Re: [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&gt; --- 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: