From patchwork Fri Oct 22 22:38:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 12579117 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40A95C4332F for ; Fri, 22 Oct 2021 22:38:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C4D6109E for ; Fri, 22 Oct 2021 22:38:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234486AbhJVWky (ORCPT ); Fri, 22 Oct 2021 18:40:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234465AbhJVWkx (ORCPT ); Fri, 22 Oct 2021 18:40:53 -0400 Received: from mail-pg1-x533.google.com (mail-pg1-x533.google.com [IPv6:2607:f8b0:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AE42C061220 for ; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) Received: by mail-pg1-x533.google.com with SMTP id f5so4533808pgc.12 for ; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=A4v03Dq8rJnp2emUyjLLIYPOR/r+cJwb6i4GsGFOI3E=; b=mxDJiNxec6TVrFZmoJlMDdG2TzWAATb8LuQP2YucauFIPYK2hJ3AN2eDH0KAnLekdJ csndqVPqIG84nt62c5o82Mmns3j1k/0LyTN0Y0NDu/uYpIT6ifwyDKOb5c7g1WVWZFGg 5rLb8PZNKIlQ86pHNP3cnjGLarqKbTzCyXKeY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=A4v03Dq8rJnp2emUyjLLIYPOR/r+cJwb6i4GsGFOI3E=; b=fMrc63sqhlKYL5dn7e/Hb5Gewud9kwjwuj7skLD+4IsfZYSmNLJ5fo+XnmafKs2ybz n48sAABek+d8LyLFsN1iVnKWLXGmnvRDNs0E79sRGYlvf8IXahmGAZN7hfQI8EB84rCt 7GIC6xhRubfxurdWB7sbvy/IzEU+wN3JpvnvtJH2lQH0Qwwo+xcLthcgwu/rwpMKX30/ fgGdXWLpvz67ZSjG04Z4VWfAFkQgxhbYZaQBlRgCS0en0fgG94IFymNM2WKscBoXeEz1 xa82EVCM+VuV36/wmxYjnyPsI2FnUFpsFTdBLWK7Crtqz3cZEseDDD+XGny03eZRRztp uaqA== X-Gm-Message-State: AOAM532WY5iQazV2J/+G/qWukK8g6mmyPYuzZbn1369OSCjVi2jfawFT kble+eic4zO6UTXxLawKvvmMKQ== X-Google-Smtp-Source: ABdhPJylAPHzu6WrwxpDAXOo4JnVlN1LpYv0YLDCaUU1pzLwefU4HRMEpDaVgnhmLyt39ohRrKUlZg== X-Received: by 2002:a63:6a05:: with SMTP id f5mr1888819pgc.97.1634942315011; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id oj5sm8235pjb.45.2021.10.22.15.38.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Oct 2021 15:38:34 -0700 (PDT) From: Kees Cook To: Greg Kroah-Hartman Cc: Kees Cook , Ard Biesheuvel , Arnd Bergmann , Shuah Khan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 1/2] selftests/lkdtm: Add way to repeat a test Date: Fri, 22 Oct 2021 15:38:25 -0700 Message-Id: <20211022223826.330653-2-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211022223826.330653-1-keescook@chromium.org> References: <20211022223826.330653-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1597; h=from:subject; bh=UVZsTcO0+dkUDOoZKZ0wsUf6jiITa/KlLtRjLgC+IcE=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhcz1hnP4vY/kMhAbyukzou7Lmmlyx3ymfw/9MbmKU WEremomJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYXM9YQAKCRCJcvTf3G3AJoauEA CiXWYCjzhG4dZybCOGZwMn97gQLCmmbZHIKleA6A/neFv1N2L47+XWkNDAgiSDozOBaXjzJFKLYjSV jLxyTEkjahF5Xof1SMFbn997fo8Yv8MsgZyhQnflUG/RxyFUKGRGmihYdfSShaETnXBLpTGQC2jGaA aD0UGaP9WeXqOmnQ74/+LaxFxqaGx3LbxsfEqA0bS6HcM82XhoZoizTe+aAkSI7oWrNRphIx1mXGbv d9zM+nmMs8hf6XxBhUAedls/m7ba5WRbJMLWfQN3Iz33l0S0BAFBUZOtvZCbD1Asgn99wgBSI8gTe6 TDiCzMrmvadEm1rqmzaocxQO0Cnk89qJsNTsanHKwnvQKM+V/BvbWJZgQw742lUGKcF/OVsWCrOSSg gP/kOSqO4K2jNYMpaEoJFzKE4JEPjjoX5PqIjbDuWb6W2vPBPtJZTL6E6y6bU3u6PlVEAmcGjJxjUG dwQ3QMReVamNncGr+5ThpNWPH2kww86py4KqRXgUQKjNEr00HLF3RXh0e4SiHWe4vDABl8S7jpMxZn LGLzeQwR7r2mwxluUzCJpbZte578Yofs+Gil1zdtWKRE7IHzje9xs8J7aXXxh1IWRcKqjN971QLFIK