[PATCH 5.4 234/270] 9p: Fix memory leak in v9fs_mount

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Zheng Bin <zhengbin13@xxxxxxxxxx>

commit cb0aae0e31c632c407a2cab4307be85a001d4d98 upstream.

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@xxxxxxxxxx
Fixes: 60e78d2c993e ("9p: Add fscache support to 9p")
Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.32+
Signed-off-by: Zheng Bin <zhengbin13@xxxxxxxxxx>
Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/9p/v9fs.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -500,10 +500,9 @@ void v9fs_session_close(struct v9fs_sess
 	}
 
 #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);