[PATCH 3/3] x86/vm86/32: Fix POPF emulation

From: Andy Lutomirski
Date: Wed Mar 14 2018 - 01:03:39 EST


POPF would trap if VIP was set regardless of whether IF was set. Fix it.

Reported-by: Bart Oldeman <bartoldeman@xxxxxxxxx>
Suggested-by: Stas Sergeev <stsp@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5ed92a8ab71f ("x86/vm86: Use the normal pt_regs area for vm86")
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kernel/vm86_32.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 5edb27f1a2c4..9d0b5af7db91 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -727,7 +727,8 @@ void handle_vm86_fault(struct kernel_vm86_regs *regs, long error_code)
return;

check_vip:
- if (VEFLAGS & X86_EFLAGS_VIP) {
+ if ((VEFLAGS & (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) ==
+ (X86_EFLAGS_VIP | X86_EFLAGS_VIF)) {
save_v86_state(regs, VM86_STI);
return;
}
--
2.14.3