From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4++msM/6AW6h+WNEZaS7IWTZPSsdxRXaMIdF3gXJ/QBFiAWAl+LcocciciFWZl7w1NPskBk ARC-Seal: i=1; a=rsa-sha256; t=1523627056; cv=none; d=google.com; s=arc-20160816; b=gR+eplEB9O9mci57npkzyy+d/3HCBquhGtzlMJ3rLZChwCahgtxMoVRsjwOY9X7jZI 62Twz/NXksAbbgJQNniQwmNnF2bcMIsGpKeQzpZlpccK2dUO9uxOtCEZBuabOkYER0SB Tp9M49TpV3nPLi5vc4w3UbZaLUy74/8rRc1FhPFIpSj6NJJI4XbNmRoOff/vZC8UWpak qJ5PxWtW66v32nSbQkk9Bb0lYQksV3P1laAc7CNylrfV8VapC862Z4pRsyVzMIGsD8g3 5uVnDkGviIynJoeVSNOXr5bm4Yn286+v/In8HnbM4S3HZ5ONdRpGoPmlSpMMowY/s169 oC8g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=07XywjeaHFrDXVbl8LnLF2bNdgKv2lnLYdnvTw1+COw=; b=o900k9DENKMbOXR8jOloVJovW0+1KM7a/fLmgc5Ugkacz+HsmbPive+vLeAriCXbbx f4q6uNhOHBsU4akJkNykVqe23oXZ1wxSyzVdxsi/icLk377Vxt4phF0M0a9le7YOc548 WSfzL7s2rSY0yXdXgOxr2cheQgX9Qxpv/wCxtEQZ9U67ddhxIOkV+JyIdGFw/jH5iwfm mqlQm2Qn0gHv5O8wpYu+52YVWupz8Ialdu6ZL2vpvVg3QCKwwT0hCpOWoi7PQHMYpAJK GeAq9dDymoEMI1VNUZu9CDEmsClxz+XiLhsbHKkftR0QvPG/xCjQ+PkxDMUS+sqPzgof ppJw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=BP9R5XlF; spf=pass (google.com: domain of kernel-hardening-return-12991-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12991-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=BP9R5XlF; spf=pass (google.com: domain of kernel-hardening-return-12991-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12991-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: willy@infradead.org, keescook@chromium.org, mhocko@kernel.org, corbet@lwn.net Cc: david@fromorbit.com, rppt@linux.vnet.ibm.com, labbott@redhat.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Igor Stoppa Subject: [PATCH 6/6] lkdtm: crash on overwriting protected pmalloc var Date: Fri, 13 Apr 2018 17:41:31 +0400 Message-Id: <20180413134131.4651-7-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180413134131.4651-1-igor.stoppa@huawei.com> References: <20180413134131.4651-1-igor.stoppa@huawei.com> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597638764671049586?= X-GMAIL-MSGID: =?utf-8?q?1597638764671049586?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Verify that pmalloc read-only protection is in place: trying to overwrite a protected variable will crash the kernel. Signed-off-by: Igor Stoppa --- drivers/misc/lkdtm/core.c | 3 +++ drivers/misc/lkdtm/lkdtm.h | 1 + drivers/misc/lkdtm/perms.c | 25 +++++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 2154d1bfd18b..c9fd42bda6ee 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -155,6 +155,9 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(ACCESS_USERSPACE), CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), +#ifdef CONFIG_PROTECTABLE_MEMORY + CRASHTYPE(WRITE_RO_PMALLOC), +#endif CRASHTYPE(WRITE_KERN), CRASHTYPE(REFCOUNT_INC_OVERFLOW), CRASHTYPE(REFCOUNT_ADD_OVERFLOW), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 9e513dcfd809..dcda3ae76ceb 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -38,6 +38,7 @@ void lkdtm_READ_BUDDY_AFTER_FREE(void); void __init lkdtm_perms_init(void); void lkdtm_WRITE_RO(void); void lkdtm_WRITE_RO_AFTER_INIT(void); +void lkdtm_WRITE_RO_PMALLOC(void); void lkdtm_WRITE_KERN(void); void lkdtm_EXEC_DATA(void); void lkdtm_EXEC_STACK(void); diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 53b85c9d16b8..4660ff0bfa44 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -9,6 +9,7 @@ #include #include #include +#include #include /* Whether or not to fill the target memory area with do_nothing(). */ @@ -104,6 +105,30 @@ void lkdtm_WRITE_RO_AFTER_INIT(void) *ptr ^= 0xabcd1234; } +#ifdef CONFIG_PROTECTABLE_MEMORY +void lkdtm_WRITE_RO_PMALLOC(void) +{ + struct pmalloc_pool *pool; + int *i; + + pool = pmalloc_create_pool(); + if (WARN(!pool, "Failed preparing pool for pmalloc test.")) + return; + + i = (int *)pmalloc(pool, sizeof(int)); + if (WARN(!i, "Failed allocating memory for pmalloc test.")) { + pmalloc_destroy_pool(pool); + return; + } + + *i = INT_MAX; + pmalloc_protect_pool(pool); + + pr_info("attempting bad pmalloc write at %p\n", i); + *i = 0; +} +#endif + void lkdtm_WRITE_KERN(void) { size_t size; -- 2.14.1