Re: [PATCH v4 4/4] fanotify, audit: deliver fan_info as a hex-encoded string
On Tue, Aug 9, 2022 at 1:23 PM Richard Guy Briggs <rgb(a)redhat.com> 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(a)paul-moore.com>
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
kernel/auditsc.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
This needs to be squashed with patch 3/4; it's a user visible change
so we don't want someone backporting 3/4 without 4/4, especially when
it is part of the same patchset.
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); /*
"?" */
Please drop the trailing comment, it's not necessary and it makes the
code messier.
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));
Is the distinction between "?" and "(incomplete)" really that
important? I'm not going to go digging through all of the
audit_log_format() callers to check, but I believe there is precedence
for using "?" not only for when a value is missing, but when it is
bogus as well.
If we are really going to use "(incomplete)" here, let's do a better
job than defining a macro mid-function and only using it in one other
place - the line immediately below the definition. This is both ugly
and a little silly (especially when one considers that the macro name
is almost exactly the same as the string it replaces. If we must use
"(incomplete)" here, just ditch the macro; any conceptual arguments
about macros vs literals is largely rendered moot since there is only
one user.
+ 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));
+ audit_log_end(ab);
+
+ }
}
c -= friar->hdr.len;
ib += friar->hdr.len;
--
2.27.0
--
paul-moore.com