x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytes

Since insn.prefixes.nbytes can be bigger than the size of
insn.prefixes.bytes[] when a prefix is repeated, the proper check must
be

  insn.prefixes.bytes[i] != 0 and i < 4

instead of using insn.prefixes.nbytes. Use the new
for_each_insn_prefix() macro which does it correctly.

Debugged by Kees Cook <[email protected]>.

 [ bp: Massage commit message. ]

Fixes: 32d0b95300db ("x86/insn-eval: Add utility functions to get segment selector")
Reported-by: [email protected]
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/160697104969.3146288.16329307586428270032.stgit@devnote2

0 files changed, 0 insertions, 0 deletions