From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934927AbcKNRzv (ORCPT ); Mon, 14 Nov 2016 12:55:51 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50728 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754149AbcKNRzm (ORCPT ); Mon, 14 Nov 2016 12:55:42 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, Kees Cook , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 5/7] lkdtm: Add tests for struct list corruption Date: Mon, 14 Nov 2016 09:55:31 -0800 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20161114175500.GA21637@linux.vnet.ibm.com> References: <20161114175500.GA21637@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16111417-0012-0000-0000-000011240243 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006077; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000189; SDB=6.00780621; UDB=6.00376448; IPR=6.00558123; BA=6.00004878; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013322; XFM=3.00000011; UTC=2016-11-14 17:55:39 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16111417-0013-0000-0000-0000472A6487 Message-Id: <1479146133-23058-5-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-11-14_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1611140360 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kees Cook When building under CONFIG_DEBUG_LIST, list addition and removal will be sanity-checked. This validates that the check is working as expected by setting up classic corruption attacks against list manipulations, available with the new lkdtm tests CORRUPT_LIST_ADD and CORRUPT_LIST_DEL. Signed-off-by: Kees Cook Acked-by: Steven Rostedt Signed-off-by: Paul E. McKenney Acked-by: Rik van Riel --- drivers/misc/lkdtm.h | 2 ++ drivers/misc/lkdtm_bugs.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/misc/lkdtm_core.c | 2 ++ 3 files changed, 72 insertions(+) diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index fdf954c2107f..cfa1039c62e7 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/lkdtm.h @@ -21,6 +21,8 @@ void lkdtm_SPINLOCKUP(void); void lkdtm_HUNG_TASK(void); void lkdtm_ATOMIC_UNDERFLOW(void); void lkdtm_ATOMIC_OVERFLOW(void); +void lkdtm_CORRUPT_LIST_ADD(void); +void lkdtm_CORRUPT_LIST_DEL(void); /* lkdtm_heap.c */ void lkdtm_OVERWRITE_ALLOCATION(void); diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c index 182ae1894b32..f336206d4b1f 100644 --- a/drivers/misc/lkdtm_bugs.c +++ b/drivers/misc/lkdtm_bugs.c @@ -5,8 +5,13 @@ * test source files. */ #include "lkdtm.h" +#include #include +struct lkdtm_list { + struct list_head node; +}; + /* * Make sure our attempts to over run the kernel stack doesn't trigger * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we @@ -146,3 +151,66 @@ void lkdtm_ATOMIC_OVERFLOW(void) pr_info("attempting bad atomic overflow\n"); atomic_inc(&over); } + +void lkdtm_CORRUPT_LIST_ADD(void) +{ + /* + * Initially, an empty list via LIST_HEAD: + * test_head.next = &test_head + * test_head.prev = &test_head + */ + LIST_HEAD(test_head); + struct lkdtm_list good, bad; + void *target[2] = { }; + void *redirection = ⌖ + + pr_info("attempting good list addition\n"); + + /* + * Adding to the list performs these actions: + * test_head.next->prev = &good.node + * good.node.next = test_head.next + * good.node.prev = test_head + * test_head.next = good.node + */ + list_add(&good.node, &test_head); + + pr_info("attempting corrupted list addition\n"); + /* + * In simulating this "write what where" primitive, the "what" is + * the address of &bad.node, and the "where" is the address held + * by "redirection". + */ + test_head.next = redirection; + list_add(&bad.node, &test_head); + + if (target[0] == NULL && target[1] == NULL) + pr_err("Overwrite did not happen, but no BUG?!\n"); + else + pr_err("list_add() corruption not detected!\n"); +} + +void lkdtm_CORRUPT_LIST_DEL(void) +{ + LIST_HEAD(test_head); + struct lkdtm_list item; + void *target[2] = { }; + void *redirection = ⌖ + + list_add(&item.node, &test_head); + + pr_info("attempting good list removal\n"); + list_del(&item.node); + + pr_info("attempting corrupted list removal\n"); + list_add(&item.node, &test_head); + + /* As with the list_add() test above, this corrupts "next". */ + item.node.next = redirection; + list_del(&item.node); + + if (target[0] == NULL && target[1] == NULL) + pr_err("Overwrite did not happen, but no BUG?!\n"); + else + pr_err("list_del() corruption not detected!\n"); +} diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index f9154b8d67f6..7eeb71a75549 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -197,6 +197,8 @@ struct crashtype crashtypes[] = { CRASHTYPE(EXCEPTION), CRASHTYPE(LOOP), CRASHTYPE(OVERFLOW), + CRASHTYPE(CORRUPT_LIST_ADD), + CRASHTYPE(CORRUPT_LIST_DEL), CRASHTYPE(CORRUPT_STACK), CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE), CRASHTYPE(OVERWRITE_ALLOCATION), -- 2.5.2