f66hYw7vzoreDQqdmQjTzyQ6goj4EBmhePXwSeOVE2XX8SGiBue1HlXnURAg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Some LKDTM tests need to be run more than once (usually to setup and then later trigger). Until now, the only case was the SOFT_LOCKUP test, which wasn't useful to run in the bulk selftests. The coming stack canary checking needs to run twice, so support this with a new test output prefix "repeat". Signed-off-by: Kees Cook --- tools/testing/selftests/lkdtm/run.sh | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index e95e79bd3126..95e904959207 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -56,8 +56,14 @@ if echo "$test" | grep -q '^#' ; then fi # If no expected output given, assume an Oops with back trace is success. +repeat=1 if [ -z "$expect" ]; then expect="call trace:" +else + if echo "$expect" | grep -q '^repeat:' ; then + repeat=$(echo "$expect" | cut -d' ' -f1 | cut -d: -f2) + expect=$(echo "$expect" | cut -d' ' -f2-) + fi fi # Prepare log for report checking @@ -83,7 +89,9 @@ dmesg > "$DMESG" # the signal that killed the subprocess, we must ignore the failure and # continue. However we don't silence stderr since there might be other # useful details reported there in the case of other unexpected conditions. -echo "$test" | cat >"$TRIGGER" || true +for i in $(seq 1 $repeat); do + echo "$test" | cat >"$TRIGGER" || true +done # Record and dump the results dmesg | comm --nocheck-order -13 "$DMESG" - > "$LOG" || true From patchwork Fri Oct 22 22:38:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 12579119 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0024CC433FE for ; Fri, 22 Oct 2021 22:38:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55F366109E for ; Fri, 22 Oct 2021 22:38:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234489AbhJVWkz (ORCPT ); Fri, 22 Oct 2021 18:40:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234467AbhJVWkx (ORCPT ); Fri, 22 Oct 2021 18:40:53 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A64FFC061224 for ; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id w17so3726214plg.9 for ; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=VhP6k2Ptbi7uCRsPURWI/pJVVcmD5lbioz9gtAtZ1ig=; b=Pf8qWPlOj2elRq79FtuDFpwrlId3NjX+NBYrabhdvxWQMtM6CIeJbqJYM6/vtXX1cf ftnv1ge5eVo/dCwXN58kz0flviZ1i7dNtXjo6B+m38UoFWpBdslQOewNvmdW7bgrWDTr 5X/NqfIlMH0USas7A/PSmaZMHPn7uHyxgY9rg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=VhP6k2Ptbi7uCRsPURWI/pJVVcmD5lbioz9gtAtZ1ig=; b=XlH4udFpMYfD18Ip48FG6FuxJeMr/pSqmJnZ6VCIOpxVyJkElgrK7NW3lXUHItZY4a K5pvuwMZNGKM1ldseVL+HnT3288Wz1SGFG+6dLfpvX6Noi/DdedryL16e6CmRL07nXj/ x1LkqZameFBUFU8bqKvmVRZaQpquyzuBLYVjtyNCtLrnf0EbA9yVieNlmMJ2SpaEyQo9 Kqkf9jkIALA+wLwasabjsKXwPCd1TTS2shAVyu4a+ETFBjseGZw8evbK35rOfQ4HdDbI AZ8I3pT4+rIZcN0cU7PR+1b4qEvMJZkNJdMc14gBcXcrIo1Cy2AdECxwTWRwPvcggrA9 JgPg== X-Gm-Message-State: AOAM532wGp19H4Ez/WzTts3bkuD17JZsqnwp7jaoKI+CBckFPueztO5J cJ44ULd3Mhrq7H4ynoifXt0xXw== X-Google-Smtp-Source: ABdhPJxZaYw7iwxMsd6qWzzFw9KMbHqpMeg8bdlw5gtZ24LK8HXzXpBKY+7Hxx/oYRy7fLc26A0R+Q== X-Received: by 2002:a17:902:82c4:b0:13f:fa72:4b4f with SMTP id u4-20020a17090282c400b0013ffa724b4fmr2489653plz.18.1634942315178; Fri, 22 Oct 2021 15:38:35 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id l6sm71827pfc.126.2021.10.22.15.38.