4.16-stable patches

added patches:
	kvm-x86-use-correct-privilege-level-for-sgdt-sidt-fxsave-fxrstor-access.patch

diff --git a/queue-4.16/kvm-x86-use-correct-privilege-level-for-sgdt-sidt-fxsave-fxrstor-access.patch b/queue-4.16/kvm-x86-use-correct-privilege-level-for-sgdt-sidt-fxsave-fxrstor-access.patch
new file mode 100644 (file)
index 0000000..6a0638c
--- /dev/null
+++ b/queue-4.16/kvm-x86-use-correct-privilege-level-for-sgdt-sidt-fxsave-fxrstor-access.patch
@@ -0,0 +1,149 @@
+From 3c9fa24ca7c9c47605672916491f79e8ccacb9e6 Mon Sep 17 00:00:00 2001
+From: Paolo Bonzini <pbonzini@redhat.com>
+Date: Wed, 6 Jun 2018 17:38:09 +0200
+Subject: kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
+
+From: Paolo Bonzini <pbonzini@redhat.com>
+
+commit 3c9fa24ca7c9c47605672916491f79e8ccacb9e6 upstream.
+
+The functions that were used in the emulation of fxrstor, fxsave, sgdt and
+sidt were originally meant for task switching, and as such they did not
+check privilege levels.  This is very bad when the same functions are used
+in the emulation of unprivileged instructions.  This is CVE-2018-10853.
+
+The obvious fix is to add a new argument to ops->read_std and ops->write_std,
+which decides whether the access is a "system" access or should use the
+processor's CPL.
+
+Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/include/asm/kvm_emulate.h |    6 ++++--
+ arch/x86/kvm/emulate.c             |   12 ++++++------
+ arch/x86/kvm/x86.c                 |   18 ++++++++++++++----
+ 3 files changed, 24 insertions(+), 12 deletions(-)
+
+--- a/arch/x86/include/asm/kvm_emulate.h
++++ b/arch/x86/include/asm/kvm_emulate.h
+@@ -107,11 +107,12 @@ struct x86_emulate_ops {
+        *  @addr:  [IN ] Linear address from which to read.
+        *  @val:   [OUT] Value read from memory, zero-extended to 'u_long'.
+        *  @bytes: [IN ] Number of bytes to read from memory.
++       *  @system:[IN ] Whether the access is forced to be at CPL0.
+        */
+       int (*read_std)(struct x86_emulate_ctxt *ctxt,
+                       unsigned long addr, void *val,
+                       unsigned int bytes,
+-                      struct x86_exception *fault);
++                      struct x86_exception *fault, bool system);
+ 
+       /*
+        * read_phys: Read bytes of standard (non-emulated/special) memory.
+@@ -129,10 +130,11 @@ struct x86_emulate_ops {
+        *  @addr:  [IN ] Linear address to which to write.
+        *  @val:   [OUT] Value write to memory, zero-extended to 'u_long'.
+        *  @bytes: [IN ] Number of bytes to write to memory.
++       *  @system:[IN ] Whether the access is forced to be at CPL0.
+        */
+       int (*write_std)(struct x86_emulate_ctxt *ctxt,
+                        unsigned long addr, void *val, unsigned int bytes,
+-                       struct x86_exception *fault);
++                       struct x86_exception *fault, bool system);
+       /*
+        * fetch: Read bytes of standard (non-emulated/special) memory.
+        *        Used for instruction fetch.
+--- a/arch/x86/kvm/emulate.c
++++ b/arch/x86/kvm/emulate.c
+@@ -814,14 +814,14 @@ static inline int jmp_rel(struct x86_emu
+ static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear,
+                             void *data, unsigned size)
+ {
+-      return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
++      return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, true);
+ }
+ 
+ static int linear_write_system(struct x86_emulate_ctxt *ctxt,
+                              ulong linear, void *data,
+                              unsigned int size)
+ {
+-      return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception);
++      return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, true);
+ }
+ 
+ static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
+@@ -835,7 +835,7 @@ static int segmented_read_std(struct x86
+       rc = linearize(ctxt, addr, size, false, &linear);
+       if (rc != X86EMUL_CONTINUE)
+               return rc;
+-      return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
++      return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, false);
+ }
+ 
+ static int segmented_write_std(struct x86_emulate_ctxt *ctxt,
+@@ -849,7 +849,7 @@ static int segmented_write_std(struct x8
+       rc = linearize(ctxt, addr, size, true, &linear);
+       if (rc != X86EMUL_CONTINUE)
+               return rc;
+-      return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception);
++      return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, false);
+ }
+ 
+ /*
+@@ -2916,12 +2916,12 @@ static bool emulator_io_port_access_allo
+ #ifdef CONFIG_X86_64
+       base |= ((u64)base3) << 32;
+ #endif
+-      r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
++      r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL, true);
+       if (r != X86EMUL_CONTINUE)
+               return false;
+       if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
+               return false;
+-      r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
++      r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL, true);
+       if (r != X86EMUL_CONTINUE)
+               return false;
+       if ((perm >> bit_idx) & mask)
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -4716,10 +4716,15 @@ EXPORT_SYMBOL_GPL(kvm_read_guest_virt);
+ 
+ static int emulator_read_std(struct x86_emulate_ctxt *ctxt,
+                            gva_t addr, void *val, unsigned int bytes,
+-                           struct x86_exception *exception)
++                           struct x86_exception *exception, bool system)
+ {
+       struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
+-      return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, 0, exception);
++      u32 access = 0;
++
++      if (!system && kvm_x86_ops->get_cpl(vcpu) == 3)
++              access |= PFERR_USER_MASK;
++
++      return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access, exception);
+ }
+ 
+ static int kvm_read_guest_phys_system(struct x86_emulate_ctxt *ctxt,
+@@ -4763,12 +4768,17 @@ out:
+ }
+ 
+ static int emulator_write_std(struct x86_emulate_ctxt *ctxt, gva_t addr, void *val,
+-                            unsigned int bytes, struct x86_exception *exception)
++                            unsigned int bytes, struct x86_exception *exception,
++                            bool system)
+ {
+       struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
++      u32 access = PFERR_WRITE_MASK;
++
++      if (!system && kvm_x86_ops->get_cpl(vcpu) == 3)
++              access |= PFERR_USER_MASK;
+ 
+       return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
+-                                         PFERR_WRITE_MASK, exception);
++                                         access, exception);
+ }
+ 
+ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,

diff --git a/queue-4.16/series b/queue-4.16/series
index 10aceb789d03bc546893e0651fab42d8a62266d2..2a17f8cdc631254346150eba49cb9e1a509082a6 100644 (file)
--- a/queue-4.16/series
+++ b/queue-4.16/series
@@ -28,3 +28,4 @@ serial-samsung-fix-maxburst-parameter-for-dma-transactions.patch
 serial-8250-omap-fix-idling-of-clocks-for-unused-uarts.patch
 vmw_balloon-fixing-double-free-when-batching-mode-is-off.patch
 tty-pl011-avoid-spuriously-stuck-off-interrupts.patch
+kvm-x86-use-correct-privilege-level-for-sgdt-sidt-fxsave-fxrstor-access.patch