From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753971AbeDAWcj (ORCPT ); Sun, 1 Apr 2018 18:32:39 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:41002 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470AbeDAWci (ORCPT ); Sun, 1 Apr 2018 18:32:38 -0400 Date: Sun, 1 Apr 2018 15:32:37 -0700 From: Matthew Wilcox To: "Tobin C. Harding" Cc: linux-kernel@vger.kernel.org, Eric Biggers Subject: [PATCH] list_debug: Print unmangled addresses Message-ID: <20180401223237.GV13332@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox The entire point of printing the pointers in list_debug is to see if there's any useful information in them (eg poison values, ASCII, etc); obscuring them to see if they compare equal makes them much less useful. If an attacker can force this message to be printed, we've already lost. Signed-off-by: Matthew Wilcox diff --git a/lib/list_debug.c b/lib/list_debug.c index a34db8d27667..5d5424b51b74 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -21,13 +21,13 @@ bool __list_add_valid(struct list_head *new, struct list_head *prev, struct list_head *next) { if (CHECK_DATA_CORRUPTION(next->prev != prev, - "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n", + "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n", prev, next->prev, next) || CHECK_DATA_CORRUPTION(prev->next != next, - "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n", + "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n", next, prev->next, prev) || CHECK_DATA_CORRUPTION(new == prev || new == next, - "list_add double add: new=%p, prev=%p, next=%p.\n", + "list_add double add: new=%px, prev=%px, next=%px.\n", new, prev, next)) return false; @@ -43,16 +43,16 @@ bool __list_del_entry_valid(struct list_head *entry) next = entry->next; if (CHECK_DATA_CORRUPTION(next == LIST_POISON1, - "list_del corruption, %p->next is LIST_POISON1 (%p)\n", + "list_del corruption, %px->next is LIST_POISON1 (%px)\n", entry, LIST_POISON1) || CHECK_DATA_CORRUPTION(prev == LIST_POISON2, - "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", + "list_del corruption, %px->prev is LIST_POISON2 (%px)\n", entry, LIST_POISON2) || CHECK_DATA_CORRUPTION(prev->next != entry, - "list_del corruption. prev->next should be %p, but was %p\n", + "list_del corruption. prev->next should be %px, but was %px\n", entry, prev->next) || CHECK_DATA_CORRUPTION(next->prev != entry, - "list_del corruption. next->prev should be %p, but was %p\n", + "list_del corruption. next->prev should be %px, but was %px\n", entry, next->prev)) return false;