From: Daniel Borkmann daniel@iogearbox.net
commit 435b08ec0094ac1e128afe6cfd0d9311a8c617a7 upstream.
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: 8520e224f547 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode") Fixes: b7a1848e8398 ("bpf: add BPF_PROG_TEST_RUN support for flow dissector") Fixes: 2cb494a36c98 ("bpf: add tests for direct packet access from CGROUP_SKB") Reported-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com Reported-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Alexei Starovoitov ast@kernel.org Tested-by: syzbot+664b58e9a40fbb2cec71@syzkaller.appspotmail.com Tested-by: syzbot+33f36d0754d4c5c0e102@syzkaller.appspotmail.com Link: https://lore.kernel.org/bpf/20210927123921.21535-2-daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/bpf/test_run.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
--- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -481,6 +481,12 @@ static void convert_skb_to___skb(struct __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) { @@ -525,20 +531,19 @@ int bpf_prog_test_run_skb(struct bpf_pro 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; @@ -611,8 +616,7 @@ out: 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; }