net: tls, update curr on splice as well

jira VULN-6841
cve CVE-2024-0646
commit-author John Fastabend <john.fastabend@gmail.com>
commit c5a5950
upstream-diff used linux-stable LT-5.15 sha ba5efd8

commit c5a5950 upstream.

The curr pointer must also be updated on the splice similar to how
we do this for other copy types.

Fixes: d829e9c ("tls: convert to generic sk_msg interface")
	Signed-off-by: John Fastabend <john.fastabend@gmail.com>
	Reported-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20231206232706.374377-2-john.fastabend@gmail.com
	Signed-off-by: Jakub Kicinski <kuba@kernel.org>
	Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ba5efd8)
	Signed-off-by: Marcin Wcisło <marcin.wcislo@conclusive.pl>

Author: pvts-mat

net/tls/tls_sw.c

@@ -1213,6 +1213,8 @@ static int tls_sw_do_sendpage(struct sock *sk, struct page *page,
 		}
 
 		sk_msg_page_add(msg_pl, page, copy, offset);
+		msg_pl->sg.copybreak = 0;
+		msg_pl->sg.curr = msg_pl->sg.end;
 		sk_mem_charge(sk, copy);
 
 		offset += copy;