r0 = syz_open_dev$tty20(0xc, 0x4, 0x0)
r1 = openat$procfs(0xffffffffffffff9c, &(0x7f0000000100)='/proc/vmstat\x00', 0x0, 0x0)
sendfile(r0, r1, &(0x7f0000000180)=0x80, 0x5b)