Messages in this thread | | | Date | Mon, 6 Dec 2021 07:55:15 -0800 | From | Jakub Kicinski <> | Subject | Re: [PATCH mptcp] mptcp: remove tcp ulp setsockopt support |
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On Mon, 6 Dec 2021 07:53:26 -0800 Jakub Kicinski wrote: > On Sun, 5 Dec 2021 20:27:00 +0100 Florian Westphal wrote: > > TCP_ULP setsockopt cannot be used for mptcp because its already > > used internally to plumb subflow (tcp) sockets to the mptcp layer. > > > > syzbot managed to trigger a crash for mptcp connections that are > > in fallback mode: > > Fallback mode meaning ops are NULL? I'm slightly confused by this > report.
Ah, it's the socket not the ops.
> > KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] > > CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0 > > RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline] > > [..] > > __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline] > > tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160 > > do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391 > > mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638 > > > > Remove support for TCP_ULP setsockopt. > > > > Reported-by: syzbot+1fd9b69cde42967d1add@syzkaller.appspotmail.com > > Signed-off-by: Florian Westphal <fw@strlen.de>
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