[xen stable-4.12] tools/libxl: Fix memory leak in libxl_cpuid_set()

[patchbot@xxxxxxx]

commit 06760c2bf322cef4622b56bafee74fe93ae01630
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Jun 12 18:32:27 2020 +0100
Commit:     Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
CommitDate: Mon Jun 15 15:46:17 2020 +0100

    tools/libxl: Fix memory leak in libxl_cpuid_set()
    
    xc_cpuid_set() returns allocated memory via cpuid_res, which libxl needs to
    free() seeing as it discards the results.
    
    This is logically a backport of c/s b91825f628 "tools/libxc: Drop
    config_transformed parameter from xc_cpuid_set()" but rewritten as one 
caller
    of xc_cpuid_set() does use returned values.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    (cherry picked from commit c54de7d9df7718ea53bf21e1ff5bbd339602a704)
---
 tools/libxl/libxl_cpuid.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/libxl/libxl_cpuid.c b/tools/libxl/libxl_cpuid.c
index 88b5760c85..07995c81d1 100644
--- a/tools/libxl/libxl_cpuid.c
+++ b/tools/libxl/libxl_cpuid.c
@@ -404,12 +404,17 @@ void libxl_cpuid_apply_policy(libxl_ctx *ctx, uint32_t 
domid)
 void libxl_cpuid_set(libxl_ctx *ctx, uint32_t domid,
                      libxl_cpuid_policy_list cpuid)
 {
-    int i;
+    int i, j;
     char *cpuid_res[4];
 
     for (i = 0; cpuid[i].input[0] != XEN_CPUID_INPUT_UNUSED; i++)
+    {
         xc_cpuid_set(ctx->xch, domid, cpuid[i].input,
                      (const char**)(cpuid[i].policy), cpuid_res);
+
+        for (j = 0; j < ARRAY_SIZE(cpuid_res); ++j)
+            free(cpuid_res[j]);
+    }
 }
 
 static const char *input_names[2] = { "leaf", "subleaf" };
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.12