9p: Fix memory leak in v9fs_mount

v9fs_mount
  v9fs_session_init
    v9fs_cache_session_get_cookie
      v9fs_random_cachetag                     -->alloc cachetag
      v9ses->fscache = fscache_acquire_cookie  -->maybe NULL
  sb = sget                                    -->fail, goto clunk
clunk_fid:
  v9fs_session_close
    if (v9ses->fscache)                        -->NULL
      kfree(v9ses->cachetag)

Thus memleak happens.

Link: http://lkml.kernel.org/r/20200615012153.89538-1-zhengbin13@huawei.com
Fixes: 60e78d2c993e ("9p: Add fscache support to 9p")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 15a99f9c725320eb1571cdf23f29d97d187fffcb..39def020a074b7fab442f60216916ae3c3ac6a7b 100644 (file)
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -500,10 +500,9 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
        }
 
 #ifdef CONFIG_9P_FSCACHE
-       if (v9ses->fscache) {
+       if (v9ses->fscache)
                v9fs_cache_session_put_cookie(v9ses);
-               kfree(v9ses->cachetag);
-       }
+       kfree(v9ses->cachetag);
 #endif
        kfree(v9ses->uname);
        kfree(v9ses->aname);