[xen stable-4.11] libxc/restore: Fix data auditing in handle_x86_pv_vcpu_blob()

[patchbot@xxxxxxx]

commit a58bba28da793da70b93b841289d99370800180c
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Thu Dec 19 20:32:20 2019 +0000
Commit:     Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
CommitDate: Tue May 5 15:47:21 2020 +0100

    libxc/restore: Fix data auditing in handle_x86_pv_vcpu_blob()
    
    The current logic only works by chance, in that XSAVE records also tend to 
be
    a multiple of 128.  Implement the missing logic for XSAVE.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
    (cherry picked from commit 2a62c22715bf81c5695ae0511f89a940c7c6a492)
    (cherry picked from commit 0e2bbcf8b4fe6f5fd23a341848f3785c213b26bb)
    (cherry picked from commit 288872ad3bb320bd9f31145d9bd4e53786fa3245)
---
 tools/libxc/xc_sr_restore_x86_pv.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/libxc/xc_sr_restore_x86_pv.c 
b/tools/libxc/xc_sr_restore_x86_pv.c
index 0f02751992..8c7adaeeda 100644
--- a/tools/libxc/xc_sr_restore_x86_pv.c
+++ b/tools/libxc/xc_sr_restore_x86_pv.c
@@ -825,6 +825,15 @@ static int handle_x86_pv_vcpu_blob(struct xc_sr_context 
*ctx,
         break;
 
     case REC_TYPE_X86_PV_VCPU_XSAVE:
+        if ( blobsz < 128 )
+        {
+            ERROR("%s record too short: min %zu, got %u",
+                  rec_name, sizeof(*vhdr) + 128, rec->length);
+            goto out;
+        }
+        break;
+
+    case REC_TYPE_X86_PV_VCPU_MSRS:
         if ( blobsz % sizeof(xen_domctl_vcpu_msr_t) != 0 )
         {
             ERROR("%s record payload size %zu expected to be a multiple of 
%zu",
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.11