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authorSeunghun Han <kkamagui@gmail.com>2017-04-26 11:18:08 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-27 01:31:00 +0300
commit3b2d69114fefa474fca542e51119036dceb4aa6f (patch)
treeeaa7332d633dc3ae738d48f0c8130b83a06eae3d /drivers
parent2e337c72a3c24f0cf9bf639dc93de0f887d56dba (diff)
downloadlinux-3b2d69114fefa474fca542e51119036dceb4aa6f.tar.xz
ACPICA: Namespace: fix operand cache leak
ACPICA commit a23325b2e583556eae88ed3f764e457786bf4df6 I found some ACPI operand cache leaks in ACPI early abort cases. Boot log of ACPI operand cache leak is as follows: >[ 0.174332] ACPI: Added _OSI(Module Device) >[ 0.175504] ACPI: Added _OSI(Processor Device) >[ 0.176010] ACPI: Added _OSI(3.0 _SCP Extensions) >[ 0.177032] ACPI: Added _OSI(Processor Aggregator Device) >[ 0.178284] ACPI: SCI (IRQ16705) allocation failed >[ 0.179352] ACPI Exception: AE_NOT_ACQUIRED, Unable to install System Control Interrupt handler (20160930/evevent-131) >[ 0.180008] ACPI: Unable to start the ACPI Interpreter >[ 0.181125] ACPI Error: Could not remove SCI handler (20160930/evmisc-281) >[ 0.184068] kmem_cache_destroy Acpi-Operand: Slab cache still has objects >[ 0.185358] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc3 #2 >[ 0.186820] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006 >[ 0.188000] Call Trace: >[ 0.188000] ? dump_stack+0x5c/0x7d >[ 0.188000] ? kmem_cache_destroy+0x224/0x230 >[ 0.188000] ? acpi_sleep_proc_init+0x22/0x22 >[ 0.188000] ? acpi_os_delete_cache+0xa/0xd >[ 0.188000] ? acpi_ut_delete_caches+0x3f/0x7b >[ 0.188000] ? acpi_terminate+0x5/0xf >[ 0.188000] ? acpi_init+0x288/0x32e >[ 0.188000] ? __class_create+0x4c/0x80 >[ 0.188000] ? video_setup+0x7a/0x7a >[ 0.188000] ? do_one_initcall+0x4e/0x1b0 >[ 0.188000] ? kernel_init_freeable+0x194/0x21a >[ 0.188000] ? rest_init+0x80/0x80 >[ 0.188000] ? kernel_init+0xa/0x100 >[ 0.188000] ? ret_from_fork+0x25/0x30 When early abort is occurred due to invalid ACPI information, Linux kernel terminates ACPI by calling acpi_terminate() function. The function calls acpi_ns_terminate() function to delete namespace data and ACPI operand cache (acpi_gbl_module_code_list). But the deletion code in acpi_ns_terminate() function is wrapped in ACPI_EXEC_APP definition, therefore the code is only executed when the definition exists. If the define doesn't exist, ACPI operand cache (acpi_gbl_module_code_list) is leaked, and stack dump is shown in kernel log. This causes a security threat because the old kernel (<= 4.9) shows memory locations of kernel functions in stack dump, therefore kernel ASLR can be neutralized. To fix ACPI operand leak for enhancing security, I made a patch which removes the ACPI_EXEC_APP define in acpi_ns_terminate() function for executing the deletion code unconditionally. Link: https://github.com/acpica/acpica/commit/a23325b2 Signed-off-by: Seunghun Han <kkamagui@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/acpica/nsutils.c23
1 files changed, 9 insertions, 14 deletions
diff --git a/drivers/acpi/acpica/nsutils.c b/drivers/acpi/acpica/nsutils.c
index 661676714f7b..b5a291488e3f 100644
--- a/drivers/acpi/acpica/nsutils.c
+++ b/drivers/acpi/acpica/nsutils.c
@@ -594,25 +594,20 @@ struct acpi_namespace_node *acpi_ns_validate_handle(acpi_handle handle)
void acpi_ns_terminate(void)
{
acpi_status status;
+ union acpi_operand_object *prev;
+ union acpi_operand_object *next;
ACPI_FUNCTION_TRACE(ns_terminate);
-#ifdef ACPI_EXEC_APP
- {
- union acpi_operand_object *prev;
- union acpi_operand_object *next;
+ /* Delete any module-level code blocks */
- /* Delete any module-level code blocks */
-
- next = acpi_gbl_module_code_list;
- while (next) {
- prev = next;
- next = next->method.mutex;
- prev->method.mutex = NULL; /* Clear the Mutex (cheated) field */
- acpi_ut_remove_reference(prev);
- }
+ next = acpi_gbl_module_code_list;
+ while (next) {
+ prev = next;
+ next = next->method.mutex;
+ prev->method.mutex = NULL; /* Clear the Mutex (cheated) field */
+ acpi_ut_remove_reference(prev);
}
-#endif
/*
* Free the entire namespace -- all nodes and all objects