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Oct 2021 15:38:34 -0700 (PDT) From: Kees Cook To: Greg Kroah-Hartman Cc: Kees Cook , Ard Biesheuvel , Arnd Bergmann , Shuah Khan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH 2/2] lkdtm/bugs: Check that a per-task stack canary exists Date: Fri, 22 Oct 2021 15:38:26 -0700 Message-Id: <20211022223826.330653-3-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211022223826.330653-1-keescook@chromium.org> References: <20211022223826.330653-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5525; h=from:subject; bh=lFob2SpNOd7JioxJ+tKziNQRUDdHLjyUqAKU0YX5xYw=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhcz1hVQtS3LUL2AUyeIS59y3JAiez/OuPxCzOHRBp IRmdLiaJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYXM9YQAKCRCJcvTf3G3AJonqEA Cmp0FF89pmJoM7uNrr6aQdyv6i6tmr6ZJIntqUq9HrTLYUzzUIr8HVIRuQeY4z/HXshYK+oSOcI7Bu +EFfwvmuEuyRnyprP4PE8d12Qr30B6MoN/ed0rkoq9kEn/OK+RQbbLo7+oArTAgvlYYbC+U+rV+05d 0mxcnlY32VReNXEVDr5cFavsvJ48icYkEfrTLZbgp4xnqZqF7hIQY2/DInokgrufoCrfid3Zj8kKnc y6U+Al4JRSVat3BEL+we5HvF+rudWFW8rwV2pVyiuoNEjD44r20v4V899GtlUB3F5rhggYaQK8ljbd eoCbqy9ihl+zRD9ZSHgjlRulrGFWiSp/oUHZZO/gsgw9UUGO5eB9cEYbwkRCHCa5wJTXsPSpVPg/EF iEmZ3/lAOgUC514G3T2yk77AhUC5qobWfQApsIbNpNWDEQPTpffzJHT6ipWgKlrYuEKK+yhGv6g9E1 A7QKxsMqA8F3ttOZNcSIevp3etMdqwIlyjlRMWxsZb6D3oFgPF5Oz9avUNk1LuqGWWLz02Jyve2l1W fvnEMJ28Vh8CGKkmKj/YjlawvGEzhMDI4/h0a4hlRe/5mMGVKyCSwZvmptLC+kRfMxoB3NDZxSArHR 3UWzbyaRB+sjY50cMekmCzncSJBk7E97KuySQ9Rgqf4hU0MDFi4TKqpQGWNQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Introduce REPORT_STACK_CANARY to check for differing stack canaries between two processes (i.e. that an architecture is correctly implementing per-task stack canaries), using the task_struct canary as the hint to locate in the stack. Requires that one of the processes being tested not be pid 1. Cc: Ard Biesheuvel Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook --- drivers/misc/lkdtm/bugs.c | 77 +++++++++++++++++++++++++ drivers/misc/lkdtm/core.c | 1 + drivers/misc/lkdtm/lkdtm.h | 1 + tools/testing/selftests/lkdtm/config | 1 + tools/testing/selftests/lkdtm/tests.txt | 1 + 5 files changed, 81 insertions(+) diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 41fa558675c4..f21854ac5cc2 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -153,6 +153,83 @@ void lkdtm_REPORT_STACK(void) pr_info("Stack offset: %d\n", (int)(stack_addr - (uintptr_t)&magic)); } +static pid_t stack_canary_pid; +static unsigned long stack_canary; +static unsigned long stack_canary_offset; + +static noinline void __lkdtm_REPORT_STACK_CANARY(void *stack) +{ + int i = 0; + pid_t pid = task_pid_nr(current); + unsigned long *canary = (unsigned long *)stack; + unsigned long current_offset = 0, init_offset = 0; + + /* Do our best to find the canary in a 16 word window ... */ + for (i = 1; i < 16; i++) { + canary = (unsigned long *)stack + i; +#ifdef CONFIG_STACKPROTECTOR + if (*canary == current->stack_canary) + current_offset = i; + if (*canary == init_task.stack_canary) + init_offset = i; +#endif + } + + if (current_offset == 0) { + /* + * If the canary doesn't match what's in the task_struct, + * we're either using a global canary or the stack frame + * layout changed. + */ + if (init_offset != 0) { + pr_err("FAIL: global stack canary found at offset %ld (canary for pid %d matches init_task's)!