From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 2 Feb 2023 14:09:18 +0000 (+0100)
Subject: HV: hv_balloon: fix memory leak with using debugfs_lookup()
X-Git-Tag: baikal/aarch64/sdk6.1~47
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=383255c1bb7906535ccbc18ddcc75ff1fb5f7db0;p=kernel.git

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 6c127f061f06d..f98c849096f7b 100644
--- 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