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[Xen-changelog] [xen staging] xen/arm: domain: Zero the per-vCPU cpu_info

commit 213aa75aece5efefe76448c86b50b957901c7baf
Author:     Julien Grall <julien.grall@xxxxxxx>
AuthorDate: Tue Jun 12 12:36:31 2018 +0100
Commit:     Julien Grall <julien.grall@xxxxxxx>
CommitDate: Fri Jun 22 02:55:12 2018 +0100

    xen/arm: domain: Zero the per-vCPU cpu_info
    A stack is allocated per vCPU to be used by Xen. The allocation is done
    with alloc_xenheap_pages that does not zero the memory returned. However
    the top of the stack is containing information that will be used to
    store the initial state of the vCPU (see struct cpu_info). Some of the
    fields may not be initialized and will lead to use/leak bits of previous
    memory in some cases on the first run of vCPU (AFAICT this only happen on
    vCPU0 for Dom0).
    This is part of XSA-263.
    Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
 xen/arch/arm/domain.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index ec0f042bf7..5a2a9a6b83 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -550,6 +550,7 @@ int vcpu_initialise(struct vcpu *v)
     v->arch.cpu_info = (struct cpu_info *)(v->arch.stack
                                            + STACK_SIZE
                                            - sizeof(struct cpu_info));
+    memset(v->arch.cpu_info, 0, sizeof(*v->arch.cpu_info));
     memset(&v->arch.saved_context, 0, sizeof(v->arch.saved_context));
     v->arch.saved_context.sp = (register_t)v->arch.cpu_info;
generated by git-patchbot for /home/xen/git/xen.git#staging

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