HV: hv_balloon: fix memory leak with using debugfs_lookup()

commit 6dfb0771429a63db8561d44147f2bb76f93e1c86 upstream.

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Fixes: d47db11e20f5 ("Drivers: hv: Create debugfs file with hyper-v balloon usage information")
Cc: stable <stable@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230202140918.2289522-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 6c127f061f06db8ba763d616673551f5641132a6..f98c849096f7be0c066b2993f2f6eb1df99378a6 100644 (file)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1911,7 +1911,7 @@ static void  hv_balloon_debugfs_init(struct hv_dynmem_device *b)
 
 static void  hv_balloon_debugfs_exit(struct hv_dynmem_device *b)
 {
-       debugfs_remove(debugfs_lookup("hv-balloon", NULL));
+       debugfs_lookup_and_remove("hv-balloon", NULL);
 }
 
 #else