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 <keesc...@chromium.org>
Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
---
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)