octave, 70 bytes

Result

AC

Duration

1060ms

Code [DL]

m=scanf("%d%d");s=repmat('*',h=m(1),w=m(2));s(2:h-1,2:w-1)=' ';disp(s)

stdin

31
93

stdout

*********************************************************************************************
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
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*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*                                                                                           *
*********************************************************************************************

stderr

octave: X11 DISPLAY environment variable not set
octave: disabling GUI features