From a9e742489ae4db42352796e985abcaf57edb745e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20T=C3=B6rnblom?= <john.tornblom@gmail.com>
Date: Sun, 2 Aug 2026 16:08:19 +0200
Subject: [PATCH] crt: fix potential bug in designated initializers with union
 members

---
 crt/kernel.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/crt/kernel.c b/crt/kernel.c
index 1a6a0ca..0979fee 100644
--- a/crt/kernel.c
+++ b/crt/kernel.c
@@ -502,9 +502,7 @@ __kernel_init(payload_args_t* args) {
  **/
 static int
 kernel_write(unsigned long kaddr, void* data, unsigned long len) {
-  kernel_pipebuf_t buf = {
-    .vbuf.kaddr = kaddr
-  };
+  kernel_pipebuf_t buf = {0};
 
   // sanity check for invalid kernel pointers
   if(!(kaddr & 0xffff000000000000)) {
@@ -512,6 +510,8 @@ kernel_write(unsigned long kaddr, void* data, unsigned long len) {
     return -1;
   }
 
+  buf.vbuf.kaddr = kaddr;
+
   if(__crt_syscall(SYS_setsockopt, MASTER_SOCK, IPPROTO_IPV6, IPV6_PKTINFO,
 		   &buf, sizeof(buf))) {
     return -1;
@@ -528,15 +528,15 @@ kernel_write(unsigned long kaddr, void* data, unsigned long len) {
 
 int
 kernel_copyin(const void *uaddr, unsigned long kaddr, unsigned long len) {
-  kernel_pipebuf_t buf = {
-    .flags.reserved = 0x40000000
-  };
+  kernel_pipebuf_t buf = {0};
 
   if(!kaddr || !uaddr || !len) {
     SET_ERRNO(EINVAL);
     return -1;
   }
 
+  buf.flags.reserved = 0x40000000;
+
   if(kernel_write(pipe_addr, &buf, sizeof(buf))) {
     return -1;
   }
@@ -559,16 +559,16 @@ kernel_copyin(const void *uaddr, unsigned long kaddr, unsigned long len) {
 
 int
 kernel_copyout(unsigned long kaddr, void *uaddr, unsigned long len) {
-  kernel_pipebuf_t buf = {
-    .flags.cnt = 0x40000000,
-    .flags.in = 0x40000000,
-  };
+  kernel_pipebuf_t buf = {0};
 
   if(!kaddr || !uaddr || !len) {
     SET_ERRNO(EINVAL);
     return -1;
   }
 
+  buf.flags.cnt = 0x40000000;
+  buf.flags.in = 0x40000000;
+
   if(kernel_write(pipe_addr, &buf, sizeof(buf))) {
     return -1;
   }