Prev: [RFC][PATCH 1/2] pidns: Add a flag to indicate a pid namespace is dead.
Next: [RFC][PATCH 2/2] pidns: Remove proc flush races when a pid namespaces are exiting.
From: Axel Lin on 9 Jul 2010 00:40
When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
the caller must kfree the returned buffer if AE_OK is returned.

Call Trace:
wmab_execute
-> wmi_evaluate_method
-> acpi_evaluate_object

Thus if callers of wmab_execute() pass ACPI_ALLOCATE_BUFFER,
the return buffer must be kfreed if wmab_execute return AE_OK.

Signed-off-by: Axel Lin <axel.lin(a)gmail.com>
---
drivers/platform/x86/acer-wmi.c | 11 ++++++++++-
1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index 1ea6c43..3f44446 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -555,6 +555,7 @@ static acpi_status AMW0_find_mailled(void)
obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
+ kfree(out.pointer);
return AE_ERROR;
}

@@ -598,6 +599,7 @@ static acpi_status AMW0_set_capabilities(void)
obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
+ kfree(out.pointer);
return AE_ERROR;
}

@@ -607,15 +609,22 @@ static acpi_status AMW0_set_capabilities(void)
args.ebx = 2 << 8;
args.ebx |= ACER_AMW0_BLUETOOTH_MASK;

+ /*
+ * It's ok to use existing buffer for next wmab_execute call.
+ * But we need to kfree(out.pointer) if next wmab_execute fail.
+ */
status = wmab_execute(&args, &out);
- if (ACPI_FAILURE(status))
+ if (ACPI_FAILURE(status)) {
+ kfree(out.pointer);
return status;
+ }

obj = (union acpi_object *) out.pointer;
if (obj && obj->type == ACPI_TYPE_BUFFER
&& obj->buffer.length == sizeof(struct wmab_ret)) {
ret = *((struct wmab_ret *) obj->buffer.pointer);
} else {
+ kfree(out.pointer);
return AE_ERROR;
}

--
1.5.4.3



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: [RFC][PATCH 1/2] pidns: Add a flag to indicate a pid namespace is dead.
Next: [RFC][PATCH 2/2] pidns: Remove proc flush races when a pid namespaces are exiting.