On Tue, Jan 17, 2023 at 4:14 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>
> This patch passes the full response so that the audit function can use all
> of it. The audit function was updated to log the additional information in
> the AUDIT_FANOTIFY record.
>
> 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.
> Hex encoding suggested by Paul Moore <paul@xxxxxxxxxxxxxx>.
>
> The {subj,obj}_trust values are {0,1,2}, corresponding to no, yes, unknown.
>
> Sample records:
> type=FANOTIFY msg=audit(1600385147.372:590): resp=2 fan_type=1 fan_info=3137 subj_trust=3 obj_trust=5
> type=FANOTIFY msg=audit(1659730979.839:284): resp=1 fan_type=0 fan_info=3F subj_trust=2 obj_trust=2
>
> Suggested-by: Steve Grubb <sgrubb@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/3075502.aeNJFYEL58@x2
> Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> ---
> fs/notify/fanotify/fanotify.c | 3 ++-
> include/linux/audit.h | 9 +++++----
> kernel/auditsc.c | 16 +++++++++++++---
> 3 files changed, 20 insertions(+), 8 deletions(-)
...
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d1fb821de104..3133c4175c15 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2877,10 +2878,19 @@ void __audit_log_kern_module(char *name)
> context->type = AUDIT_KERN_MODULE;
> }
>
> -void __audit_fanotify(u32 response)
> +void __audit_fanotify(u32 response, struct fanotify_response_info_audit_rule *friar)
> {
> - audit_log(audit_context(), GFP_KERNEL,
> - AUDIT_FANOTIFY, "resp=%u", response);
> + /* {subj,obj}_trust values are {0,1,2}: no,yes,unknown */
> + if (friar->hdr.type == FAN_RESPONSE_INFO_NONE) {
> + audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY,
> + "resp=%u fan_type=%u fan_info=3F subj_trust=2 obj_trust=2",
> + response, FAN_RESPONSE_INFO_NONE);
> + return;
> + }
> + audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY,
> + "resp=%u fan_type=%u fan_info=%X subj_trust=%u obj_trust=%u",
> + response, friar->hdr.type, friar->rule_number,
> + friar->subj_trust, friar->obj_trust);
> }
The only thing that comes to mind might be to convert the if-return
into a switch statement to make it a bit cleaner and easier to patch
in the future, but that is soooo far removed from any real concern
that I debated even mentioning it. I only bring it up in case the
"3F" discussion results in a respin, and even then I'm not going to
hold my ACK over something as silly as a if-return vs switch.
For clarity, this is what I was thinking:
void __audit_fanontify(...)
{
switch (type) {
case FAN_RESPONSE_INFO_NONE:
audit_log(...);
break;
default:
audit_log(...);
}
}
--
paul-moore.com
