From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49IroDfAg3aG9nmuHGrYyJrTn4VIuQAkZ6UbD83vNq86a0575WC0tmtfJgKOgVC08CPotb6 ARC-Seal: i=1; a=rsa-sha256; t=1522165335; cv=none; d=google.com; s=arc-20160816; b=jFFQl2CABZ6u8fT5PPKx4gtEOEZaJ5wpkRkzKh3LQnY36dZqf7XiuJl4ZWOfJ9bTmD LSKdm1umGt0LoH7ziTTk56b636NtMP56ksXS8liwkJLh8WPQtDLvy8OuNNd22z8gvFyk dbc7hbMDTJZDyacT4IaruZhvhA8D+tx2IzlMuhw8XMOSN6IDLhoeBIy0iG6IFHov1sF9 cv4IV2wuLEvHK8171zQFk3QeZoR2c8u+ut41C22DNni6I4pTGd4Cpv35DUHtpixxJ+u5 WgGH1Y5unpyf6fgL3JVVsD/KhG7Y4e5tl4SCGejfmglg+oZh8ZAKPb5kqablO5G4zCyW rFUA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:references:in-reply-to:message-id:date:subject:cc:to :from:delivered-to:list-id:list-subscribe:list-unsubscribe:list-help :list-post:precedence:mailing-list:arc-authentication-results; bh=Ag1Atgnn0TdpM19/OWk9ZZoQ4A335k5sZgMog3Xy/y0=; b=pvdqx7t9Gi/ZnaVPIY8HV9ONVNWLqEskm6tKngaZypgiwlWCS5OBkiMUPRK2hY20Rh E3giiCfBN2Ydbpvgrf1fxbrXC9gu9daF7zZfw3SltgI7d5ghcR8ptlesxsl1KX/IyjNL ftJ0NsQs19dXciXHnxv/u1VSnWUc5zWNm9XJo6BvPsi305EvpvhLWZV9PKOrTUwM4fU7 6w6XORbRylIpOhNIH1c5Ek0by2RtLuXMKkxN0bsJr9TMlsY5if9wkkdjJY+jgVNw0sPK VgjznpRWq1F+oYFs4+ZG17VfhuZlABG0kEWIde7skj4M/vg3RbImglqFW38oY2vFEXEn bWlQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12771-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12771-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12771-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12771-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: Igor Stoppa To: , , CC: , , , , , , , , Igor Stoppa Subject: [PATCH 5/6] lkdtm: crash on overwriting protected pmalloc var Date: Tue, 27 Mar 2018 18:37:41 +0300 Message-ID: <20180327153742.17328-6-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180327153742.17328-1-igor.stoppa@huawei.com> References: <20180327153742.17328-1-igor.stoppa@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.122.225.51] X-CFilter-Loop: Reflected X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1596106038584194215?= X-GMAIL-MSGID: =?utf-8?q?1596106038584194215?= 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.h | 1 + drivers/misc/lkdtm_core.c | 3 +++ drivers/misc/lkdtm_perms.c | 25 +++++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index 9e513dcfd809..dcda3ae76ceb 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/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_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_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