release/5.2.35/mm-gup-fix-memory-leak-in-__gup_benchmark_ioctl.patch

From 9276b19f1ed52a7a9f07161c90c01af5ea837afd Mon Sep 17 00:00:00 2001
From: Navid Emamdoost <navid.emamdoost@gmail.com>
Date: Sat, 4 Jan 2020 13:00:12 -0800
Subject: [PATCH] mm/gup: fix memory leak in __gup_benchmark_ioctl

commit a7c46c0c0e3d62f2764cd08b90934cd2aaaf8545 upstream.

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().

[akpm@linux-foundation.org: rework code flow, return -EINVAL rather than -1]
Link: http://lkml.kernel.org/r/20191211174653.4102-1-navid.emamdoost@gmail.com
Fixes: 714a3a1ebafe ("mm/gup_benchmark.c: add additional pinning methods")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c
index 7dd602d7f8db..ad9d5b1c4473 100644
--- a/mm/gup_benchmark.c
+++ b/mm/gup_benchmark.c
@@ -26,6 +26,7 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 	unsigned long i, nr_pages, addr, next;
 	int nr;
 	struct page **pages;
+	int ret = 0;
 
 	if (gup->size > ULONG_MAX)
 		return -EINVAL;
@@ -63,7 +64,9 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 					    NULL);
 			break;
 		default:
-			return -1;
+			kvfree(pages);
+			ret = -EINVAL;
+			goto out;
 		}
 
 		if (nr <= 0)
@@ -85,7 +88,8 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
 	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
 
 	kvfree(pages);
-	return 0;
+out:
+	return ret;
 }
 
 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
-- 
2.7.4