From: Eric Dumazet <edumazet@google.com>
To: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, bpf <bpf@vger.kernel.org>,
Lawrence Brakmo <brakmo@fb.com>
Subject: [PATCH bpf] bpf: properly check TCP_CONGESTION optlen
Date: Sat, 23 Feb 2019 11:07:09 -0800 [thread overview]
Message-ID: <20190223190709.61558-1-edumazet@google.com> (raw)
If caller of bpf_setsockopt() is silly passing a negative optlen
bad things happen.
Fixes: 91b5b21c7c16 ("bpf: Add support for changing congestion control")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
---
net/core/filter.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index f7d0004fc16096eb42ece3a6acf645540ee2326b..6a5d89464168f2f35f43986c1dbc0446c9390a3c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4194,8 +4194,9 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
char name[TCP_CA_NAME_MAX];
bool reinit = bpf_sock->op > BPF_SOCK_OPS_NEEDS_ECN;
- strncpy(name, optval, min_t(long, optlen,
- TCP_CA_NAME_MAX-1));
+ if (optlen < 0)
+ return -EINVAL;
+ strncpy(name, optval, min(optlen, TCP_CA_NAME_MAX - 1));
name[TCP_CA_NAME_MAX-1] = 0;
ret = tcp_set_congestion_control(sk, name, false,
reinit);
--
2.21.0.rc0.258.g878e2cd30e-goog
next reply other threads:[~2019-02-23 19:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-23 19:07 Eric Dumazet [this message]
2019-02-23 20:38 ` [PATCH bpf] bpf: properly check TCP_CONGESTION optlen Alexei Starovoitov
2019-02-23 20:48 ` Eric Dumazet
2019-02-23 23:11 ` Alexei Starovoitov
2019-02-25 11:07 ` Daniel Borkmann
2019-02-25 15:43 ` Eric Dumazet
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