Re: [PATCH v4 3/4] fanotify,audit: Allow audit to use the full permission event response

On Tue, Aug 9, 2022 at 1:23 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > This patch passes the full value 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. The following is an example of the new record > format: > > type=FANOTIFY msg=audit(1600385147.372:590): resp=2 fan_type=1 fan_info=17 > > Suggested-by: Steve Grubb <sgrubb(a)redhat.com&gt; > Link: https://lore.kernel.org/r/3075502.aeNJFYEL58@x2 > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > --- > fs/notify/fanotify/fanotify.c | 3 ++- > include/linux/audit.h | 9 +++++---- > kernel/auditsc.c | 31 ++++++++++++++++++++++++++++--- > 3 files changed, 35 insertions(+), 8 deletions(-) You've hopefully already seen the kernel test robot build warning, so I won't bring that up again, but a few comments below ...

> diff --git a/kernel/auditsc.c b/kernel/auditsc.c > index 433418d73584..f000fec52360 100644 > --- a/kernel/auditsc.c > +++ b/kernel/auditsc.c > @@ -64,6 +64,7 @@ > #include <uapi/linux/limits.h> > #include <uapi/linux/netfilter/nf_tables.h> > #include <uapi/linux/openat2.h> // struct open_how > +#include <uapi/linux/fanotify.h> > > #include "audit.h" > > @@ -2899,10 +2900,34 @@ void __audit_log_kern_module(char *name) > context->type = AUDIT_KERN_MODULE; > } > > -void __audit_fanotify(u32 response) > +void __audit_fanotify(u32 response, size_t len, char *buf) > { > - audit_log(audit_context(), GFP_KERNEL, > - AUDIT_FANOTIFY, "resp=%u", response); > + struct fanotify_response_info_audit_rule *friar; > + size_t c = len; > + char *ib = buf; > + > + if (!(len && buf)) { > + audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY, > + "resp=%u fan_type=0 fan_info=?", response); > + return; > + } > + while (c >= sizeof(struct fanotify_response_info_header)) { > + friar = (struct fanotify_response_info_audit_rule *)buf; Since the only use of this at the moment is the fanotify_response_info_rule, why not pass the fanotify_response_info_rule struct directly into this function? We can always change it if we need to in the future without affecting userspace, and it would simplify the code.

> + 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); > + return; > + } > + audit_log(audit_context(), GFP_KERNEL, AUDIT_FANOTIFY, > + "resp=%u fan_type=%u fan_info=%u", > + response, friar->hdr.type, friar->audit_rule); > + } > + c -= friar->hdr.len; > + ib += friar->hdr.len; > + } > } > > void __audit_tk_injoffset(struct timespec64 offset) paul-moore.com