On 12/2/20 2:51 AM, Masami Hiramatsu wrote:
Since the insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a same prefix is repeated, we have to check whether the insn.prefixes.bytes[i] != 0 and i < 4 instead of insn.prefixes.nbytes.Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: Kees Cook <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> --- arch/x86/boot/compressed/sev-es.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/sev-es.c b/arch/x86/boot/compressed/sev-es.c index 954cb2702e23..6a7a3027c9ac 100644 --- a/arch/x86/boot/compressed/sev-es.c +++ b/arch/x86/boot/compressed/sev-es.c @@ -36,7 +36,7 @@ static bool insn_has_rep_prefix(struct insn *insn)insn_get_prefixes(insn); - for (i = 0; i < insn->prefixes.nbytes; i++) {+ for (i = 0; insn->prefixes.bytes[i] && i < 4; i++) {
Wouldn't it be better to create a #define for the size rather than hard coding 4 in the various files? That would protect everything should the bytes array size ever change in the future.
Thanks, Tom
insn_byte_t p = insn->prefixes.bytes[i];if (p == 0xf2 || p == 0xf3)
