binfmt_elf: Replace offsetof() with struct_size() in fill_note_info()

When dealing with structures containing flexible arrays, struct_size()
provides additional compile-time checks compared to offsetof(). This
enhances code robustness and reduces the risk of potential errors.

Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
Link: https://lore.kernel.org/r/20250813115058.635742-1-zhao.xichao@vivo.com
Signed-off-by: Kees Cook <kees@kernel.org>

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 264fba0d44bdf4328a889bff4e19771aedf9fe02..4aacf9c9cc2dfeeec740acebe70dbb479688022b 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1845,16 +1845,14 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
        /*
         * Allocate a structure for each thread.
         */
-       info->thread = kzalloc(offsetof(struct elf_thread_core_info,
-                                    notes[info->thread_notes]),
-                           GFP_KERNEL);
+       info->thread = kzalloc(struct_size(info->thread, notes, info->thread_notes),
+                              GFP_KERNEL);
        if (unlikely(!info->thread))
                return 0;
 
        info->thread->task = dump_task;
        for (ct = dump_task->signal->core_state->dumper.next; ct; ct = ct->next) {
-               t = kzalloc(offsetof(struct elf_thread_core_info,
-                                    notes[info->thread_notes]),
+               t = kzalloc(struct_size(t, notes, info->thread_notes),
                            GFP_KERNEL);
                if (unlikely(!t))
                        return 0;