[PATCH v2] mm/gup: Fix memory leak in __gup_benchmark_ioctl

From: Navid Emamdoost <navid.emamdoost@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Keith Busch <keith.busch@intel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: emamd001@umn.edu, jhubbard@nvidia.com,
	Navid Emamdoost <navid.emamdoost@gmail.com>
Subject: [PATCH v2] mm/gup: Fix memory leak in __gup_benchmark_ioctl
Date: Fri, 13 Dec 2019 16:37:41 -0600	[thread overview]
Message-ID: <20191213223751.4089-1-navid.emamdoost@gmail.com> (raw)
In-Reply-To: <9a692d27-4654-f1fc-d4c5-c6efba02c8a9@nvidia.com>

In the implementation of __gup_benchmark_ioctl() the allocated pages
should be released before returning in case of an invalid cmd. Release
pages via kvfree() by goto done.

Fixes: 714a3a1ebafe ("mm/gup_benchmark.c: add additional pinning methods")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
Changes in v2:
	-- added goto and ret value instead of return -1.
---
 mm/gup_benchmark.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c
index b160638f647e..b773b2568544 100644
--- a/mm/gup_benchmark.c
+++ b/mm/gup_benchmark.c
@@ -24,7 +24,7 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 {
 	ktime_t start_time, end_time;
 	unsigned long i, nr_pages, addr, next;
-	int nr;
+	int nr, ret = 0;
 	struct page **pages;
 
 	if (gup->size > ULONG_MAX)
@@ -63,8 +63,8 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 					    NULL);
 			break;
 		default:
-			kvfree(pages);
-			return -1;
+			ret = -EINVAL;
+			goto done;
 		}
 
 		if (nr <= 0)
@@ -85,8 +85,9 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 	end_time = ktime_get();
 	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
 
+done:
 	kvfree(pages);
-	return 0;
+	return ret;
 }
 
 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
-- 
2.17.1

