From patchwork Wed Jun 14 11:08:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Seunghun Han X-Patchwork-Id: 9786125 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2082A602C9 for ; Wed, 14 Jun 2017 11:09:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 19CF3285DA for ; Wed, 14 Jun 2017 11:09:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0E168285E7; Wed, 14 Jun 2017 11:09:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 71BF0285DA for ; Wed, 14 Jun 2017 11:09:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751771AbdFNLJu (ORCPT ); Wed, 14 Jun 2017 07:09:50 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:34786 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750756AbdFNLJs (ORCPT ); Wed, 14 Jun 2017 07:09:48 -0400 Received: by mail-pf0-f196.google.com with SMTP id d5so14016015pfe.1; Wed, 14 Jun 2017 04:09:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=P5du9gUX0FGP8jIvGpQg09m+enAZ1+wRq3OkVtaGhSo=; b=PAL5fr5iWMR3rXQLXDUm6rOLLF+FHOZC4oCCTw2QahJYCoCHoLtwwcvx4yXPj2QMBr 33bFyC/5VmLlZeIn93o26c9k8NYvdAaxOXmPMbwP1AEXP3NdJe1ssJh/O6sz/19OEzIO Sl09Q8MGzOhXRUHdRrPPPrKHWO/opM+C2BOHfmW1a0EC7Wsrv9wdpR494j6rhIB1fH0L +uhw2i+zipcg723Lj5mnJwVXG9W7TNHe3SeLQE/8HN63twikHdnCSEf3mi/5QNVKL+ev j9QDW3y/gfgLr+ubmpTYsGc1RV4/BmctXnC4D7bUvOLvI93TmN5WFoWEgy0FOQqaFczo cU+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=P5du9gUX0FGP8jIvGpQg09m+enAZ1+wRq3OkVtaGhSo=; b=mgq9Q376BwpGsOFpyfkLqyzp09pLNYU5nLRksjG/lRvhgW/rcCp35flvYUax4ls9zU UbkMw501lZ+D+c/8RWu5dbSsRMgofwRzFZKr2Q9wgyM1RNDPuE6H7ANI3yllpVerSWZX 9SGet7lVzsGdwIv03ZP4u/HnNJlRtJt1urRElYGv6veFLKMv6owEgnqfMYnmOVG8RmI7 wr9giYGP+mF5V/hB7tLQWLe0CrJxRGr0edNC8GWMzkK/aUz4tTlDxc8v0BzJ71QmjovA MKB2ocGlt5uWJ9+PGi9IbQ2Za1pits+8j6egcRQpQXEy7RNoV1DudvQ1YdYh5kM+gunU vP+w== X-Gm-Message-State: AKS2vOwFEdeEIQC30HhjVuEPFOvLlYB8m4xWd0LIMWlmDneIEkhvA+Xm qd1Pq+fdVFLvUw== X-Received: by 10.98.142.17 with SMTP id k17mr38970pfe.139.1497438587956; Wed, 14 Jun 2017 04:09:47 -0700 (PDT) Received: from localhost.localdomain ([175.203.71.232]) by smtp.gmail.com with ESMTPSA id 189sm1440128pgj.67.2017.06.14.04.09.44 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 14 Jun 2017 04:09:46 -0700 (PDT) From: Seunghun Han To: lv.zheng@intel.com, robert.moore@intel.com, rafael.j.wysocki@intel.com Cc: linux-acpi@vger.kernel.org, devel@acpica.org, linux-kernel@vger.kernel.org, Seunghun Han Subject: [PATCH] acpi: acpica: fix acpi parse and parseext cache leaks Date: Wed, 14 Jun 2017 20:08:10 +0900 Message-Id: <1497438490-22268-1-git-send-email-kkamagui@gmail.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP I'm Seunghun Han, and I work for National Security Research Institute of South Korea. I have been doing a research on ACPI and found an ACPI cache leak in ACPI early abort cases. Boot log of ACPI cache leak is as follows: [ 0.352414] ACPI: Added _OSI(Module Device) [ 0.353182] ACPI: Added _OSI(Processor Device) [ 0.353182] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.353182] ACPI: Added _OSI(Processor Aggregator Device) [ 0.356028] ACPI: Unable to start the ACPI Interpreter [ 0.356799] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) [ 0.360215] kmem_cache_destroy Acpi-State: Slab cache still has objects [ 0.360648] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #10 [ 0.361273] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 0.361873] Call Trace: [ 0.362243] ? dump_stack+0x5c/0x81 [ 0.362591] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.362944] ? acpi_sleep_proc_init+0x27/0x27 [ 0.363296] ? acpi_os_delete_cache+0xa/0x10 [ 0.363646] ? acpi_ut_delete_caches+0x6d/0x7b [ 0.364000] ? acpi_terminate+0xa/0x14 [ 0.364000] ? acpi_init+0x2af/0x34f [ 0.364000] ? __class_create+0x4c/0x80 [ 0.364000] ? video_setup+0x7f/0x7f [ 0.364000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.364000] ? do_one_initcall+0x4e/0x1a0 [ 0.364000] ? kernel_init_freeable+0x189/0x20a [ 0.364000] ? rest_init+0xc0/0xc0 [ 0.364000] ? kernel_init+0xa/0x100 [ 0.364000] ? ret_from_fork+0x25/0x30 I analyzed this memory leak