From e9517aedd34f340bbaea55cd773d6f0e711b0001 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Mon, 11 Aug 2025 20:53:16 -0700
Subject: [PATCH] KernelUtils: make failure to call & parse uname abort
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

In practice this is already the case... If uname() execution
fails, or we fail to parse the result, we won't pass the
4.9+ required check in NetBpfLoad, which is required on S+,
and mainline no longer supports anything <S anyway.

We don't require subversion as technically "4.9" (ie. 4.9.0)
is enough for almost all usecases, although in practice I would
expect there will always be an LTS subversion present.

Test: TreeHugger
Flag: EXEMPT mainline
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I66a5eba5c7bcf9bd51997db93c0fefc8104945eb
---
 bpf/headers/include/bpf/KernelUtils.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/bpf/headers/include/bpf/KernelUtils.h b/bpf/headers/include/bpf/KernelUtils.h
index 7bdef5af39..f2b0be1caa 100644
--- a/bpf/headers/include/bpf/KernelUtils.h
+++ b/bpf/headers/include/bpf/KernelUtils.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/personality.h>
 #include <sys/utsname.h>
@@ -28,12 +29,12 @@ namespace bpf {
 
 static inline unsigned uncachedKernelVersion() {
     struct utsname buf;
-    if (uname(&buf)) return 0;
+    if (uname(&buf)) abort();
 
     unsigned kver_major = 0;
     unsigned kver_minor = 0;
     unsigned kver_sub = 0;
-    (void)sscanf(buf.release, "%u.%u.%u", &kver_major, &kver_minor, &kver_sub);
+    if (sscanf(buf.release, "%u.%u.%u", &kver_major, &kver_minor, &kver_sub) < 2) abort();
     return KVER(kver_major, kver_minor, kver_sub);
 }