2022-09-07 06:57:07

by Jianglei Nie

Subject: [PATCH] PM: hibernate: Fix potential memory leak in hibernate_preallocate_memory() and prepare_highmem_image()

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 <[email protected]>
---
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

2022-10-25 16:21:51

by Rafael J. Wysocki

Subject: Re: [PATCH] PM: hibernate: Fix potential memory leak in hibernate_preallocate_memory() and prepare_highmem_image()

On Wed, Sep 7, 2022 at 8:43 AM Jianglei Nie <[email protected]> wrote:
>
> 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().

swsusp_free() called at the end is expected to free all of these
pages. Doesn't it do that?

> Fix it by calling memory_bm_free() at the right time.
>
> Signed-off-by: Jianglei Nie <[email protected]>
> ---
> 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
>