On Thu, Oct 17, 2024 at 09:48:18AM -0700, Kees Cook wrote:
> On Thu, Oct 17, 2024 at 09:23:25AM -0700, Kees Cook wrote:
> > On Thu, Oct 17, 2024 at 09:07:13AM -0700, Kees Cook wrote:
> > > Something in the .config is causing the error. (!?) I will start a
> > > CONFIG bisect...
> >
> > Well, I did a code bisect first, and it reported this which makes _no_
> > sense:
> > 8afd8c8faa24 ("lsm: remove lsm_prop scaffolding")
> >
> > O_o
>
> Looks like a GCC inlining bug. If I query the size of the destination
> buffer before calling strscpy the warning magically vanishes. :|
>
> Lovely. I will see if I can construct a work-around.
I am extremely bothered that this fixes it:
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index bc052b4b5a1d..891f4294361d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2728,8 +2728,8 @@ void __audit_ptrace(struct task_struct *t)
context->target_auid = audit_get_loginuid(t);
context->target_uid = task_uid(t);
context->target_sessionid = audit_get_sessionid(t);
- security_task_getlsmprop_obj(t, &context->target_ref);
strscpy(context->target_comm, t->comm);
+ security_task_getlsmprop_obj(t, &context->target_ref);
}
/**
@@ -2755,8 +2755,8 @@ int audit_signal_info_syscall(struct task_struct *t)
ctx->target_auid = audit_get_loginuid(t);
ctx->target_uid = t_uid;
ctx->target_sessionid = audit_get_sessionid(t);
- security_task_getlsmprop_obj(t, &ctx->target_ref);
strscpy(ctx->target_comm, t->comm);
+ security_task_getlsmprop_obj(t, &ctx->target_ref);
return 0;
}
I will continue trying to figure out why GCC is getting confused here,
but in the meantime, perhaps this is a viable workaround?
--
Kees Cook
