diff options
Diffstat (limited to 'main/xen/xsa192.patch')
| -rw-r--r-- | main/xen/xsa192.patch | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/main/xen/xsa192.patch b/main/xen/xsa192.patch new file mode 100644 index 00000000000..b573a132c9f --- /dev/null +++ b/main/xen/xsa192.patch @@ -0,0 +1,64 @@ +From: Jan Beulich <jbeulich@suse.com> +Subject: x86/HVM: don't load LDTR with VM86 mode attrs during task switch + +Just like TR, LDTR is purely a protected mode facility and hence needs +to be loaded accordingly. Also move its loading to where it +architecurally belongs. + +This is XSA-192. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> +Tested-by: Andrew Cooper <andrew.cooper3@citrix.com> + +--- a/xen/arch/x86/hvm/hvm.c ++++ b/xen/arch/x86/hvm/hvm.c +@@ -2728,17 +2728,16 @@ static void hvm_unmap_entry(void *p) + } + + static int hvm_load_segment_selector( +- enum x86_segment seg, uint16_t sel) ++ enum x86_segment seg, uint16_t sel, unsigned int eflags) + { + struct segment_register desctab, cs, segr; + struct desc_struct *pdesc, desc; + u8 dpl, rpl, cpl; + bool_t writable; + int fault_type = TRAP_invalid_tss; +- struct cpu_user_regs *regs = guest_cpu_user_regs(); + struct vcpu *v = current; + +- if ( regs->eflags & X86_EFLAGS_VM ) ++ if ( eflags & X86_EFLAGS_VM ) + { + segr.sel = sel; + segr.base = (uint32_t)sel << 4; +@@ -2986,6 +2985,8 @@ void hvm_task_switch( + if ( rc != HVMCOPY_okay ) + goto out; + ++ if ( hvm_load_segment_selector(x86_seg_ldtr, tss.ldt, 0) ) ++ goto out; + + if ( hvm_set_cr3(tss.cr3, 1) ) + goto out; +@@ -3008,13 +3009,12 @@ void hvm_task_switch( + } + + exn_raised = 0; +- if ( hvm_load_segment_selector(x86_seg_ldtr, tss.ldt) || +- hvm_load_segment_selector(x86_seg_es, tss.es) || +- hvm_load_segment_selector(x86_seg_cs, tss.cs) || +- hvm_load_segment_selector(x86_seg_ss, tss.ss) || +- hvm_load_segment_selector(x86_seg_ds, tss.ds) || +- hvm_load_segment_selector(x86_seg_fs, tss.fs) || +- hvm_load_segment_selector(x86_seg_gs, tss.gs) ) ++ if ( hvm_load_segment_selector(x86_seg_es, tss.es, tss.eflags) || ++ hvm_load_segment_selector(x86_seg_cs, tss.cs, tss.eflags) || ++ hvm_load_segment_selector(x86_seg_ss, tss.ss, tss.eflags) || ++ hvm_load_segment_selector(x86_seg_ds, tss.ds, tss.eflags) || ++ hvm_load_segment_selector(x86_seg_fs, tss.fs, tss.eflags) || ++ hvm_load_segment_selector(x86_seg_gs, tss.gs, tss.eflags) ) + exn_raised = 1; + + rc = hvm_copy_to_guest_virt( |