diff options
authorDaniel Borkmann <daniel@iogearbox.net>2018-08-08 19:23:13 +0200
committerAlexei Starovoitov <ast@kernel.org>2018-08-08 12:06:17 -0700
commit5121700b346b6160ccc9411194e3f1f417c340d1 (patch)
parent74682128c6e456b529b25b95ba807484ce58a753 (diff)
bpf, sockmap: fix bpf_tcp_sendmsg sock error handling
While working on bpf_tcp_sendmsg() code, I noticed that when a sk->sk_err is set we error out with err = sk->sk_err. However this is problematic since sk->sk_err is a positive error value and therefore we will neither go into sk_stream_error() nor will we report an error back to user space. I had this case with EPIPE and user space was thinking sendmsg() succeeded since EPIPE is a positive value, thinking we submitted 32 bytes. Fix it by negating the sk->sk_err value. Fixes: 4f738adba30a ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 98fb7938beea..f7360c4d7250 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -1053,7 +1053,7 @@ static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
int copy;
if (sk->sk_err) {
- err = sk->sk_err;
+ err = -sk->sk_err;
goto out_err;