From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE98EC4727C for ; Wed, 30 Sep 2020 02:20:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90ACD20874 for ; Wed, 30 Sep 2020 02:20:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729446AbgI3CUs convert rfc822-to-8bit (ORCPT ); Tue, 29 Sep 2020 22:20:48 -0400 Received: from mga14.intel.com ([192.55.52.115]:15239 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726689AbgI3CUs (ORCPT ); Tue, 29 Sep 2020 22:20:48 -0400 IronPort-SDR: tn6Cz+KcKXajbA4ogzN4SjS3yGTwdX0bCATLCoTfNGpRnrI5KwZUKMTCnFAeD+wBsrJtL9m3ze VHclP0NFmE3A== X-IronPort-AV: E=McAfee;i="6000,8403,9759"; a="161562228" X-IronPort-AV: E=Sophos;i="5.77,320,1596524400"; d="scan'208";a="161562228" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2020 19:20:45 -0700 IronPort-SDR: viLIUotV/hOeJS/xXnINgmiZLlum3DqZcP2orypLACSqeejtNsq6C5OpNMAVO8hF7OhhpE3yR4 x4I6t5VP4uWw== X-IronPort-AV: E=Sophos;i="5.77,320,1596524400"; d="scan'208";a="494851100" Received: from xinpan-mobl.ger.corp.intel.com (HELO localhost) ([10.249.35.239]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2020 19:20:42 -0700 Date: Wed, 30 Sep 2020 05:20:40 +0300 From: Jarkko Sakkinen To: Mimi Zohar , tyhicks@linux.microsoft.com Cc: Kai-Heng Feng , linux-integrity@vger.kernel.org, open list Subject: Re: [Regression] "tpm: Require that all digests are present in TCG_PCR_EVENT2 structures" causes null pointer dereference Message-ID: <20200930022040.GG808399@linux.intel.com> References: <20200928140623.GA69515@linux.intel.com> <846fe4da67d05f57fba33e38c9a6e394e657adc3.camel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <846fe4da67d05f57fba33e38c9a6e394e657adc3.camel@linux.ibm.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, Sep 29, 2020 at 01:52:04PM -0400, Mimi Zohar wrote: > On Mon, 2020-09-28 at 22:16 +0800, Kai-Heng Feng wrote: > > Hi Jarkko, > > > > > On Sep 28, 2020, at 22:06, Jarkko Sakkinen wrote: > > > > > > On Mon, Sep 28, 2020 at 08:31:04PM +0800, Kai-Heng Feng wrote: > > >> Commit 7f3d176f5f7e "tpm: Require that all digests are present in > > >> TCG_PCR_EVENT2 structures" causes a null pointer dereference on all > > >> laptops I have: > > > > > > ... > > > > > >> [ 17.868849] BUG: kernel NULL pointer dereference, address: 000000000000002c > > >> [ 17.868852] #PF: supervisor read access in kernel mode > > >> [ 17.868854] #PF: error_code(0x0000) - not-present page > > >> [ 17.868855] PGD 0 P4D 0 > > >> [ 17.868858] Oops: 0000 [#1] SMP PTI > > >> [ 17.868860] CPU: 0 PID: 1873 Comm: fwupd Not tainted 5.8.0-rc6+ #25 > > >> [ 17.868861] Hardware name: LENOVO 20LAZ3TXCN/20LAZ3TXCN, BIOS N27ET38W (1.24 ) 11/28/2019 > > >> [ 17.868866] RIP: 0010:tpm2_bios_measurements_start+0x38/0x1f0 > > >> [ 17.868868] Code: 55 41 54 53 48 83 ec 30 4c 8b 16 65 48 8b 04 25 28 00 00 00 48 89 45 d0 48 8b 47 70 4c 8b a0 d0 06 00 00 48 8b 88 d8 06 00 00 <41> 8b 5c 24 1c 48 89 4d b0 48 89 d8 48 83 c3 20 4d 85 d2 75 31 4c > > >> [ 17.868869] RSP: 0018:ffff9da500a9fde0 EFLAGS: 00010282 > > >> [ 17.868871] RAX: ffff917d03dc4000 RBX: 0000000000000000 RCX: 0000000000000010 > > >> [ 17.868872] RDX: 0000000000001000 RSI: ffff917c99b19460 RDI: ffff917c99b19438 > > >> [ 17.868873] RBP: ffff9da500a9fe38 R08: ffffbda4ffa33fc0 R09: ffff917cbfeae4c0 > > >> [ 17.868874] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000010 > > >> [ 17.868875] R13: ffff917c99b19438 R14: ffff917c99b19460 R15: ffff917c99b19470 > > >> [ 17.868876] FS: 00007f9d80988b00(0000) GS:ffff917d07400000(0000) knlGS:0000000000000000 > > >> [ 17.868877] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > >> [ 17.868878] CR2: 000000000000002c CR3: 0000000219b12004 CR4: 00000000003606f0 > > >> [ 17.868879] Call Trace: > > >> [ 17.868884] seq_read+0x95/0x470 > > >> [ 17.868887] ? security_file_permission+0x150/0x160 > > >> [ 17.868889] vfs_read+0xaa/0x190 > > >> [ 17.868891] ksys_read+0x67/0xe0 > > >> [ 17.868893] __x64_sys_read+0x1a/0x20 > > >> [ 17.868896] do_syscall_64+0x52/0xc0 > > >> [ 17.868898] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > >> [ 17.868900] RIP: 0033:0x7f9d83be91dc > > >> [ 17.868901] Code: Bad RIP value. > > >> [ 17.868902] RSP: 002b:00007fff7f5e0250 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > > >> [ 17.868903] RAX: