[PATCH ghak64 V3] audit: add saddr_fam filter field
Provide a method to filter out sockaddr and bind calls by network
address family.
Existing SOCKADDR records are listed for any network activity.
Implement the AUDIT_SADDR_FAM field selector to be able to classify or
limit records to specific network address families, such as AF_INET or
AF_INET6.
An example of a network record that is unlikely to be useful and flood
the logs:
type=SOCKADDR msg=audit(07/27/2017 12:18:27.019:845) : saddr={ fam=local
path=/var/run/nscd/socket }
type=SYSCALL msg=audit(07/27/2017 12:18:27.019:845) : arch=x86_64
syscall=connect success=no exit=ENOENT(No such file or directory) a0=0x3
a1=0x7fff229c4980 a2=0x6e a3=0x6 items=1 ppid=3301 pid=6145 auid=sgrubb
uid=sgrubb gid=sgrubb euid=sgrubb suid=sgrubb fsuid=sgrubb egid=sgrubb
sgid=sgrubb fsgid=sgrubb tty=pts3 ses=4 comm=bash exe=/usr/bin/bash
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
key=network-test
Please see the audit-testsuite PR at
https://github.com/linux-audit/audit-testsuite/pull/87
Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/64
Please see the github issue for the accompanying userspace support
https://github.com/linux-audit/audit-userspace/issues/93
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
Changelog:
v2:
- rebase on ghak73 v2
- check for valid range of saddr_fam value
v3:
- eliminate AF_UNSPEC check
include/uapi/linux/audit.h | 1 +
kernel/auditfilter.c | 5 +++++
kernel/auditsc.c | 5 +++++
3 files changed, 11 insertions(+)
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index a1280af20336..c89c6495983d 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -281,6 +281,7 @@
#define AUDIT_OBJ_GID 110
#define AUDIT_FIELD_COMPARE 111
#define AUDIT_EXE 112
+#define AUDIT_SADDR_FAM 113
#define AUDIT_ARG0 200
#define AUDIT_ARG1 (AUDIT_ARG0+1)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 5beb2244d5ba..df8a7d6184dc 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -387,6 +387,7 @@ static int audit_field_valid(struct audit_entry *entry, struct
audit_field *f)
case AUDIT_SUCCESS:
case AUDIT_INODE:
case AUDIT_SESSIONID:
+ case AUDIT_SADDR_FAM:
/* bit ops are only useful on syscall args */
if (f->op == Audit_bitmask || f->op == Audit_bittest)
return -EINVAL;
@@ -438,6 +439,10 @@ static int audit_field_valid(struct audit_entry *entry, struct
audit_field *f)
if (f->val > AUDIT_MAX_FIELD_COMPARE)
return -EINVAL;
break;
+ case AUDIT_SADDR_FAM:
+ if (f->val >= AF_MAX)
+ return -EINVAL;
+ break;
default:
break;
}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 4bd0ec60a0e8..aab364804b9b 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -623,6 +623,11 @@ static int audit_filter_rules(struct task_struct *tsk,
case AUDIT_LOGINUID_SET:
result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
break;
+ case AUDIT_SADDR_FAM:
+ if (ctx->sockaddr)
+ result = audit_comparator(ctx->sockaddr->ss_family,
+ f->op, f->val);
+ break;
case AUDIT_SUBJ_USER:
case AUDIT_SUBJ_ROLE:
case AUDIT_SUBJ_TYPE:
--
1.8.3.1