From patchwork Fri Dec 2 04:45:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 28705 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp648593wrr; Thu, 1 Dec 2022 20:57:01 -0800 (PST) X-Google-Smtp-Source: AA0mqf6dBgT+FRzTycqpv2VYd+DJBfONaDu58iiCPMWAx5713gsi4abPBGLReIIKpxJeDfKnZKtV X-Received: by 2002:a17:906:4997:b0:7ae:ec5c:a99e with SMTP id p23-20020a170906499700b007aeec5ca99emr41307583eju.219.1669957021299; Thu, 01 Dec 2022 20:57:01 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1669957021; cv=none; d=google.com; s=arc-20160816; b=e6xWRmVzMdxYYU1THPuNcshaYrbA+ZaGY3+GMN3Z3RlDGqGYwttEXqXagcCVNAwWOu icJlXM3GUkQYzZWyQNbNKSE1hGkvTVvNdDpCCuoQKrxuRDvhMb6cnoH/8q5WK1tzykNz Ez98KGz9wAFvNHRO7RiJsNxM4qE0jlzb3BMr3w0WyeUEu7fkk9dGpOFAQut4Mh7iADTK LoD3fq3pm3xDU1xerydU0pvs0B/g7MGvD7y8F1aLFCWJMrb/d7ff3l++ePQ7Y+9IzMsZ 8Os8mfr6Kg5wTbr2PtkzGAdBlI4jVtcoNpLz/BgpPfPZbg4C53zQSLQ1xBpRl9LaGrvQ agRw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:message-id:date:subject:cc:to:from:dkim-signature; bh=Q5WMWkDcmv2bNFMSekgeVuol2Bp7i32UWqJdcyJpoYU=; b=CB4KIIp7fBLjsljSyADa16lfPL261YQLtxMjueHpMO11uFYonUPJ148eG514QvAX87 7lDAk40yLAuNxYqoUt3cXOK4PGnD9RP2T7PkwW7iBeDmtWtAAVkNzMaxLYu5bPiUcNju RuVV1mptMlHDH6x1lhdrZ3z+E340CN0e5gIqDVuaz1fcm/dtBsqqtgifpCCaWL3gOATJ ECA+q/rHTjrW/9oe8lwKL5nns+zgkObHoyxdO4bc4wVcW0yeeX9dqUfe5E3raBXD51fB pvpR6LFuGpW92FJRQEuQJLnyA3pHBGAzb870UHW0ILri4h9c4t0ZbHatAY5mM/gJrq8K 7JGQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=mn+IoppK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id b11-20020a056402084b00b0045dc9b4c034si5527287edz.582.2022.12.01.20.56.37; Thu, 01 Dec 2022 20:57:01 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=mn+IoppK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232068AbiLBEqM (ORCPT + 99 others); Thu, 1 Dec 2022 23:46:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231578AbiLBEqJ (ORCPT ); Thu, 1 Dec 2022 23:46:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59AA8D679E; Thu, 1 Dec 2022 20:46:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 070DFB820A9; Fri, 2 Dec 2022 04:46:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C05CC433D7; Fri, 2 Dec 2022 04:46:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669956364; bh=UiL3Tb7gm2PApOES13tLz7BW0HNCgZohBDZDdYDnv8U=; h=From:To:Cc:Subject:Date:From; b=mn+IoppK2cJtLbsEBVYor4VjYEz8274Q3NzRMoaK75dOsjyxAIMQgU+70Nd8qHqsY +EnNTsSDLBYJAfaBPo2X7MfvhxeJF0dEsKTUymSFMtLBfTqGSxXEfNG9Pb2WAyc5kV N6Y8fA2M5HwoSv2ps/kwe1W7SMyANeC5nGk/FLsygm0/bnOFTFCYf56Eg8d78p6RvG 4SIIHtdfZ5H2BJNjtp8rScqGhQQ6kdgZg95UjrsMSCvqedboTIOcEA6j0c9iSLpyqW 6fhMgAVrqKlSp8XD2jmyglAEOER0pp9DVsXb05VTbUTrivOggCpzD1GRtFYlYuY2d2 j01YCVtLo/5EA== From: "Masami Hiramatsu (Google)" To: LKML Cc: bpf@vger.kernel.org, Borislav Petkov , Alexei Starovoitov , Steven Rostedt , Linus Torvalds , Masami Hiramatsu , Andrew Morton , Peter Zijlstra , Kees Cook , Josh Poimboeuf , KP Singh , Mark Rutland , Florent Revest , Greg Kroah-Hartman , Christoph Hellwig , Chris Mason Subject: [PATCH] panic: Taint kernel if fault injection has been used Date: Fri, 2 Dec 2022 13:45:59 +0900 Message-Id: <166995635931.455067.17768077948832448089.stgit@devnote3> X-Mailer: git-send-email 2.39.0.rc0.267.gcb52ba06e7-goog User-Agent: StGit/0.19 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1751076853620181515?= X-GMAIL-MSGID: =?utf-8?q?1751076853620181515?