Messages in this thread | | | Date | Sat, 28 Oct 2017 17:47:59 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v3 2/2] kprobes: initialize probed_mod to NULL |
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On Fri, 27 Oct 2017 17:23:15 +0800 Zhou Chengming <zhouchengming1@huawei.com> wrote:
> When check_kprobe_address_safe() return fail, the probed_mod > should be set to NULL, because no module refcount held. And we > initialize probed_mod to NULL in register_kprobe() for the same reason. >
Ok, it's a kind of hardening code but looks good to me.
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Thank you!
> Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> > --- > kernel/kprobes.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 1eeedac..a04588c 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1488,6 +1488,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > * its code to prohibit unexpected unloading. > */ > if (unlikely(!try_module_get(*probed_mod))) { > + *probed_mod = NULL; > ret = -ENOENT; > goto out; > } > @@ -1514,7 +1515,7 @@ int register_kprobe(struct kprobe *p) > { > int ret; > struct kprobe *old_p; > - struct module *probed_mod; > + struct module *probed_mod = NULL; > kprobe_opcode_t *addr; > > /* Adjust probe address from symbol */ > -- > 1.8.3.1 >
-- Masami Hiramatsu <mhiramat@kernel.org>
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