Commit 8c9ce89c authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

modpost: simplify mod->name allocation 



mod->name is set to the ELF filename with the suffix ".o" stripped.

The current code calls strdup() and free() to manipulate the string,
but a simpler approach is to pass new_module() with the name length
subtracted by 2.

Also, check if the passed filename ends with ".o" before stripping it.

The current code blindly chops the suffix:

    tmp[strlen(tmp) - 2] = '\0'

It will cause buffer under-run if strlen(tmp) < 2;

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
parent b42d2306

scripts/mod/modpost.c

+12 −13
Original line number Diff line number Diff line
@@ -172,11 +172,11 @@ static struct module *find_module(const char *modname) 
	return NULL;

}



static struct module *new_module(const char *modname)

static struct module *new_module(const char *name, size_t namelen)

{

	struct module *mod;



	mod = NOFAIL(malloc(sizeof(*mod) + strlen(modname) + 1));

	mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));

	memset(mod, 0, sizeof(*mod));



	INIT_LIST_HEAD(&mod->exported_symbols);
@@ -184,8 +184,9 @@ static struct module *new_module(const char *modname) 
	INIT_LIST_HEAD(&mod->missing_namespaces);

	INIT_LIST_HEAD(&mod->imported_namespaces);



	strcpy(mod->name, modname);

	mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);

	memcpy(mod->name, name, namelen);

	mod->name[namelen] = '\0';

	mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);



	/*

	 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
@@ -2017,15 +2018,13 @@ static void read_symbols(const char *modname) 
	if (!parse_elf(&info, modname))

		return;



	{

		char *tmp;

	if (!strends(modname, ".o")) {

		error("%s: filename must be suffixed with .o\n", modname);

		return;

	}



	/* strip trailing .o */

		tmp = NOFAIL(strdup(modname));

		tmp[strlen(tmp) - 2] = '\0';

		mod = new_module(tmp);

		free(tmp);

	}

	mod = new_module(modname, strlen(modname) - strlen(".o"));



	if (!mod->is_vmlinux) {

		license = get_modinfo(&info, "license");
@@ -2488,7 +2487,7 @@ static void read_dump(const char *fname) 


		mod = find_module(modname);

		if (!mod) {

			mod = new_module(modname);

			mod = new_module(modname, strlen(modname));

			mod->from_dump = true;

		}

		s = sym_add_exported(symname, mod, gpl_only);