> On May 12, 2022, at 7:17 AM, Wan Jiabing <wanjiabing@xxxxxxxx> wrote:
>
> Fix following coccicheck warning:
> ./kernel/trace/bpf_trace.c:2488:12-20: WARNING opportunity for vmemdup_user
>
> Use vmemdup_user instead of kvmalloc and copy_from_user.
>
> Signed-off-by: Wan Jiabing <wanjiabing@xxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 1b0db8f78dc8..48fc97a6db50 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -2483,15 +2483,11 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
>
> ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
> if (ucookies) {
> - cookies = kvmalloc(size, GFP_KERNEL);
> - if (!cookies) {
> - err = -ENOMEM;
> + cookies = vmemdup_user(ucookies, size);
vmemdup_user() uses GFP_USER, so this is a behavior change.
Song
> + if (IS_ERR(cookies)) {
> + err = PTR_ERR(cookies);
> goto error_addrs;
> }
> - if (copy_from_user(cookies, ucookies, size)) {
> - err = -EFAULT;
> - goto error_cookies;
> - }
> }
>
> link = kzalloc(sizeof(*link), GFP_KERNEL);
> --
> 2.35.1
>
