[PATCH 5.3 122/135] net/tls: take into account that bpf_exec_tx_verdict() may free the record

Greg Kroah-Hartman
2019-12-03T23:09:15Z

From: Jakub Kicinski <jakub.kicinski@netronome.com>

[ Upstream commit c329ef9684de9517d82af5b4758c9e1b64a8a11a ]

bpf_exec_tx_verdict() may free the record if tls_push_record()
fails, or if the entire record got consumed by BPF. Re-check
ctx->open_rec before touching the data.

Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tls/tls_sw.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -979,7 +979,7 @@ alloc_encrypted:
num_async++;
else if (ret == -ENOMEM)
goto wait_for_memory;
- else if (ret == -ENOSPC)
+ else if (ctx->open_rec && ret == -ENOSPC)
goto rollback_iter;
else if (ret != -EAGAIN)
goto send_end;
@@ -1048,11 +1048,12 @@ wait_for_memory:
ret = sk_stream_wait_memory(sk, &timeo);
if (ret) {
trim_sgl:
- tls_trim_both_msgs(sk, orig_size);
+ if (ctx->open_rec)
+ tls_trim_both_msgs(sk, orig_size);
goto send_end;
}

- if (msg_en->sg.size < required_size)
+ if (ctx->open_rec && msg_en->sg.size < required_size)
goto alloc_encrypted;
}

@@ -1185,11 +1186,13 @@ wait_for_sndbuf:
wait_for_memory:
ret = sk_stream_wait_memory(sk, &timeo);
if (ret) {
- tls_trim_both_msgs(sk, msg_pl->sg.size);
+ if (ctx->open_rec)
+ tls_trim_both_msgs(sk, msg_pl->sg.size);
goto sendpage_end;
}

- goto alloc_payload;
+ if (ctx->open_rec)
+ goto alloc_payload;
}

if (num_async) {