]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
KVM: x86: Fix far-jump to non-canonical check
authorNadav Amit <namit@cs.technion.ac.il>
Mon, 27 Oct 2014 22:03:43 +0000 (00:03 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Sun, 2 Nov 2014 06:54:55 +0000 (07:54 +0100)
commit7e46dddd6f6cd5dbf3c7bd04a7e75d19475ac9f2
tree5c374dad5036d05134f833c10073bc89a0f85657
parentfd56e1546a5f734290cbedd2b81c518850736511
KVM: x86: Fix far-jump to non-canonical check

Commit d1442d85cc30 ("KVM: x86: Handle errors when RIP is set during far
jumps") introduced a bug that caused the fix to be incomplete.  Due to
incorrect evaluation, far jump to segment with L bit cleared (i.e., 32-bit
segment) and RIP with any of the high bits set (i.e, RIP[63:32] != 0) set may
not trigger #GP.  As we know, this imposes a security problem.

In addition, the condition for two warnings was incorrect.

Fixes: d1442d85cc30ea75f7d399474ca738e0bc96f715
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
[Add #ifdef CONFIG_X86_64 to avoid complaints of undefined behavior. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/emulate.c