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: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 9269735..c1558ba 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -172,11 +172,11 @@
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 @@
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()
@@ -2017,16 +2018,14 @@
if (!parse_elf(&info, modname))
return;
- {
- char *tmp;
-
- /* strip trailing .o */
- tmp = NOFAIL(strdup(modname));
- tmp[strlen(tmp) - 2] = '\0';
- mod = new_module(tmp);
- free(tmp);
+ if (!strends(modname, ".o")) {
+ error("%s: filename must be suffixed with .o\n", modname);
+ return;
}
+ /* strip trailing .o */
+ mod = new_module(modname, strlen(modname) - strlen(".o"));
+
if (!mod->is_vmlinux) {
license = get_modinfo(&info, "license");
if (!license)
@@ -2488,7 +2487,7 @@
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);
