Messages in this thread | | | Date | Sun, 15 Sep 2013 18:26:41 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH] argv_split: Return NULL if argument contains nonon-whitespace. |
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On 09/15, Tetsuo Handa wrote: > > Oleg Nesterov wrote: > > > upon core dump because helper_argv[0] == NULL at > > > > > > helper_argv = argv_split(GFP_KERNEL, cn.corename, NULL); > > > call_usermodehelper_setup(helper_argv[0], ...); > > > > Are you sure? See above. > > > > Yes, I'm sure.
I thougt you meant that call_usermodehelper_setup() crashes. "See above" means that afaics it should crash in do_filp_open().
> execve(NULL) from user space is safe,
because it never does do_execve(NULL),
> but > do_execve(NULL) from kernel space is not safe.
Yes, this is clear.
> > Perhaps > > > > --- x/kernel/kmod.c > > +++ x/kernel/kmod.c > > @@ -571,6 +571,9 @@ int call_usermodehelper_exec(struct subp > > DECLARE_COMPLETION_ONSTACK(done); > > int retval = 0; > > > > + if (!sub_info->path) > > + return -EXXX; > > + > > helper_lock(); > > if (!khelper_wq || usermodehelper_disabled) { > > retval = -EBUSY; > > > > ? > > > > I'm OK with that.
OK,
Oleg.
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