2021-12-14 02:27:15

by Xiaoke Wang

Subject: [PATCH] tracing: check the return value of kstrndup()

From: Xiaoke Wang <[email protected]>

kstrndup() is a memory allocation-related function, it returns NULL when
some internal memory errors happen. It is better to check the return
value of it so to catch the memory error in time.

Signed-off-by: Xiaoke Wang <[email protected]>
---
kernel/trace/trace_probe.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 3ed2a3f..bb4605b 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -356,6 +356,8 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
return -EINVAL;
}
*pbuf = kstrndup(str, len - 1, GFP_KERNEL);
+ if (!*pbuf)
+ return -ENOMEM;
return 0;
}

--

2022-01-05 22:12:22

by Steven Rostedt

Subject: Re: [PATCH] tracing: check the return value of kstrndup()

Masami, can you ack this?

-- Steve


On Tue, 14 Dec 2021 10:26:46 +0800
[email protected] wrote:

> From: Xiaoke Wang <[email protected]>
>
> kstrndup() is a memory allocation-related function, it returns NULL when
> some internal memory errors happen. It is better to check the return
> value of it so to catch the memory error in time.
>
> Signed-off-by: Xiaoke Wang <[email protected]>
> ---
> kernel/trace/trace_probe.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 3ed2a3f..bb4605b 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -356,6 +356,8 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
> return -EINVAL;
> }
> *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
> + if (!*pbuf)
> + return -ENOMEM;
> return 0;
> }
>

2022-01-05 22:40:38

by Masami Hiramatsu (Google)

Subject: Re: [PATCH] tracing: check the return value of kstrndup()

On Wed, 5 Jan 2022 17:11:12 -0500
Steven Rostedt <[email protected]> wrote:

> Masami, can you ack this?

Yes, thanks for fowarding.

>
> -- Steve
>
>
> On Tue, 14 Dec 2021 10:26:46 +0800
> [email protected] wrote:
>
> > From: Xiaoke Wang <[email protected]>
> >
> > kstrndup() is a memory allocation-related function, it returns NULL when
> > some internal memory errors happen. It is better to check the return
> > value of it so to catch the memory error in time.

Thanks for fixing!

Acked-by: Masami Hiramatsu <[email protected]>
Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support")


> >
> > Signed-off-by: Xiaoke Wang <[email protected]>
> > ---
> > kernel/trace/trace_probe.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> > index 3ed2a3f..bb4605b 100644
> > --- a/kernel/trace/trace_probe.c
> > +++ b/kernel/trace/trace_probe.c
> > @@ -356,6 +356,8 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
> > return -EINVAL;
> > }
> > *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
> > + if (!*pbuf)
> > + return -ENOMEM;
> > return 0;
> > }
> >
>


--
Masami Hiramatsu <[email protected]>