2023-09-24 17:26:02

by Kuan-Wei Chiu

Subject: [PATCH] efi: fix memory leak in krealloc failure handling

In the previous code, there was a memory leak issue where the
previously allocated memory was not freed upon a failed krealloc
operation. This patch addresses the problem by releasing the old memory
before setting the pointer to NULL in case of a krealloc failure. This
ensures that memory is properly managed and avoids potential memory
leaks.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
---
drivers/firmware/efi/efi.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index ce20a60676f0..1974f0ad32ba 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -273,9 +273,13 @@ static __init int efivar_ssdt_load(void)
if (status == EFI_NOT_FOUND) {
break;
} else if (status == EFI_BUFFER_TOO_SMALL) {
- name = krealloc(name, name_size, GFP_KERNEL);
- if (!name)
+ efi_char16_t *name_tmp =
+ krealloc(name, name_size, GFP_KERNEL);
+ if (!name_tmp) {
+ kfree(name);
return -ENOMEM;
+ }
+ name = name_tmp;
continue;
}

--
2.25.1

2023-10-13 10:33:13

by Ard Biesheuvel

Subject: Re: [PATCH] efi: fix memory leak in krealloc failure handling

On Sun, 24 Sept 2023 at 16:26, Kuan-Wei Chiu <[email protected]> wrote:
>
> In the previous code, there was a memory leak issue where the
> previously allocated memory was not freed upon a failed krealloc
> operation. This patch addresses the problem by releasing the old memory
> before setting the pointer to NULL in case of a krealloc failure. This
> ensures that memory is properly managed and avoids potential memory
> leaks.
>
> Signed-off-by: Kuan-Wei Chiu <[email protected]>
> ---
> drivers/firmware/efi/efi.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>

Queued as a fix

Thanks,

> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index ce20a60676f0..1974f0ad32ba 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -273,9 +273,13 @@ static __init int efivar_ssdt_load(void)
> if (status == EFI_NOT_FOUND) {
> break;
> } else if (status == EFI_BUFFER_TOO_SMALL) {
> - name = krealloc(name, name_size, GFP_KERNEL);
> - if (!name)
> + efi_char16_t *name_tmp =
> + krealloc(name, name_size, GFP_KERNEL);
> + if (!name_tmp) {
> + kfree(name);
> return -ENOMEM;
> + }
> + name = name_tmp;
> continue;
> }
>
> --
> 2.25.1
>