Re: [PATCH] modpost: abort if a module name is too long

[Wanlong Gao]

Folks,

Any comments?


On 2017/5/20 15:46, Xie XiuQi wrote:
> From: Wanlong Gao <gaowanlong@xxxxxxxxxx>
> 
> Module name has a limited length, but currently the build system
> allows the build finishing even if the module name is too long.
> 
>   CC      /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
> /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2:
> warning: initializer-string for array of chars is too long [enabled by default]
>   .name = KBUILD_MODNAME,
>   ^
> 
> but it's merely a warning.
> 
> This patch adds the check of the module name length in modpost and stops
> the build properly.
> 
> Signed-off-by: Wanlong Gao <gaowanlong@xxxxxxxxxx>
> Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
> ---
>  scripts/mod/modpost.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> index 30d752a..db11c57 100644
> --- a/scripts/mod/modpost.c
> +++ b/scripts/mod/modpost.c
> @@ -2166,6 +2166,17 @@ static int add_versions(struct buffer *b, struct module *mod)
>  {
>  	struct symbol *s, *exp;
>  	int err = 0;
> +	const char *mod_name;
> +
> +	mod_name = strrchr(mod->name, '/');
> +	if (mod_name == NULL)
> +		mod_name = mod->name;
> +	else
> +		mod_name++;
> +	if (strlen(mod_name) >= MODULE_NAME_LEN) {
> +		merror("module name is too long [%s.ko]\n", mod->name);
> +		return 1;
> +	}
>  
>  	for (s = mod->unres; s; s = s->next) {
>  		exp = find_symbol(s->name);
>