kvm tools, 9p: Fix memory leak in virtio_p9_walk()

This patch fixes the following valgrind reported memory leak in
virtio_9p_walk():

  ==6689== 1,058 bytes in 134 blocks are definitely lost in loss record 39 of 47
  ==6689==    at 0x4A0649D: malloc (vg_replace_malloc.c:236)
  ==6689==    by 0x4116A9: virtio_p9_pdu_readf (9p-pdu.c:110)
  ==6689==    by 0x40FB9F: virtio_p9_walk (9p.c:305)
  ==6689==    by 0x410E73: virtio_p9_do_io (9p.c:1151)
  ==6689==    by 0x40DB45: thread_pool__threadfunc (threadpool.c:56)
  ==6689==    by 0x3DE7007B30: start_thread (in /lib64/libpthread-2.14.so)
  ==6689==    by 0x3DE68DFD2C: clone (in /lib64/libc-2.14.so)

Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
index 8e37925d07d8e932d6afbf39fbffd4214b88c19d..3d1c624b7062db40d130d835cda8bf70bb2bacc5 100644 (file)
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -280,7 +280,6 @@ static void virtio_p9_walk(struct p9_dev *p9dev,
 {
        u8 i;
        u16 nwqid;
-       char *str;
        u16 nwname;
        struct p9_qid wqid;
        struct p9_fid *new_fid;
@@ -301,11 +300,15 @@ static void virtio_p9_walk(struct p9_dev *p9dev,
                        struct stat st;
                        char tmp[PATH_MAX] = {0};
                        char full_path[PATH_MAX];
+                       char *str;
 
                        virtio_p9_pdu_readf(pdu, "s", &str);
 
                        /* Format the new path we're 'walk'ing into */
                        sprintf(tmp, "%s/%s", new_fid->path, str);
+
+                       free(str);
+
                        if (lstat(rel_to_abs(p9dev, tmp, full_path), &st) < 0)
                                goto err_out;