2010-07-06 02:55:30

by Axel Lin

Subject: [PATCH] acer-wmi: fix memory leaks in WMID_set_capabilities and get_wmid_devices

When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
the caller must kfree the returned buffer if AE_OK is returned.

The callers of wmi_query_block() pass ACPI_ALLOCATE_BUFFER,
and thus must check its return value before accessing
or kfree() on the buffer.

This patch adds a missing kfree(out.pointer) before exit
WMID_set_capabilities() and get_wmid_devices().

Signed-off-by: Axel Lin <[email protected]>
---
drivers/platform/x86/acer-wmi.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 1ea6c43..fe644c6 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -772,6 +772,7 @@ static acpi_status WMID_set_capabilities(void)
obj->buffer.length == sizeof(u32)) {
devices = *((u32 *) obj->buffer.pointer);
} else {
+ kfree(out.pointer);
return AE_ERROR;
}

@@ -788,6 +789,7 @@ static acpi_status WMID_set_capabilities(void)
if (!(devices & 0x20))
max_brightness = 0x9;

+ kfree(out.pointer);
return status;
}

@@ -1095,6 +1097,7 @@ static u32 get_wmid_devices(void)
struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
union acpi_object *obj;
acpi_status status;
+ u32 devices = 0;

status = wmi_query_block(WMID_GUID2, 1, &out);
if (ACPI_FAILURE(status))
@@ -1103,10 +1106,11 @@ static u32 get_wmid_devices(void)
obj = (union acpi_object *) out.pointer;
if (obj && obj->type == ACPI_TYPE_BUFFER &&
obj->buffer.length == sizeof(u32)) {
- return *((u32 *) obj->buffer.pointer);
- } else {
- return 0;
+ devices = *((u32 *) obj->buffer.pointer);
}
+
+ kfree(out.pointer);
+ return devices;
}

/*
--
1.5.4.3

2010-07-06 07:22:56

by Carlos Corbacho

Subject: Re: [PATCH] acer-wmi: fix memory leaks in WMID_set_capabilities and get_wmid_devices

On Tuesday 06 July 2010 03:55:36 Axel Lin wrote:
> When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
> the caller must kfree the returned buffer if AE_OK is returned.
>
> The callers of wmi_query_block() pass ACPI_ALLOCATE_BUFFER,
> and thus must check its return value before accessing
> or kfree() on the buffer.
>
> This patch adds a missing kfree(out.pointer) before exit
> WMID_set_capabilities() and get_wmid_devices().
>
> Signed-off-by: Axel Lin <[email protected]>

Acked-by: Carlos Corbacho <[email protected]>

> ---
> drivers/platform/x86/acer-wmi.c | 10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/x86/acer-wmi.c
> b/drivers/platform/x86/acer-wmi.c index 1ea6c43..fe644c6 100644
> --- a/drivers/platform/x86/acer-wmi.c
> +++ b/drivers/platform/x86/acer-wmi.c
> @@ -772,6 +772,7 @@ static acpi_status WMID_set_capabilities(void)
> obj->buffer.length == sizeof(u32)) {
> devices = *((u32 *) obj->buffer.pointer);
> } else {
> + kfree(out.pointer);
> return AE_ERROR;
> }
>
> @@ -788,6 +789,7 @@ static acpi_status WMID_set_capabilities(void)
> if (!(devices & 0x20))
> max_brightness = 0x9;
>
> + kfree(out.pointer);
> return status;
> }
>
> @@ -1095,6 +1097,7 @@ static u32 get_wmid_devices(void)
> struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
> union acpi_object *obj;
> acpi_status status;
> + u32 devices = 0;
>
> status = wmi_query_block(WMID_GUID2, 1, &out);
> if (ACPI_FAILURE(status))
> @@ -1103,10 +1106,11 @@ static u32 get_wmid_devices(void)
> obj = (union acpi_object *) out.pointer;
> if (obj && obj->type == ACPI_TYPE_BUFFER &&
> obj->buffer.length == sizeof(u32)) {
> - return *((u32 *) obj->buffer.pointer);
> - } else {
> - return 0;
> + devices = *((u32 *) obj->buffer.pointer);
> }
> +
> + kfree(out.pointer);
> + return devices;
> }
>
> /*

--
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