In the zerocopy sendmsg() path, there are error checks to revert
the zerocopy if we get any error code. syzkaller has discovered
that tls_push_record can return -ECONNRESET, which is fatal, and
happens after the point at which it is safe to revert the iter,
as we've already passed the memory to do_tcp_sendpages.
Previously this code could return -ENOMEM and we would want to
revert the iter, but AFAIK this no longer returns ENOMEM after
a447da7d004 ("tls: fix waitall behavior in tls_sw_recvmsg"),
so we fail for all error codes.
Reported-by: syzbot+c226690f7b3126c5e...@syzkaller.appspotmail.com
Reported-by: syzbot+709f2810a6a05f11d...@syzkaller.appspotmail.com
Signed-off-by: Dave Watson <davejwat...@fb.com>
Fixes: 3c4d7559159b ("tls: kernel TLS support")
---
net/tls/tls_sw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 7818011fd250..4618f1c31137 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -440,7 +440,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg,
size_t size)
ret = tls_push_record(sk, msg->msg_flags, record_type);
if (!ret)
continue;
- if (ret == -EAGAIN)
+ if (ret < 0)
goto send_end;
copied -= try_to_copy;
--
2.17.1
