tree 0732f155cbe340909b755cc4b134fd86212f5dd3
parent 2c2b2f64de72b597413738524ebb8cafa33857a3
author Darrick J. Wong <djwong@kernel.org> 1657591513 -0700
committer Darrick J. Wong <djwong@kernel.org> 1657674350 -0700

mkfs: terminate getsubopt arrays properly

Having not drank any (or maybe too much) coffee this morning, I typed:

$ mkfs.xfs -d agcount=3 -d nrext64=0
Segmentation fault

I traced this down to getsubopt walking off the end of the dopts.subopts
array.  The manpage says you're supposed to terminate the suboptions
string array with a NULL entry, but the structure definition uses
MAX_SUBOPTS/D_MAX_OPTS directly, which means there is no terminator.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>