4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski <luto@kernel.org>

commit b5069782453459f6ec1fdeb495d9901a4545fcb5 upstream.

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

Suggested-by: Stas Sergeev <redacted>
Reported-by: Bart Oldeman <redacted>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <redacted>
Cc: Denys Vlasenko <redacted>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <redacted>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <redacted>
Cc: stable@vger.kernel.org
Fixes: 5ed92a8ab71f ("x86/vm86: Use the normal pt_regs area for vm86")
Link: http://lkml.kernel.org/r/ce95f40556e7b2178b6bc06ee9557827ff94bd28.1521003603.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/vm86_32.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c

@@ -719,7 +719,8 @@ void handle_vm86_fault(struct kernel_vm8
 	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;
 	}