From patchwork Fri Jun 12 07:38:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 217806 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 77739C433E1 for ; Fri, 12 Jun 2020 07:38:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5966C207ED for ; Fri, 12 Jun 2020 07:38:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726507AbgFLHiF (ORCPT ); Fri, 12 Jun 2020 03:38:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:55260 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726292AbgFLHiE (ORCPT ); Fri, 12 Jun 2020 03:38:04 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 02A87AC9F; Fri, 12 Jun 2020 07:38:05 +0000 (UTC) From: Jiri Slaby To: johannes.berg@intel.com Cc: linux-kernel@vger.kernel.org, Jiri Slaby , =?utf-8?q?D?= =?utf-8?q?ieter_N=C3=BCtzel?= , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Kalle Valo , "David S. Miller" , Jakub Kicinski , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH] iwl: fix crash in iwl_dbg_tlv_alloc_trigger Date: Fri, 12 Jun 2020 09:38:00 +0200 Message-Id: <20200612073800.27742-1-jslaby@suse.cz> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The tlv passed to iwl_dbg_tlv_alloc_trigger comes from a loaded firmware file. The memory can be marked as read-only as firmware could be shared. In anyway, writing to this memory is not expected. So, iwl_dbg_tlv_alloc_trigger can crash now: BUG: unable to handle page fault for address: ffffae2c01bfa794 PF: supervisor write access in kernel mode PF: error_code(0x0003) - permissions violation PGD 107d51067 P4D 107d51067 PUD 107d52067 PMD 659ad2067 PTE 8000000662298161 CPU: 2 PID: 161 Comm: kworker/2:1 Not tainted 5.7.0-3.gad96a07-default #1 openSUSE Tumbleweed (unreleased) RIP: 0010:iwl_dbg_tlv_alloc_trigger+0x25/0x60 [iwlwifi] Code: eb f2 0f 1f 00 66 66 66 66 90 83 7e 04 33 48 89 f8 44 8b 46 10 48 89 f7 76 40 41 8d 50 ff 83 fa 19 77 23 8b 56 20 85 d2 75 07 46 20 ff ff ff ff 4b 8d 14 40 48 c1 e2 04 48 8d b4 10 00 05 00 RSP: 0018:ffffae2c00417ce8 EFLAGS: 00010246 RAX: ffff8f0522334018 RBX: ffff8f0522334018 RCX: ffffffffc0fc26c0 RDX: 0000000000000000 RSI: ffffae2c01bfa774 RDI: ffffae2c01bfa774 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000001 R10: 0000000000000034 R11: ffffae2c01bfa77c R12: ffff8f0522334230 R13: 0000000001000009 R14: ffff8f0523fdbc00 R15: ffff8f051f395800 FS: 0000000000000000(0000) GS:ffff8f0527c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffae2c01bfa794 CR3: 0000000389eba000 CR4: 00000000000006e0 Call Trace: iwl_dbg_tlv_alloc+0x79/0x120 [iwlwifi] iwl_parse_tlv_firmware.isra.0+0x57d/0x1550 [iwlwifi] iwl_req_fw_callback+0x3f8/0x6a0 [iwlwifi] request_firmware_work_func+0x47/0x90 process_one_work+0x1e3/0x3b0 worker_thread+0x46/0x340 kthread+0x115/0x140 ret_from_fork+0x1f/0x40 As can be seen, write bit is not set in the PTE. Read of trig->occurrences succeeds in iwl_dbg_tlv_alloc_trigger, but trig->occurrences = cpu_to_le32(-1); fails there, obviously. This is likely because we (at SUSE) use compressed firmware and that is marked as RO after decompression (see fw_map_paged_buf). Fix it by creating a temporary buffer in case we need to change the memory. Signed-off-by: Jiri Slaby Reported-by: Dieter Nützel Tested-by: Dieter Nützel Cc: Johannes Berg Cc: Emmanuel Grumbach Cc: Luca Coelho Cc: Intel Linux Wireless Cc: Kalle Valo Cc: "David S. Miller" Cc: Jakub Kicinski Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org --- drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c index 7987a288917b..27116c7d3f4f 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c @@ -271,6 +271,8 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans, { struct iwl_fw_ini_trigger_tlv *trig = (void *)tlv->data; u32 tp = le32_to_cpu(trig->time_point); + struct iwl_ucode_tlv *dup = NULL; + int ret; if (le32_to_cpu(tlv->length) < sizeof(*trig)) return -EINVAL; @@ -283,10 +285,20 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans, return -EINVAL; } - if (!le32_to_cpu(trig->occurrences)) + if (!le32_to_cpu(trig->occurrences)) { + dup = kmemdup(tlv, sizeof(*tlv) + le32_to_cpu(tlv->length), + GFP_KERNEL); + if (!dup) + return -ENOMEM; + trig = (void *)dup->data; trig->occurrences = cpu_to_le32(-1); + tlv = dup; + } + + ret = iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list); + kfree(dup); - return iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list); + return ret; } static int (*dbg_tlv_alloc[])(struct iwl_trans *trans,