When seeing short packets, tcpdump prints out a warning like this:

09:39:12.829833 < truncated-ip - 46 bytes missing!192.168.42.112 >
thinktwice: i
cmp: echo request
                         4500 005c 8719 0000 ff01 5ec3 c0a8 2a70
                         c0a8 2a03 0800 cee9 3412 0500 1402 0000
                         0000 0000 0800 0000 0c00 0000 1000

But as can be seen, it's printing the length of the packet in the
warning, not the number of bytes missing (60-46 = 14).

Jesper