libuuid: Make sure fd's 0, 1, and 2 are valid before exec'ing uuidd

When closing all of the file descriptors before starting uuidd, make
sure file descriptors 0, 1, and 2 are reserved by opening /dev/null.
This prevents strange bugs caused by assumptions regarding file
descriptors <= 2 as being special.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
1 file changed