Re: [PATCH ghak64 V3] audit: add saddr_fam filter field

On Thu, May 9, 2019 at 8:02 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > 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; The f->val check looks better, thank you. However, I just noticed that it appears you've added two AUDIT_SADDR_FAM cases to the switch statement?

> 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: -- paul moore www.paul-moore.com