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 <r...@redhat.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 -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit