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author | Lorenz Bauer <lmb@isovalent.com> | 2023-08-15 10:53:41 +0200 |
---|---|---|
committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-08-15 22:57:51 +0200 |
commit | 8897562f67b3e61ad736cd5c9f307447d33280e4 (patch) | |
tree | d407c79392c986d17b4b16d9df68bcc4edbe31f1 /include/net/inet6_hashtables.h | |
parent | Merge branch 'Update and document struct_ops' (diff) | |
download | linux-8897562f67b3e61ad736cd5c9f307447d33280e4.tar.xz linux-8897562f67b3e61ad736cd5c9f307447d33280e4.zip |
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>
Diffstat (limited to 'include/net/inet6_hashtables.h')
-rw-r--r-- | include/net/inet6_hashtables.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h index 284b5ce7205d..533a7337865a 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) { |