diff options
| author | Lorenz Bauer <lmb@isovalent.com> | 2023-08-15 09:53:41 +0100 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-08-15 13:57:51 -0700 |
| commit | 8897562f67b3e61ad736cd5c9f307447d33280e4 (patch) | |
| tree | d407c79392c986d17b4b16d9df68bcc4edbe31f1 | |
| parent | dda770407b817a7cfa72517905857f489cfc5e59 (diff) | |
| download | nf-next-8897562f67b3e61ad736cd5c9f307447d33280e4.tar.gz | |
net: Fix slab-out-of-bounds in inet[6]_steal_sock
Kumar reported a KASAN splat in tcp_v6_rcv:
bash-5.2# ./test_progs -t btf_skc_cls_ingress
...
[ 51.810085] BUG: KASAN: slab-out-of-bounds in tcp_v6_rcv+0x2d7d/0x3440
[ 51.810458] Read of size 2 at addr ffff8881053f038c by task test_progs/226
The problem is that inet[6]_steal_sock accesses sk->sk_protocol without
accounting for request or timewait sockets. To fix this we can't just
check sock_common->skc_reuseport since that flag is present on timewait
sockets.
Instead, add a fullsock check to avoid the out of bands access of sk_protocol.
Fixes: 9c02bec95954 ("bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign")
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230815-bpf-next-v2-1-95126eaa4c1b@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
| -rw-r--r-- | include/net/inet6_hashtables.h | 2 | ||||
| -rw-r--r-- | include/net/inet_hashtables.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h index 284b5ce7205d92..533a7337865a43 100644 --- a/include/net/inet6_hashtables.h +++ b/include/net/inet6_hashtables.h @@ -116,7 +116,7 @@ struct sock *inet6_steal_sock(struct net *net, struct sk_buff *skb, int doff, if (!sk) return NULL; - if (!prefetched) + if (!prefetched || !sk_fullsock(sk)) return sk; if (sk->sk_protocol == IPPROTO_TCP) { diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 84355722341437..3ecfeadbfa0694 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -462,7 +462,7 @@ struct sock *inet_steal_sock(struct net *net, struct sk_buff *skb, int doff, if (!sk) return NULL; - if (!prefetched) + if (!prefetched || !sk_fullsock(sk)) return sk; if (sk->sk_protocol == IPPROTO_TCP) { |