\n", + init_offset, pid); + } else { + pr_warn("FAIL: did not correctly locate stack canary :(\n"); + pr_expected_config(CONFIG_STACKPROTECTOR); + } + + return; + } else if (init_offset != 0) { + pr_warn("WARNING: found both current and init_task canaries nearby?!\n"); + } + + canary = (unsigned long *)stack + current_offset; + if (stack_canary_pid == 0) { + stack_canary = *canary; + stack_canary_pid = pid; + stack_canary_offset = current_offset; + pr_info("Recorded stack canary for pid %d at offset %ld\n", + stack_canary_pid, stack_canary_offset); + } else if (pid == stack_canary_pid) { + pr_warn("ERROR: saw pid %d again -- please use a new pid\n", pid); + } else { + if (current_offset != stack_canary_offset) { + pr_warn("ERROR: canary offset changed from %ld to %ld!?\n", + stack_canary_offset, current_offset); + return; + } + + if (*canary == stack_canary) { + pr_warn("FAIL: canary identical for pid %d and pid %d at offset %ld!\n", + stack_canary_pid, pid, current_offset); + } else { + pr_info("ok: stack canaries differ between pid %d and pid %d at offset %ld.\n", + stack_canary_pid, pid, current_offset); + /* Reset the test. */ + stack_canary_pid = 0; + } + } +} + +void lkdtm_REPORT_STACK_CANARY(void) +{ + /* Use default char array length that triggers stack protection. */ + char data[8] __aligned(sizeof(void *)) = { }; + + __lkdtm_REPORT_STACK_CANARY((void *)&data); +} + void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void) { static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5}; diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index e99db37e56d5..d4c6cdced37b 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -111,6 +111,7 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(CORRUPT_STACK), CRASHTYPE(CORRUPT_STACK_STRONG), CRASHTYPE(REPORT_STACK), + CRASHTYPE(REPORT_STACK_CANARY), CRASHTYPE(CORRUPT_LIST_ADD), CRASHTYPE(CORRUPT_LIST_DEL), CRASHTYPE(STACK_GUARD_PAGE_LEADING), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index c212a253edde..d6137c70ebbe 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -69,6 +69,7 @@ void lkdtm_EXHAUST_STACK(void); void lkdtm_CORRUPT_STACK(void); void lkdtm_CORRUPT_STACK_STRONG(void); void lkdtm_REPORT_STACK(void); +void lkdtm_REPORT_STACK_CANARY(void); void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void); void lkdtm_SOFTLOCKUP(void); void lkdtm_HARDLOCKUP(void); diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config index 38edea25631b..a26a3fa9e925 100644 --- a/tools/testing/selftests/lkdtm/config +++ b/tools/testing/selftests/lkdtm/config @@ -8,3 +8,4 @@ CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y CONFIG_UBSAN_BOUNDS=y CONFIG_UBSAN_TRAP=y +CONFIG_STACKPROTECTOR_STRONG=y diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt index 09f7bfa383cc..6b36b7f5dcf9 100644 --- a/tools/testing/selftests/lkdtm/tests.txt +++ b/tools/testing/selftests/lkdtm/tests.txt @@ -12,6 +12,7 @@ CORRUPT_LIST_ADD list_add corruption CORRUPT_LIST_DEL list_del corruption STACK_GUARD_PAGE_LEADING STACK_GUARD_PAGE_TRAILING +REPORT_STACK_CANARY repeat:2 ok: stack canaries differ UNSET_SMEP pinned CR4 bits changed: DOUBLE_FAULT CORRUPT_PAC