Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2021-03-10

The following pull-request contains BPF updates for your *net* tree.

We've added 8 non-merge commits during the last 5 day(s) which contain
a total of 11 files changed, 136 insertions(+), 17 deletions(-).

The main changes are:

1) Reject bogus use of vmlinux BTF as map/prog creation BTF, from Alexei Starovoitov.

2) Fix allocation failure splat in x86 JIT for large progs. Also fix overwriting
   percpu cgroup storage from tracing programs when nested, from Yonghong Song.

3) Fix rx queue retrieval in XDP for multi-queue veth, from Maciej Fijalkowski.

4) Fix bpf_check_mtu() helper API before freeze to have mtu_len as custom skb/xdp
   L3 input length, from Jesper Dangaard Brouer.

5) Fix inode_storage's lookup_elem return value upon having bad fd, from Tal Lossos.

6) Fix bpftool and libbpf cross-build on MacOS, from Georgi Valkov.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 10 insertions, 1 deletions

diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index 6639640523c0..b58b2efb9b43 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -109,7 +109,7 @@ static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key)
 	fd = *(int *)key;
 	f = fget_raw(fd);
 	if (!f)
-		return NULL;
+		return ERR_PTR(-EBADF);
 
 	sdata = inode_storage_lookup(f->f_inode, map, true);
 	fput(f);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c859bc46d06c..250503482cda 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -854,6 +854,11 @@ static int map_create(union bpf_attr *attr)
 			err = PTR_ERR(btf);
 			goto free_map;
 		}
+		if (btf_is_kernel(btf)) {
+			btf_put(btf);
+			err = -EACCES;
+			goto free_map;
+		}
 		map->btf = btf;
 
 		if (attr->btf_value_type_id) {
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c56e3fcb5f1a..4192a9e56654 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9056,6 +9056,10 @@ static int check_btf_info(struct bpf_verifier_env *env,
 	btf = btf_get_by_fd(attr->prog_btf_fd);
 	if (IS_ERR(btf))
 		return PTR_ERR(btf);
+	if (btf_is_kernel(btf)) {
+		btf_put(btf);
+		return -EACCES;
+	}
 	env->prog->aux->btf = btf;
 
 	err = check_btf_func(env, attr, uattr);