From patchwork Tue Apr 5 07:18:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 558168 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CFCC5C433EF for ; Tue, 5 Apr 2022 08:03:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233282AbiDEIFo (ORCPT ); Tue, 5 Apr 2022 04:05:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235583AbiDEH7w (ORCPT ); Tue, 5 Apr 2022 03:59:52 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59D064130E; Tue, 5 Apr 2022 00:55:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 08309B81B90; Tue, 5 Apr 2022 07:55:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59184C340EE; Tue, 5 Apr 2022 07:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649145344; bh=3GCCv3bTodWDwZEnREnlZNV5Qi+FtPxKKF+qHajrJmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q8fpvp0KVaZub3w0LeycXD7/wfOcW1SOtFa4fJ5US2AwOb0Vsye/nnCcsCijuO9Qo 0dS7m8Y/t5dhh1iPXj8HHs4NZPbf7k9lCEjtfx4QbXbpSaURFyBGL2DZ1XygPKjUGF HLKr4bLC2KAsYB84vEpuFc/GroG/i/O/xBtMnGPk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Petr Mladek , Sasha Levin Subject: [PATCH 5.17 0370/1126] vsprintf: Fix %pK with kptr_restrict == 0 Date: Tue, 5 Apr 2022 09:18:37 +0200 Message-Id: <20220405070418.487239809@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christophe Leroy [ Upstream commit 84842911322fc6a02a03ab9e728a48c691fe3efd ] Although kptr_restrict is set to 0 and the kernel is booted with no_hash_pointers parameter, the content of /proc/vmallocinfo is lacking the real addresses. / # cat /proc/vmallocinfo 0x(ptrval)-0x(ptrval) 8192 load_module+0xc0c/0x2c0c pages=1 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap 0x(ptrval)-0x(ptrval) 12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap ... According to the documentation for /proc/sys/kernel/, %pK is equivalent to %p when kptr_restrict is set to 0. Fixes: 5ead723a20e0 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed") Signed-off-by: Christophe Leroy Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/107476128e59bff11a309b5bf7579a1753a41aca.1645087605.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- .../admin-guide/kernel-parameters.txt | 3 +- lib/vsprintf.c | 36 +++++++++++-------- 2 files changed, 22 insertions(+), 17 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 7123524a86b8..59f881f36779 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3485,8 +3485,7 @@ difficult since unequal pointers can no longer be compared. However, if this command-line option is specified, then all normal pointers will have their true - value printed. Pointers printed via %pK may still be - hashed. This option should only be specified when + value printed. This option should only be specified when debugging the kernel. Please do not use on production kernels. diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 1ff73ac9e820..fbf261bbea95 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -54,6 +54,10 @@ #include #include "kstrtox.h" +/* Disable pointer hashing if requested */ +bool no_hash_pointers __ro_after_init; +EXPORT_SYMBOL_GPL(no_hash_pointers); + static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base) { const char *cp; @@ -849,6 +853,19 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr, return pointer_string(buf, end, (const void *)hashval, spec); } +static char *default_pointer(char *buf, char *end, const void *ptr, + struct printf_spec spec) +{ + /* + * default is to _not_ leak addresses, so hash before printing, + * unless no_hash_pointers is specified on the command line. + */ + if (unlikely(no_hash_pointers)) + return pointer_string(buf, end, ptr, spec); + + return ptr_to_id(buf, end, ptr, spec); +} + int kptr_restrict __read_mostly; static noinline_for_stack @@ -858,7 +875,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr, switch (kptr_restrict) { case 0: /* Handle as %p, hash and do _not_ leak addresses. */ - return ptr_to_id(buf, end, ptr, spec); + return default_pointer(buf, end, ptr, spec); case 1: { const struct cred *cred; @@ -2225,10 +2242,6 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, return widen_string(buf, buf - buf_start, end, spec); } -/* Disable pointer hashing if requested */ -bool no_hash_pointers __ro_after_init; -EXPORT_SYMBOL_GPL(no_hash_pointers); - int __init no_hash_pointers_enable(char *str) { if (no_hash_pointers) @@ -2457,7 +2470,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'e': /* %pe with a non-ERR_PTR gets treated as plain %p */ if (!IS_ERR(ptr)) - break; + return default_pointer(buf, end, ptr, spec); return err_ptr(buf, end, ptr, spec); case 'u': case 'k': @@ -2467,16 +2480,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, default: return error_string(buf, end, "(einval)", spec); } + default: + return default_pointer(buf, end, ptr, spec); } - - /* - * default is to _not_ leak addresses, so hash before printing, - * unless no_hash_pointers is specified on the command line. - */ - if (unlikely(no_hash_pointers)) - return pointer_string(buf, end, ptr, spec); - else - return ptr_to_id(buf, end, ptr, spec); } /*