xen/55a77e4f-dmar-device-scope-mem-leak-fix.patch

# Commit a8bc99b981c5ad773bd646f5986e616d26fb94d7
# Date 2015-07-16 11:50:07 +0200
# Author Elena Ufimtseva <elena.ufimtseva@oracle.com>
# Committer Jan Beulich <jbeulich@suse.com>
dmar: device scope mem leak fix

Release memory allocated for scope.devices dmar units on various
failure paths and when disabling dmar. Set device count after
sucessfull memory allocation, not before, in device scope parsing function.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Yang Zhang <yang.z.zhang@intel.com>

# Commit 132231d10343608faf5892785a08acc500326d04
# Date 2015-07-16 15:23:37 +0200
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Jan Beulich <jbeulich@suse.com>
dmar: fix double free in error paths following c/s a8bc99b

Several error paths would end up freeing scope->devices twice.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -80,6 +80,16 @@ static int __init acpi_register_rmrr_uni
     return 0;
 }
 
+static void scope_devices_free(struct dmar_scope *scope)
+{
+    if ( !scope )
+        return;
+
+    scope->devices_cnt = 0;
+    xfree(scope->devices);
+    scope->devices = NULL;
+}
+
 static void __init disable_all_dmar_units(void)
 {
     struct acpi_drhd_unit *drhd, *_drhd;
@@ -89,16 +99,19 @@ static void __init disable_all_dmar_unit
     list_for_each_entry_safe ( drhd, _drhd, &acpi_drhd_units, list )
     {
         list_del(&drhd->list);
+        scope_devices_free(&drhd->scope);
         xfree(drhd);
     }
     list_for_each_entry_safe ( rmrr, _rmrr, &acpi_rmrr_units, list )
     {
         list_del(&rmrr->list);
+        scope_devices_free(&rmrr->scope);
         xfree(rmrr);
     }
     list_for_each_entry_safe ( atsr, _atsr, &acpi_atsr_units, list )
     {
         list_del(&atsr->list);
+        scope_devices_free(&atsr->scope);
         xfree(atsr);
     }
 }
@@ -317,13 +330,13 @@ static int __init acpi_parse_dev_scope(
     if ( (cnt = scope_device_count(start, end)) < 0 )
         return cnt;
 
-    scope->devices_cnt = cnt;
     if ( cnt > 0 )
     {
         scope->devices = xzalloc_array(u16, cnt);
         if ( !scope->devices )
             return -ENOMEM;
     }
+    scope->devices_cnt = cnt;
 
     while ( start < end )
     {
@@ -426,7 +439,7 @@ static int __init acpi_parse_dev_scope(
 
  out:
     if ( ret )
-        xfree(scope->devices);
+        scope_devices_free(scope);
 
     return ret;
 }
@@ -541,6 +554,7 @@ acpi_parse_one_drhd(struct acpi_dmar_hea
                     "  Workaround BIOS bug: ignore the DRHD due to all "
                     "devices under its scope are not PCI discoverable!\n");
 
+                scope_devices_free(&dmaru->scope);
                 iommu_free(dmaru);
                 xfree(dmaru);
             }
@@ -561,9 +575,11 @@ acpi_parse_one_drhd(struct acpi_dmar_hea
 out:
     if ( ret )
     {
+        scope_devices_free(&dmaru->scope);
         iommu_free(dmaru);
         xfree(dmaru);
     }
+
     return ret;
 }
 
@@ -657,6 +673,7 @@ acpi_parse_one_rmrr(struct acpi_dmar_hea
                 "  Ignore the RMRR (%"PRIx64", %"PRIx64") due to "
                 "devices under its scope are not PCI discoverable!\n",
                 rmrru->base_address, rmrru->end_address);
+            scope_devices_free(&rmrru->scope);
             xfree(rmrru);
         }
         else if ( base_addr > end_addr )
@@ -664,6 +681,7 @@ acpi_parse_one_rmrr(struct acpi_dmar_hea
             dprintk(XENLOG_WARNING VTDPREFIX,
                 "  The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
                 rmrru->base_address, rmrru->end_address);
+            scope_devices_free(&rmrru->scope);
             xfree(rmrru);
             ret = -EFAULT;
         }
@@ -726,7 +744,10 @@ acpi_parse_one_atsr(struct acpi_dmar_hea
     }
 
     if ( ret )
+    {
+        scope_devices_free(&atsru->scope);
         xfree(atsru);
+    }
     else
         acpi_register_atsr_unit(atsru);
     return ret;