Re: [Qemu-devel] [PATCH v2] tap: fix memory leak on success to create a tap device

[Jason Wang]

On 2018年05月31日 15:28, wangyunjian wrote:

From: Yunjian Wang <wangyunj...@huawei.com>

The memory leak on success to create a tap device. And the nfds and
nvhosts may not be the same and need to be processed separately.

Fixes: 07825977 ("tap: fix memory leak on failure to create a multiqueue tap 
device")
Fixes: 264986e2 ("tap: multiqueue support")

CC: QEMU Stable <qemu-sta...@nongnu.org>
Signed-off-by: Yunjian Wang <wangyunj...@huawei.com>
---
v2:
  -add commit log and cc qemu-stable with fixes tags
---

Applied.

Thanks

  net/tap.c | 16 ++++++++++------
  1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index de05f20..6d7710f 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -803,7 +803,8 @@ int net_init_tap(const Netdev *netdev, const char *name,
      } else if (tap->has_fds) {
          char **fds;
          char **vhost_fds;
-        int nfds, nvhosts;
+        int nfds = 0, nvhosts = 0;
+        int ret = 0;

if (tap->has_ifname || tap->has_script || tap->has_downscript ||

              tap->has_vnet_hdr || tap->has_helper || tap->has_queues ||
@@ -823,6 +824,7 @@ int net_init_tap(const Netdev *netdev, const char *name,
              if (nfds != nvhosts) {
                  error_setg(errp, "The number of fds passed does not match "
                             "the number of vhostfds passed");
+                ret = -1;
                  goto free_fail;
              }
          }
@@ -831,6 +833,7 @@ int net_init_tap(const Netdev *netdev, const char *name,
              fd = monitor_fd_param(cur_mon, fds[i], &err);
              if (fd == -1) {
                  error_propagate(errp, err);
+                ret = -1;
                  goto free_fail;
              }

@@ -841,6 +844,7 @@ int net_init_tap(const Netdev *netdev, const char *name,

              } else if (vnet_hdr != tap_probe_vnet_hdr(fd)) {
                  error_setg(errp,
                             "vnet_hdr not consistent across given tap fds");
+                ret = -1;
                  goto free_fail;
              }

@@ -850,21 +854,21 @@ int net_init_tap(const Netdev *netdev, const char *name,

                               vnet_hdr, fd, &err);
              if (err) {
                  error_propagate(errp, err);
+                ret = -1;
                  goto free_fail;
              }
          }
-        g_free(fds);
-        g_free(vhost_fds);
-        return 0;

free_fail:

+        for (i = 0; i < nvhosts; i++) {
+            g_free(vhost_fds[i]);
+        }
          for (i = 0; i < nfds; i++) {
              g_free(fds[i]);
-            g_free(vhost_fds[i]);
          }
          g_free(fds);
          g_free(vhost_fds);
-        return -1;
+        return ret;
      } else if (tap->has_helper) {
          if (tap->has_ifname || tap->has_script || tap->has_downscript ||
              tap->has_vnet_hdr || tap->has_queues || tap->has_vhostfds) {