[Qemu-devel] [PATCH] migration: Fix free XBZRLE decoded_buf wrong

[Gonglei (Arei)]

Hi,

When qemu do live migration with xbzrle, qemu malloc decoded_buf
at destniation end but free it at source end.It will crash qemu
by double free error in some scenarios.

Signed-off-by: chenliang <address@hidden>
---
 arch_init.c                   |    9 ++++++++-
 include/migration/migration.h |    1 +
 migration.c                   |    1 +
 3 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index e0acbc5..0453f84 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -572,6 +572,14 @@ uint64_t ram_bytes_total(void)
     return total;
 }
 
+void free_xbzrle_decoded_buf(void)
+{
+    if (XBZRLE.decoded_buf) {
+        g_free(XBZRLE.decoded_buf);
+        XBZRLE.decoded_buf = NULL;
+    }
+}
+
 static void migration_end(void)
 {
     if (migration_bitmap) {
@@ -585,7 +593,6 @@ static void migration_end(void)
         g_free(XBZRLE.cache);
         g_free(XBZRLE.encoded_buf);
         g_free(XBZRLE.current_buf);
-        g_free(XBZRLE.decoded_buf);
         XBZRLE.cache = NULL;
     }
 }
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 140e6b4..9314511 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -98,6 +98,7 @@ MigrationState *migrate_get_current(void);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_transferred(void);
 uint64_t ram_bytes_total(void);
+void free_xbzrle_decoded_buf(void);
 
 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 
diff --git a/migration.c b/migration.c
index 2b1ab20..310c8bf 100644
--- a/migration.c
+++ b/migration.c
@@ -104,6 +104,7 @@ static void process_incoming_migration_co(void *opaque)
 
     ret = qemu_loadvm_state(f);
     qemu_fclose(f);
+    free_xbzrle_decoded_buf();
     if (ret < 0) {
         fprintf(stderr, "load of migration failed\n");
         exit(EXIT_FAILURE);
-- 
1.6.0.2

Best regards,
-Gonglei