migration: catch unknown flags in ram_load

if a saved vm has unknown flags in the memory data qemu
currently simply ignores this flag and continues which
yields in an unpredictable result.

This patch catches all unknown flags and aborts the
loading of the vm. Additionally error reports are thrown
if the migration aborts abnormally.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit db80facefa62dff42bb50c73b0f03eda5f732b49)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/arch_init.c b/arch_init.c
index 9aeb2b568c800d7cd447df47a60d8a6f4badcbc3..3ec70def569905aaf589aafdc4e47685845d0549 100644 (file)
--- a/arch_init.c
+++ b/arch_init.c
@@ -992,17 +992,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 {
     ram_addr_t addr;
     int flags, ret = 0;
-    int error;
     static uint64_t seq_iter;
 
     seq_iter++;
 
     if (version_id != 4) {
         ret = -EINVAL;
-        goto done;
     }
 
-    do {
+    while (!ret) {
         addr = qemu_get_be64(f);
 
         flags = addr & ~TARGET_PAGE_MASK;
@@ -1031,7 +1029,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                                     " in != " RAM_ADDR_FMT "\n", id, length,
                                     block->length);
                             ret =  -EINVAL;
-                            goto done;
                         }
                         break;
                     }
@@ -1041,21 +1038,22 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                     fprintf(stderr, "Unknown ramblock \"%s\", cannot "
                             "accept migration\n", id);
                     ret = -EINVAL;
-                    goto done;
+                }
+                if (ret) {
+                    break;
                 }
 
                 total_ram_bytes -= length;
             }
-        }
-
-        if (flags & RAM_SAVE_FLAG_COMPRESS) {
+        } else if (flags & RAM_SAVE_FLAG_COMPRESS) {
             void *host;
             uint8_t ch;
 
             host = host_from_stream_offset(f, addr, flags);
             if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
                 ret = -EINVAL;
-                goto done;
+                break;
             }
 
             ch = qemu_get_byte(f);
@@ -1065,33 +1063,39 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 
             host = host_from_stream_offset(f, addr, flags);
             if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
                 ret = -EINVAL;
-                goto done;
+                break;
             }
 
             qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
         } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
             void *host = host_from_stream_offset(f, addr, flags);
             if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
                 ret = -EINVAL;
-                goto done;
+                break;
             }
 
             if (load_xbzrle(f, addr, host) < 0) {
+                error_report("Failed to decompress XBZRLE page at "
+                             RAM_ADDR_FMT, addr);
                 ret = -EINVAL;
-                goto done;
+                break;
             }
         } else if (flags & RAM_SAVE_FLAG_HOOK) {
             ram_control_load_hook(f, flags);
+        } else if (flags & RAM_SAVE_FLAG_EOS) {
+            /* normal exit */
+            break;
+        } else {
+            error_report("Unknown migration flags: %#x", flags);
+            ret = -EINVAL;
+            break;
         }
-        error = qemu_file_get_error(f);
-        if (error) {
-            ret = error;
-            goto done;
-        }
-    } while (!(flags & RAM_SAVE_FLAG_EOS));
+        ret = qemu_file_get_error(f);
+    }
 
-done:
     DPRINTF("Completed load of VM with exit code %d seq iteration "
             "%" PRIu64 "\n", ret, seq_iter);
     return ret;

diff --git a/migration.c b/migration.c
index bd1fb912ae8a163963f11b0d053196ab1a573094..26f4b65e0f0e7f81b6ac4b6d32429556b379791f 100644 (file)
--- a/migration.c
+++ b/migration.c
@@ -98,7 +98,7 @@ static void process_incoming_migration_co(void *opaque)
     qemu_fclose(f);
     free_xbzrle_decoded_buf();
     if (ret < 0) {
-        fprintf(stderr, "load of migration failed\n");
+        error_report("load of migration failed: %s", strerror(-ret));
         exit(EXIT_FAILURE);
     }
     qemu_announce_self();