detailed. I found that “Acpi-State” cache and “Acpi-Parse” cache were merged because the size of cache objects was same slab cache size. I finally found “Acpi-Parse” cache and “Acpi-ParseExt” cache were leaked using SLAB_NEVER_MERGE flag in kmem_cache_create() function. Real ACPI cache leak point is as follows: [ 0.360101] ACPI: Added _OSI(Module Device) [ 0.360101] ACPI: Added _OSI(Processor Device) [ 0.360101] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.361043] ACPI: Added _OSI(Processor Aggregator Device) [ 0.364016] ACPI: Unable to start the ACPI Interpreter [ 0.365061] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) [ 0.368174] kmem_cache_destroy Acpi-Parse: Slab cache still has objects [ 0.369332] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #8 [ 0.371256] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 0.372000] Call Trace: [ 0.372000] ? dump_stack+0x5c/0x81 [ 0.372000] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.372000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.372000] ? acpi_os_delete_cache+0xa/0x10 [ 0.372000] ? acpi_ut_delete_caches+0x56/0x7b [ 0.372000] ? acpi_terminate+0xa/0x14 [ 0.372000] ? acpi_init+0x2af/0x34f [ 0.372000] ? __class_create+0x4c/0x80 [ 0.372000] ? video_setup+0x7f/0x7f [ 0.372000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.372000] ? do_one_initcall+0x4e/0x1a0 [ 0.372000] ? kernel_init_freeable+0x189/0x20a [ 0.372000] ? rest_init+0xc0/0xc0 [ 0.372000] ? kernel_init+0xa/0x100 [ 0.372000] ? ret_from_fork+0x25/0x30 [ 0.388039] kmem_cache_destroy Acpi-ParseExt: Slab cache still has objects [ 0.389063] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #8 [ 0.390557] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 0.392000] Call Trace: [ 0.392000] ? dump_stack+0x5c/0x81 [ 0.392000] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.392000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.392000] ? acpi_os_delete_cache+0xa/0x10 [ 0.392000] ? acpi_ut_delete_caches+0x6d/0x7b [ 0.392000] ? acpi_terminate+0xa/0x14 [ 0.392000] ? acpi_init+0x2af/0x34f [ 0.392000] ? __class_create+0x4c/0x80 [ 0.392000] ? video_setup+0x7f/0x7f [ 0.392000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.392000] ? do_one_initcall+0x4e/0x1a0 [ 0.392000] ? kernel_init_freeable+0x189/0x20a [ 0.392000] ? rest_init+0xc0/0xc0 [ 0.392000] ? kernel_init+0xa/0x100 [ 0.392000] ? 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_ut_delete_caches() function to delete local caches (acpi_gbl_namespace_ cache, state_cache, operand_cache, ps_node_cache, ps_node_ext_cache). But the deletion codes in acpi_ut_delete_caches() function only delete slab caches using kmem_cache_destroy() function, therefore the cache objects should be flushed before acpi_ut_delete_caches() function. “Acpi-Parse” cache and “Acpi-ParseExt” cache are used in an AML parse function, acpi_ps_parse_loop(). The function should have flush codes to handle an error state due to invalid AML codes. This cache leak has a security threat because an old kernel (<= 4.9) shows memory locations of kernel functions in stack dump. Some malicious users could use this information to neutralize kernel ASLR. To fix ACPI cache leak for enhancing security, I made a patch which has flush codes in acpi_ps_parse_loop() function. I hope that this patch improves the security of Linux kernel. Thank you. Signed-off-by: Seunghun Han --- drivers/acpi/acpica/psloop.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c index b422400..5d06383 100644 --- a/drivers/acpi/acpica/psloop.c +++ b/drivers/acpi/acpica/psloop.c @@ -658,5 +658,18 @@ acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state) } /* while parser_state->Aml */ status = acpi_ps_complete_final_op(walk_state, op, status); + if (ACPI_FAILURE(status)) { + /* Flush pushed op objects */ + + do { + acpi_ps_pop_scope(&(walk_state->parser_state), &op, + &walk_state->arg_types, + &walk_state->arg_count); + if (op) { + acpi_ps_complete_this_op(walk_state, op); + } + } while (op); + } + return_ACPI_STATUS(status); }