[PATCH v6 1/4] module: add module_elf_check_arch for module-specific checks
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2022-11-28 04:18:36
Subsystem:
module support, the rest · Maintainers:
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen, Linus Torvalds
The elf_check_arch() function is also used to test compatibility of usermode binaries. Kernel modules may have more specific requirements, for example powerpc would like to test for ABI version compatibility. Add a weak module_elf_check_arch() that defaults to true, and call it from elf_validity_check(). Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jessica Yu <jeyu@kernel.org> [np: added changelog, adjust name, rebase] Acked-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- include/linux/moduleloader.h | 3 +++ kernel/module/main.c | 10 ++++++++++ 2 files changed, 13 insertions(+)
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index 9e09d11ffe5b..7b4587a19189 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h@@ -13,6 +13,9 @@ * must be implemented by each architecture. */ +/* arch may override to do additional checking of ELF header architecture */ +bool module_elf_check_arch(Elf_Ehdr *hdr); + /* Adjust arch-specific sections. Return 0 on success. */ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d02d39c7174e..7b3f6fb0d428 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c@@ -1674,6 +1674,11 @@ static int elf_validity_check(struct load_info *info) info->hdr->e_machine); goto no_exec; } + if (!module_elf_check_arch(info->hdr)) { + pr_err("Invalid module architecture in ELF header: %u\n", + info->hdr->e_machine); + goto no_exec; + } if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { pr_err("Invalid ELF section header size\n"); goto no_exec;
@@ -2247,6 +2252,11 @@ static void flush_module_icache(const struct module *mod) (unsigned long)mod->core_layout.base + mod->core_layout.size); } +bool __weak module_elf_check_arch(Elf_Ehdr *hdr) +{ + return true; +} + int __weak module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings,
--
2.37.2