implement a union to pad out file_handle

Cases where name_to_handle_at is used allocated the full struct to be
MAX_HANDLE_SZ, and assigned this size to handle_bytes. This is wrong
since handle_bytes should describe the length of the flexible array
member and not the whole struct.

Define a union type which includes sufficient padding to allow
assignment of MAX_HANDLE_SZ to be correct.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libudev/util.h b/src/libudev/util.h
index 6510237e1e..4efa4e062a 100644
--- a/src/libudev/util.h
+++ b/src/libudev/util.h
@@ -19,6 +19,7 @@
 
 #pragma once
 
+#include <fcntl.h>
 #include <string.h>
 #include <time.h>
 #include <stdlib.h>
@@ -300,3 +301,8 @@ static inline void qsort_safe(void *base, size_t nmemb, size_t size,
 
 int proc_cmdline(char **ret);
 int getpeercred(int fd, struct ucred *ucred);
+
+union file_handle_union {
+        struct file_handle handle;
+        char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ];
+};