From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 21 Mar 2022 16:56:10 -0400 Subject: [PATCH] modules: Don't allocate space for non-allocable sections. Currently when loading grub modules, we allocate space for all sections, including those without SHF_ALLOC set. We then copy the sections that /do/ have SHF_ALLOC set into the allocated memory, leaving some of our allocation untouched forever. Additionally, on platforms with GOT fixups and trampolines, we currently compute alignment round-ups for the sections and sections with sh_size = 0. This patch removes the extra space from the allocation computation, and makes the allocation computation loop skip empty sections as the loading loop does. Signed-off-by: Peter Jones (cherry picked from commit 03215e342f552396ab08125ea769b1e166417ec1) --- grub-core/kern/dl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c index 9557254035..198867fa1b 100644 --- a/grub-core/kern/dl.c +++ b/grub-core/kern/dl.c @@ -289,6 +289,9 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e) i < e->e_shnum; i++, s = (const Elf_Shdr *)((const char *) s + e->e_shentsize)) { + if (s->sh_size == 0 || !(s->sh_flags & SHF_ALLOC)) + continue; + tsize = ALIGN_UP (tsize, s->sh_addralign) + s->sh_size; if (talign < s->sh_addralign) talign = s->sh_addralign;