= From: Masami Hiramatsu (Google) Since the function error injection framework in the fault injection subsystem can change the function code flow forcibly, it may cause unexpected behavior (and that is the purpose of this feature) even if it is applied to the ALLOW_ERROR_INJECTION functions. So this feature must be used only for debugging or testing purpose. To identify this in the kernel oops message, add a new taint flag for the fault injection. This taint flag will be set by either function error injection is used or the BPF use the kprobe_override on error injectable functions (identified by ALLOW_ERROR_INJECTION). Link: https://lore.kernel.org/all/20221121104403.1545f9b5@gandalf.local.home/T/#u Signed-off-by: Masami Hiramatsu (Google) --- Documentation/admin-guide/tainted-kernels.rst | 5 +++++ include/linux/panic.h | 3 ++- kernel/fail_function.c | 2 ++ kernel/panic.c | 1 + kernel/trace/bpf_trace.c | 2 ++ 5 files changed, 12 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index 92a8a07f5c43..63d7cd4f6250 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -101,6 +101,7 @@ Bit Log Number Reason that got the kernel tainted 16 _/X 65536 auxiliary taint, defined for and used by distros 17 _/T 131072 kernel was built with the struct randomization plugin 18 _/N 262144 an in-kernel test has been run + 19 _/J 524288 a function-level error has been injected === === ====== ======================================================== Note: The character ``_`` is representing a blank in this table to make reading @@ -182,3 +183,7 @@ More detailed explanation for tainting produce extremely unusual kernel structure layouts (even performance pathological ones), which is important to know when debugging. Set at build time. + + 19) ``J`` if a function-level error has been injected and the code path was + forcibly changed by either function error injection framework or BPF's + function override feature. diff --git a/include/linux/panic.h b/include/linux/panic.h index c7759b3f2045..2b03a02d86be 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -69,7 +69,8 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) #define TAINT_AUX 16 #define TAINT_RANDSTRUCT 17 #define TAINT_TEST 18 -#define TAINT_FLAGS_COUNT 19 +#define TAINT_FAULT_INJECTED 19 +#define TAINT_FLAGS_COUNT 20 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) struct taint_flag { diff --git a/kernel/fail_function.c b/kernel/fail_function.c index a7ccd2930c5f..80a743f14a2c 100644 --- a/kernel/fail_function.c +++ b/kernel/fail_function.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -298,6 +299,7 @@ static ssize_t fei_write(struct file *file, const char __user *buffer, fei_attr_free(attr); goto out; } + add_taint(TAINT_FAULT_INJECTED, LOCKDEP_NOW_UNRELIABLE); fei_debugfs_add_attr(attr); list_add_tail(&attr->list, &fei_attr_list); ret = count; diff --git a/kernel/panic.c b/kernel/panic.c index da323209f583..e396a5fd9bb6 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -426,6 +426,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { [ TAINT_AUX ] = { 'X', ' ', true }, [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, [ TAINT_TEST ] = { 'N', ' ', true }, + [ TAINT_FAULT_INJECTED ] = { 'J', ' ', false }, }; /** diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1ed08967fb97..de0614d9796c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2137,6 +2137,8 @@ int perf_event_attach_bpf_prog(struct perf_event *event, goto unlock; /* set the new array to event->tp_event and set event->prog */ + if (prog->kprobe_override) + add_taint(TAINT_FAULT_INJECTED, LOCKDEP_NOW_UNRELIABLE); event->prog = prog; event->bpf_cookie = bpf_cookie; rcu_assign_pointer(event->tp_event->prog_array, new_array);