ts.linux-foundation.org, linux-api@...r.kernel.org,
Linux-Audit Mailing List <linux-audit@...hat.com>,
linux-fsdevel@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
netdev@...r.kernel.org, netfilter-devel@...r.kernel.org
Cc: Paul Moore <paul@...l-moore.com>, sgrubb@...hat.com,
omosnace@...hat.com, dhowells@...hat.com, simo@...hat.com,
eparis@...isplace.org, serge@...lyn.com, ebiederm@...ssion.com,
nhorman@...driver.com, dwalsh@...hat.com, mpatel@...hat.com,
Richard Guy Briggs <rgb@...hat.com>
Subject: [PATCH ghak90 V9 12/13] audit: track container nesting
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 ("^") modifier 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@...hat.com>
---
include/linux/audit.h | 1 +
kernel/audit.c | 60 ++++++++++++++++++++++++++++++++++++++++++---------
kernel/audit.h | 2 ++
kernel/auditfilter.c | 17 ++++++++++++++-
kernel/auditsc.c | 2 +-
5 files changed, 70 insertions(+), 12 deletions(-)
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 304fbb7c3c5b..025b52ae8422 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -115,6 +115,7 @@ struct audit_contobj {
refcount_t refcount;
refcount_t sigflag;
struct rcu_head rcu;
+ struct audit_contobj *parent;
};
struct audit_task_info {
diff --git a/kernel/audit.c b/kernel/audit.c
index efa65ec01239..aaf74702e993 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -221,6 +221,7 @@ struct audit_reply {
void audit_netns_contid_add(struct net *net, struct audit_contobj *cont);
void audit_netns_contid_del(struct net *net, struct audit_contobj *cont);
+void audit_log_contid(struct audit_buffer *ab, struct audit_contobj *cont);
void __init audit_task_init(void)
{
@@ -277,6 +278,7 @@ static void _audit_contobj_put_sig(struct audit_contobj *cont)
refcount_set(&cont->sigflag, 0);
if (!refcount_read(&cont->refcount)) {
put_task_struct(cont->owner);
+ _audit_contobj_put(cont->parent);
list_del_rcu(&cont->list);
kfree_rcu(cont, rcu);
}
@@ -574,7 +576,7 @@ 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->obj->id);
+ audit_log_contid(ab, cont->obj);
}
audit_log_end(ab);
out:
@@ -1747,7 +1749,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
kfree(sig_data);
break;
case AUDIT_SIGNAL_INFO2: {
+ char *contidstr = NULL;
unsigned int contidstrlen = 0;
+ struct audit_contobj *cont = audit_sig_cid;
len = 0;
if (audit_sig_sid) {
@@ -1757,13 +1761,27 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
return err;
}
if (audit_sig_cid) {
- contidstr = kmalloc(21, GFP_KERNEL);
+ contidstr = kmalloc(AUDIT_MESSAGE_TEXT_MAX, GFP_KERNEL);
if (!contidstr) {
if (audit_sig_sid)
security_release_secctx(ctx, len);
return -ENOMEM;
}
- contidstrlen = scnprintf(contidstr, 20, "%llu", audit_sig_cid->id);
+ rcu_read_lock();
+ while (cont) {
+ if (cont->parent)
+ contidstrlen += scnprintf(contidstr,
+ AUDIT_MESSAGE_TEXT_MAX -
+ contidstrlen,
+ "%llu,^", cont->id);
+ else
+ contidstrlen += scnprintf(contidstr,
+ AUDIT_MESSAGE_TEXT_MAX -
+ contidstrlen,
+ "%llu", cont->id);
+ cont = cont->parent;
+ }
+ rcu_read_unlock();
}
sig_data2 = kmalloc(sizeof(*sig_data2) + contidstrlen + len, GFP_KERNEL);
if (!sig_data2) {
@@ -2444,6 +2462,23 @@ 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, struct audit_contobj *cont)
+{
+ if (!cont) {
+ audit_log_format(ab, "-1");
+ return;
+ }
+ rcu_read_lock();
+ while (cont) {
+ if (cont->parent)
+ audit_log_format(ab, "%llu,^", cont->id);
+ else
+ audit_log_format(ab, "%llu", cont->id);
+ cont = cont->parent;
+ }
+ rcu_read_unlock();
+}
+
/*
* audit_log_container_id - report container info
* @context: task or local context for record
@@ -2460,7 +2495,8 @@ void audit_log_container_id(struct audit_context *context,
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, cont);
audit_log_end(ab);
}
EXPORT_SYMBOL(audit_log_container_id);
@@ -2810,6 +2846,7 @@ int audit_set_contid(struct task_struct *task, u64 contid)
INIT_LIST_HEAD(&newcont->list);
newcont->id = contid;
newcont->owner = get_task_struct(current);
+ newcont->parent = _audit_contobj_get(newcont->owner);
refcount_set(&newcont->refcount, 1);
list_add_rcu(&newcont->list,
&audit_contid_hash[h]);
@@ -2828,6 +2865,7 @@ int audit_set_contid(struct task_struct *task, u64 contid)
audit_netns_contid_add(net, newcont);
}
conterror:
+ rcu_read_unlock();
task_unlock(task);
if (!audit_enabled)
@@ -2837,12 +2875,13 @@ 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, oldcont ? oldcont->id : -1);
+ audit_log_format(ab, "op=set opid=%d contid=%llu old-contid=",
+ task_tgid_nr(task), contid);
+ audit_log_contid(ab, oldcont);
+ audit_log_end(ab);
+ rcu_read_lock();
_audit_contobj_put(oldcont);
rcu_read_unlock();
- audit_log_end(ab);
return rc;
}
@@ -2859,8 +2898,9 @@ void audit_log_container_drop(void)
ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONTAINER_OP);
if (!ab)
goto out;
- audit_log_format(ab, "op=drop opid=%d contid=%llu old-contid=%llu",
- task_tgid_nr(current), cont->id, cont->id);
+ audit_log_format(ab, "op=drop opid=%d contid=%llu old-contid=",
+ task_tgid_nr(current), AUDIT_CID_UNSET);
+ audit_log_contid(ab, cont);
audit_log_end(ab);
out:
rcu_read_unlock();
diff --git a/kernel/audit.h b/kernel/audit.h
index 34d8ec4bc6ef..7bea5b51124b 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -229,6 +229,8 @@ 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 d812698efc1d..981c72a8b863 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1302,6 +1302,21 @@ 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
@@ -1393,7 +1408,7 @@ 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 baa5709590b4..9198857ac721 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -641,7 +641,7 @@ 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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