On 2022-08-16 09:37, Steve Grubb wrote:
> Hello Richard,
>
> Although I have it working, I have some comments below that might improve
> things.
>
> On Tuesday, August 9, 2022 1:22:55 PM EDT Richard Guy Briggs wrote:
> > Currently the only type of fanotify info that is defined is an audit
> > rule number, but convert it to hex encoding to future-proof the field.
> >
> > Sample record:
> > type=FANOTIFY msg=audit(1659730979.839:284): resp=1 fan_type=0
> > fan_info=3F
> >
> > Suggested-by: Paul Moore <paul@xxxxxxxxxxxxxx>
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> > kernel/auditsc.c | 28 +++++++++++++++++++++-------
> > 1 file changed, 21 insertions(+), 7 deletions(-)
> >
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index f000fec52360..0f747015c577 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -2908,22 +2908,36 @@ void __audit_fanotify(u32 response, size_t len,
> > char *buf)
> >
> > if (!(len && buf)) {
> > audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY,
> > - "resp=%u fan_type=0 fan_info=?", response);
> > + "resp=%u fan_type=0 fan_info=3F", response); /* "?" */
> > return;
> > }
> > while (c >= sizeof(struct fanotify_response_info_header)) {
> > + struct audit_context *ctx = audit_context();
> > + struct audit_buffer *ab;
> > +
> > friar = (struct fanotify_response_info_audit_rule *)buf;
> > switch (friar->hdr.type) {
> > case FAN_RESPONSE_INFO_AUDIT_RULE:
> > if (friar->hdr.len < sizeof(*friar)) {
> > - audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY,
> > - "resp=%u fan_type=%u fan_info=(incomplete)",
> > - response, friar->hdr.type);
> > + ab = audit_log_start(ctx, GFP_KERNEL, AUDIT_FANOTIFY);
> > + if (ab) {
> > + audit_log_format(ab, "resp=%u fan_type=%u fan_info=",
> > + response, friar->hdr.type);
> > +#define INCOMPLETE "(incomplete)"
> > + audit_log_n_hex(ab, INCOMPLETE, sizeof(INCOMPLETE));
> > + audit_log_end(ab);
> > + }
> > return;
> > }
> > - audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY,
> > - "resp=%u fan_type=%u fan_info=%u",
> > - response, friar->hdr.type, friar->audit_rule);
> > + ab = audit_log_start(ctx, GFP_KERNEL, AUDIT_FANOTIFY);
> > + if (ab) {
> > + audit_log_format(ab, "resp=%u fan_type=%u fan_info=",
> > + response, friar->hdr.type);
> > + audit_log_n_hex(ab, (char *)&friar->audit_rule,
> > + sizeof(friar->audit_rule));
>
> One thing to point out, the structure has a member audit_rule. It is
> probably better to call it rule_number. This is because it has nothing to
> do with any actual audit rule. It is a rule number meant to be recorded by
> the audit system.
>
> Also, that member is a __u32 type. Hex encoding that directly gives back a
> __u32 when decoded - which is a bit unexpected since everything else is
> strings. It would be better to convert the u32 to a base 10 string and then
> hex encode that. A buffer of 12 bytes should be sufficient.
Sure, these seem reasonable.
> Thanks,
> -Steve
>
> > + audit_log_end(ab);
> > +
> > + }
> > }
> > c -= friar->hdr.len;
> > ib += friar->hdr.len;
>
>
>
>
- RGB
--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635
