00000000 <queue_work>:
   0:   55                      push   %ebp
   1:   89 d1                   mov    %edx,%ecx
   3:   89 e5                   mov    %esp,%ebp
...
...

  6c:   c3                      ret
  6d:   0f 0b                   ud2a
  6f:   4d                      dec    %ebp
  70:   00 00                   add    %al,(%eax)
  72:   00 00                   add    %al,(%eax)
  74:   00 eb                   add    %ch,%bl
  76:   b2 89                   mov    $0x89,%dl
  78:   f6 8d bc 27 00 00       (bad)  0x27bc(%ebp)
        ...

What it's the meaning of bad (instruction)?

gcc -v

Reading specs from /usr/lib/gcc-lib/i386-linux/3.3.1/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info
--with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-debug --enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc
i386-linux
Thread model: posix
gcc version 3.3.1 20030626 (Debian prerelease)