r0 = epoll_create1(0x0)
r1 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$inet6(r1, &(0x7f0000000000)={0xa, 0x0, 0x0, @ipv4={'\x00', '\xff\xff', @empty}}, 0x1c)
setsockopt$inet6_IPV6_ADDRFORM(r1, 0x29, 0x1, &(0x7f00000000c0), 0x4)
r2 = socket$inet6_udp(0xa, 0x2, 0x0)
epoll_ctl$EPOLL_CTL_ADD(r0, 0x1, r1, &(0x7f0000000040))
dup2(r1, r2)
r3 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000080)='mounts\x00')
sendfile(r2, r3, 0x0, 0xffd0)