Re: [PATCH -next 1/3] fail_function: Switch to memdup_user_nul() helper

From: Google
Date: Mon Sep 12 2022 - 05:37:49 EST


On Fri, 26 Aug 2022 15:33:35 +0800
Yang Yingliang <yangyingliang@xxxxxxxxxx> wrote:

> Use memdup_user_nul() helper instead of open-coding to
> simplify the code.
>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>

Looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Thank you!

> ---
> kernel/fail_function.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/fail_function.c b/kernel/fail_function.c
> index 60dc825ecc2b..03643e33e4c3 100644
> --- a/kernel/fail_function.c
> +++ b/kernel/fail_function.c
> @@ -247,15 +247,11 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
> /* cut off if it is too long */
> if (count > KSYM_NAME_LEN)
> count = KSYM_NAME_LEN;
> - buf = kmalloc(count + 1, GFP_KERNEL);
> - if (!buf)
> - return -ENOMEM;
>
> - if (copy_from_user(buf, buffer, count)) {
> - ret = -EFAULT;
> - goto out_free;
> - }
> - buf[count] = '\0';
> + buf = memdup_user_nul(buffer, count);
> + if (IS_ERR(buf))
> + return PTR_ERR(buf);
> +
> sym = strstrip(buf);
>
> mutex_lock(&fei_lock);
> @@ -308,7 +304,6 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
> }
> out:
> mutex_unlock(&fei_lock);
> -out_free:
> kfree(buf);
> return ret;
> }
> --
> 2.25.1
>


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>