4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Lutomirski <luto@xxxxxxxxxx>
commit b5069782453459f6ec1fdeb495d9901a4545fcb5 upstream.
POPF would trap if VIP was set regardless of whether IF was set. Fix it.
Suggested-by: Stas Sergeev <stsp@xxxxxxx>
Reported-by: Bart Oldeman <bartoldeman@xxxxxxxxx>
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5ed92a8ab71f ("x86/vm86: Use the normal pt_regs area for vm86")
Link: http://lkml.kernel.org/r/ce95f40556e7b2178b6bc06ee9557827ff94bd28.1521003603.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -715,7 +715,8 @@ 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;
}