net: Forbid dealing with packets when VM is not running

[mirror_qemu.git] / block / qcow2-snapshot.c

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 87fbfe13a43ebf5c0085a7f84a2e77d920bd6ecb..f52d7fdd225479987365a2a3b4b67d3ef981093f 100644 (file)
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -58,7 +58,7 @@ int qcow2_read_snapshots(BlockDriverState *bs)
     }
 
     offset = s->snapshots_offset;
-    s->snapshots = g_malloc0(s->nb_snapshots * sizeof(QCowSnapshot));
+    s->snapshots = g_new0(QCowSnapshot, s->nb_snapshots);
 
     for(i = 0; i < s->nb_snapshots; i++) {
         /* Read statically sized part of the snapshot header */
@@ -116,8 +116,14 @@ int qcow2_read_snapshots(BlockDriverState *bs)
         }
         offset += name_size;
         sn->name[name_size] = '\0';
+
+        if (offset - s->snapshots_offset > QCOW_MAX_SNAPSHOTS_SIZE) {
+            ret = -EFBIG;
+            goto fail;
+        }
     }
 
+    assert(offset - s->snapshots_offset <= INT_MAX);
     s->snapshots_size = offset - s->snapshots_offset;
     return 0;
 
@@ -138,7 +144,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
         uint32_t nb_snapshots;
         uint64_t snapshots_offset;
     } QEMU_PACKED header_data;
-    int64_t offset, snapshots_offset;
+    int64_t offset, snapshots_offset = 0;
     int ret;
 
     /* compute the size of the snapshots */
@@ -150,7 +156,14 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
         offset += sizeof(extra);
         offset += strlen(sn->id_str);
         offset += strlen(sn->name);
+
+        if (offset > QCOW_MAX_SNAPSHOTS_SIZE) {
+            ret = -EFBIG;
+            goto fail;
+        }
     }
+
+    assert(offset <= INT_MAX);
     snapshots_size = offset;
 
     /* Allocate space for the new snapshot list */
@@ -368,7 +381,12 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     sn->l1_table_offset = l1_table_offset;
     sn->l1_size = s->l1_size;
 
-    l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
+    l1_table = g_try_new(uint64_t, s->l1_size);
+    if (s->l1_size && l1_table == NULL) {
+        ret = -ENOMEM;
+        goto fail;
+    }
+
     for(i = 0; i < s->l1_size; i++) {
         l1_table[i] = cpu_to_be64(s->l1_table[i]);
     }
@@ -399,7 +417,7 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     }
 
     /* Append the new snapshot to the snapshot list */
-    new_snapshot_list = g_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
+    new_snapshot_list = g_new(QCowSnapshot, s->nb_snapshots + 1);
     if (s->snapshots) {
         memcpy(new_snapshot_list, s->snapshots,
                s->nb_snapshots * sizeof(QCowSnapshot));
@@ -486,7 +504,11 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
      * Decrease the refcount referenced by the old one only when the L1
      * table is overwritten.
      */
-    sn_l1_table = g_malloc0(cur_l1_bytes);
+    sn_l1_table = g_try_malloc0(cur_l1_bytes);
+    if (cur_l1_bytes && sn_l1_table == NULL) {
+        ret = -ENOMEM;
+        goto fail;
+    }
 
     ret = bdrv_pread(bs->file, sn->l1_table_offset, sn_l1_table, sn_l1_bytes);
     if (ret < 0) {
@@ -639,7 +661,7 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
         return s->nb_snapshots;
     }
 
-    sn_tab = g_malloc0(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
+    sn_tab = g_new0(QEMUSnapshotInfo, s->nb_snapshots);
     for(i = 0; i < s->nb_snapshots; i++) {
         sn_info = sn_tab + i;
         sn = s->snapshots + i;
@@ -680,18 +702,26 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs,
     sn = &s->snapshots[snapshot_index];
 
     /* Allocate and read in the snapshot's L1 table */
-    new_l1_bytes = s->l1_size * sizeof(uint64_t);
-    new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512));
+    if (sn->l1_size > QCOW_MAX_L1_SIZE) {
+        error_setg(errp, "Snapshot L1 table too large");
+        return -EFBIG;
+    }
+    new_l1_bytes = sn->l1_size * sizeof(uint64_t);
+    new_l1_table = qemu_try_blockalign(bs->file,
+                                       align_offset(new_l1_bytes, 512));
+    if (new_l1_table == NULL) {
+        return -ENOMEM;
+    }
 
     ret = bdrv_pread(bs->file, sn->l1_table_offset, new_l1_table, new_l1_bytes);
     if (ret < 0) {
         error_setg(errp, "Failed to read l1 table for snapshot");
-        g_free(new_l1_table);
+        qemu_vfree(new_l1_table);
         return ret;
     }
 
     /* Switch the L1 table */
-    g_free(s->l1_table);
+    qemu_vfree(s->l1_table);
 
     s->l1_size = sn->l1_size;
     s->l1_table_offset = sn->l1_table_offset;