JargonFile/entries/buffer overflow.txt

buffer overflow

n. What happens when you try to stuff more data into a buffer (holding area)
than it can handle. This problem is commonly exploited by crackers to get
arbitrary commands executed by a program running with root permissions. This
may be due to a mismatch in the processing rates of the producing and
consuming processes (see overrun and firehose syndrome ), or because the
buffer is simply too small to hold all the data that must accumulate before
a piece of it can be processed. For example, in a text-processing tool that
crunch es a line at a time, a short line buffer can result in lossage as
input from a long line overflows the buffer and trashes data beyond it. Good
defensive programming would check for overflow on each character and stop
accepting data when the buffer is full up. The term is used of and by humans
in a metaphorical sense. What time did I agree to meet you? My buffer must
have overflowed. Or If I answer that phone my buffer is going to overflow.
See also spam , overrun screw.