bpf: test_run: Fix overflow in bpf_test_finish frags parsing

This place also uses signed min_t and passes this singed int to
copy_to_user (which accepts unsigned argument). I don't think
there is an issue, but let's be consistent.

Fixes: 7855e0db150ad ("bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220204235849.14658-2-sdf@google.com

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 5819a7a..cb150f7 100644 (file)
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -154,7 +154,8 @@ static int bpf_test_finish(const union bpf_attr *kattr,
                        goto out;
 
                if (sinfo) {
-                       int i, offset = len, data_len;
+                       int i, offset = len;
+                       u32 data_len;
 
                        for (i = 0; i < sinfo->nr_frags; i++) {
                                skb_frag_t *frag = &sinfo->frags[i];
@@ -164,7 +165,7 @@ static int bpf_test_finish(const union bpf_attr *kattr,
                                        break;
                                }
 
-                               data_len = min_t(int, copy_size - offset,
+                               data_len = min_t(u32, copy_size - offset,
                                                 skb_frag_size(frag));
 
                                if (copy_to_user(data_out + offset,