[Xen-changelog] [xen stable-4.5] x86/AMD-ucode: correct multiple container handling

[patchbot@xxxxxxx]

commit 4d9ba7b2188083a09d1b1a1bda7054cc3eb77f67
Author:     Jan Beulich <JBeulich@xxxxxxxx>
AuthorDate: Mon Dec 15 09:16:09 2014 +0000
Commit:     Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CommitDate: Mon Jan 5 10:20:31 2015 -0500

    x86/AMD-ucode: correct multiple container handling
    
    Avoid emitting an error message referring to an incorrect or corrupt
    container file just because no entry was found for the running CPU.
    
    Additionally switch the order of data validation and consumption in
    cpu_request_microcode()'s first loop, and also check the types of
    skipped blocks in container_fast_forward().
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
    Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
    Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 xen/arch/x86/microcode_amd.c |   18 ++++++++++++++----
 1 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index b68cf93..f79b397 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -331,12 +331,17 @@ static int container_fast_forward(const void *data, 
size_t size_left, size_t *of
              header[1] == UCODE_EQUIV_CPU_TABLE_TYPE )
             break;
 
+        if ( header[0] != UCODE_UCODE_TYPE )
+            return -EINVAL;
         size = header[1] + SECTION_HDR_SIZE;
         if ( size < PATCH_HDR_SIZE || size_left < size )
             return -EINVAL;
 
         size_left -= size;
         *offset += size;
+
+        if ( !size_left )
+            return -ENODATA;
     }
 
     return 0;
@@ -386,10 +391,6 @@ static int cpu_request_microcode(int cpu, const void *buf, 
size_t bufsize)
             break;
         }
 
-        if ( find_equiv_cpu_id(mc_amd->equiv_cpu_table, current_cpu_id,
-                               &equiv_cpu_id) )
-                break;
-
         /*
          * Could happen as we advance 'offset' early
          * in install_equiv_cpu_table
@@ -401,7 +402,16 @@ static int cpu_request_microcode(int cpu, const void *buf, 
size_t bufsize)
             break;
         }
 
+        if ( find_equiv_cpu_id(mc_amd->equiv_cpu_table, current_cpu_id,
+                               &equiv_cpu_id) )
+            break;
+
         error = container_fast_forward(buf, bufsize - offset, &offset);
+        if ( error == -ENODATA )
+        {
+            ASSERT(offset == bufsize);
+            break;
+        }
         if ( error )
         {
             printk(KERN_ERR "microcode: CPU%d incorrect or corrupt container 
file\n"
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.5

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