Date: Wed, 21 Jul 2021 04:55:14 +0000 From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 257302] net/syncthing: Panic in in6_getmulti at /usr/src/sys/netinet6/in6_mcast.c:451 Message-ID: <bug-257302-7501-QsqaNfvNto@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-257302-7501@https.bugs.freebsd.org/bugzilla/> References: <bug-257302-7501@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=257302 --- Comment #4 from Alex Vasylenko <lxv@omut.org> --- The following golang program reproduces the issue, no root required; it was a mcast join on ipfw0 after all, but has to be an IPv6 join. $ cat mcast6_join.go package main import ( "fmt" "net" "golang.org/x/net/ipv6" ) func main() { addr := "[ff12::8384]:21027" gaddr, err := net.ResolveUDPAddr("udp6", addr) if err != nil { fmt.Println(err) return } conn, err := net.ListenPacket("udp6", addr) if err != nil { fmt.Println(err) return } defer conn.Close() intf, err := net.InterfaceByName("ipfw0") if err != nil { fmt.Println(err) return } pconn := ipv6.NewPacketConn(conn) result := pconn.JoinGroup(intf, &net.UDPAddr{IP: gaddr.IP}) if result != nil { fmt.Println("IPv6 join", intf.Name, "failed:", result) } else { fmt.Println("IPv6 join", intf.Name, "success") } } net/syncthing has something like the above in https://github.com/syncthing/syncthing/blob/main/lib/beacon/multicast.go#L101 (except they perform join on all interfaces in a loop ignoring multicast flag, but that's beside the point) A relevant part from vmcore that I failed to include in the original report was this: (kgdb) f 14 #14 0xffffffff80c584d6 in sosetopt (so=0xfffff80012986a38, sopt=0xfffffe005c3cfb98) at /usr/src/sys/kern/uipc_socket.c:2761 2761 error = (*so->so_proto->pr_ctloutput)(so, sopt); (kgdb) set print pretty (kgdb) p *sopt $1 = { sopt_dir = SOPT_SET, sopt_level = 41, sopt_name = 80, sopt_val = 0xc000320900, sopt_valsize = 136, sopt_td = 0xfffff800126f9000 } optname 80 is MCAST_JOIN_GROUP -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug.help
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