Commit 435b08ec authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

bpf, test, cgroup: Use sk_{alloc,free} for test cases 



BPF test infra has some hacks in place which kzalloc() a socket and perform
minimum init via sock_net_set() and sock_init_data(). As a result, the sk's
skcd->cgroup is NULL since it didn't go through proper initialization as it
would have been the case from sk_alloc(). Rather than re-adding a NULL test
in sock_cgroup_ptr() just for this, use sk_{alloc,free}() pair for the test
socket. The latter also allows to get rid of the bpf_sk_storage_free() special
case.

Fixes: 8520e224 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode")
Fixes: b7a1848e ("bpf: add BPF_PROG_TEST_RUN support for flow dissector")
Fixes: 2cb494a3 ("bpf: add tests for direct packet access from CGROUP_SKB")
Reported-by: default avatar <syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com>
Reported-by: default avatar <syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Tested-by: default avatar <syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com>
Tested-by: default avatar <syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/bpf/20210927123921.21535-2-daniel@iogearbox.net
parent 78cc316e

net/bpf/test_run.c

+9 −5
Original line number Diff line number Diff line
@@ -552,6 +552,12 @@ static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb) 
	__skb->gso_segs = skb_shinfo(skb)->gso_segs;

}



static struct proto bpf_dummy_proto = {

	.name   = "bpf_dummy",

	.owner  = THIS_MODULE,

	.obj_size = sizeof(struct sock),

};



int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,

			  union bpf_attr __user *uattr)

{
@@ -596,20 +602,19 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 
		break;

	}



	sk = kzalloc(sizeof(struct sock), GFP_USER);

	sk = sk_alloc(net, AF_UNSPEC, GFP_USER, &bpf_dummy_proto, 1);

	if (!sk) {

		kfree(data);

		kfree(ctx);

		return -ENOMEM;

	}

	sock_net_set(sk, net);

	sock_init_data(NULL, sk);



	skb = build_skb(data, 0);

	if (!skb) {

		kfree(data);

		kfree(ctx);

		kfree(sk);

		sk_free(sk);

		return -ENOMEM;

	}

	skb->sk = sk;
@@ -682,8 +687,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 
	if (dev && dev != net->loopback_dev)

		dev_put(dev);

	kfree_skb(skb);

	bpf_sk_storage_free(sk);

	kfree(sk);

	sk_free(sk);

	kfree(ctx);

	return ret;

}