ffffffffffffffda RBX: 00005651d262f420 RCX: 00007f9d83be91dc > > >> [ 17.868904] RDX: 0000000000001000 RSI: 00007fff7f5e0350 RDI: 0000000000000010 > > >> [ 17.868905] RBP: 00007f9d83cc54a0 R08: 0000000000000000 R09: 00005651d26c1830 > > >> [ 17.868906] R10: 00005651d2582010 R11: 0000000000000246 R12: 0000000000001000 > > >> [ 17.868907] R13: 00007fff7f5e0350 R14: 0000000000000d68 R15: 00007f9d83cc48a0 > > >> [ 17.868909] Modules linked in: rfcomm ccm cmac algif_hash algif_skcipher af_alg snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic bnep joydev mei_hdcp wmi_bmof intel_rapl_msr intel_wmi_thunderbolt x86_pkg_temp_thermal intel_powerclamp coretemp nls_iso8859_1 kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper crypto_simd cryptd rapl input_leds intel_cstate snd_hda_intel snd_intel_dspcfg rmi_smbus iwlmvm snd_hda_codec serio_raw snd_hwdep mac80211 rmi_core snd_hda_core libarc4 uvcvideo snd_pcm videobuf2_vmalloc btusb videobuf2_memops iwlwifi videobuf2_v4l2 btrtl btbcm videobuf2_common btintel thunderbolt i915 bluetooth mei_me videodev thinkpad_acpi nvram cfg80211 ledtrig_audio mei mc ecdh_generic ecc i2c_algo_bit processor_thermal_device snd_seq_midi drm_kms_helper snd_seq_midi_event intel_soc_dts_iosf syscopyarea sysfillrect snd_rawmidi intel_pch_thermal sysimgblt intel_rapl_common intel_xhci_usb_role_switch fb_sys_fops u > cs > > i_acpi r > > o > > > les cec > > >> [ 17.868935] typec_ucsi typec nxp_nci_i2c snd_seq nxp_nci wmi nci nfc snd_timer snd_seq_device snd int3403_thermal soundcore int340x_thermal_zone video mac_hid int3400_thermal acpi_pad acpi_thermal_rel sch_fq_codel parport_pc ppdev lp parport drm ip_tables x_tables autofs4 btrfs blake2b_generic libcrc32c xor zstd_compress raid6_pq uas usb_storage psmouse e1000e nvme i2c_i801 i2c_smbus nvme_core intel_lpss_pci intel_lpss idma64 virt_dma pinctrl_sunrisepoint pinctrl_intel > > >> [ 17.868951] CR2: 000000000000002c > > >> [ 17.868953] ---[ end trace ee7716fff5dec2fb ]--- > > >> [ 17.868955] RIP: 0010:tpm2_bios_measurements_start+0x38/0x1f0 > > >> [ 17.868957] Code: 55 41 54 53 48 83 ec 30 4c 8b 16 65 48 8b 04 25 28 00 00 00 48 89 45 d0 48 8b 47 70 4c 8b a0 d0 06 00 00 48 8b 88 d8 06 00 00 <41> 8b 5c 24 1c 48 89 4d b0 48 89 d8 48 83 c3 20 4d 85 d2 75 31 4c > > >> [ 17.868958] RSP: 0018:ffff9da500a9fde0 EFLAGS: 00010282 > > >> [ 17.868959] RAX: ffff917d03dc4000 RBX: 0000000000000000 RCX: 0000000000000010 > > >> [ 17.868960] RDX: 0000000000001000 RSI: ffff917c99b19460 RDI: ffff917c99b19438 > > >> [ 17.868961] RBP: ffff9da500a9fe38 R08: ffffbda4ffa33fc0 R09: ffff917cbfeae4c0 > > >> [ 17.868962] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000010 > > >> [ 17.868963] R13: ffff917c99b19438 R14: ffff917c99b19460 R15: ffff917c99b19470 > > >> [ 17.868964] FS: 00007f9d80988b00(0000) GS:ffff917d07400000(0000) knlGS:0000000000000000 > > >> [ 17.868965] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > >> [ 17.868966] CR2: 000000000000002c CR3: 0000000219b12004 CR4: 00000000003606f0 > > > > > > It is possible but initially feels a bit weird: > > > > > > - sizeof(TCG_SPECID_SIG)) || count > efispecid->num_algs) { > > > + sizeof(TCG_SPECID_SIG)) || > > > + !efispecid->num_algs || count != efispecid->num_algs) { > > > > > > Assuming that check does not pass because of a more strict constraint, > > > __calc_tpm2_event_size() returns 0. > > > > > > It is wrapped like this in drivers/char/tpm/eventlog/tpm2.c: > > > > > > static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event, > > > struct tcg_pcr_event *event_header) > > > { > > > return __calc_tpm2_event_size(event, event_header, false); > > > } > > > > > > I.e. TPM_MEMUNMAP will not get executed because "do_mapping == false". > > > tpm2_bios_measurements_start() checks for "size == 0" and returns NULL > > > whenever this happens. > > > > > > Are you 100% sure that it is exactly this commit that triggers the bug? > > > > Yes I am 100% sure. The issue happens all the time, and never happens > > if I checkout the previous commit. > > I'm seeing this too on my test Ubuntu laptop. Reverting the patch > fixes it, but there's no data. I do not have yet any reasonable answer to this and my v5.10 PR is running late. Does everyone agree that I should revert the patch? > > Mimi /Jarkko