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From:   Jianglei Nie <niejianglei2021@163.com>
To:     rafael@kernel.org
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jianglei Nie <niejianglei2021@163.com>
Subject: [PATCH] PM: hibernate: Fix potential memory leak in hibernate_preallocate_memory() and prepare_highmem_image()
Date:   Wed,  7 Sep 2022 14:43:11 +0800
Message-Id: <20220907064311.54475-1-niejianglei2021@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

hibernate_preallocate_memory() and prepare_highmem_image() allocates
memory chunk with memory_bm_create(). When the function gets some error
after memory_bm_create(), relavent memory should be released with
memory_bm_free().

Fix it by calling memory_bm_free() at the right time.

Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
 kernel/power/snapshot.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 2a406753af90..e5ec204ebe22 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1752,6 +1752,7 @@ int hibernate_preallocate_memory(void)
 
 	error = memory_bm_create(&copy_bm, GFP_IMAGE, PG_ANY);
 	if (error) {
+		memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
 		pr_err("Cannot allocate copy bitmap\n");
 		goto err_out;
 	}
@@ -2335,8 +2336,10 @@ static int prepare_highmem_image(struct memory_bitmap *bm,
 	if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
 		return -ENOMEM;
 
-	if (get_highmem_buffer(PG_SAFE))
+	if (get_highmem_buffer(PG_SAFE)) {
+		memory_bm_free(bm, PG_UNSAFE_CLEAR);
 		return -ENOMEM;
+	}
 
 	to_alloc = count_free_highmem_pages();
 	if (to_alloc > *nr_highmem_p)
-- 
2.25.1