[PATCH 3/3] bpf: use vmemdup_user instead of kvmalloc and copy_from_user

[Wan Jiabing]

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);
+		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