From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926AbeCFSME (ORCPT ); Tue, 6 Mar 2018 13:12:04 -0500 Received: from tartarus.angband.pl ([89.206.35.136]:54352 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070AbeCFSMC (ORCPT ); Tue, 6 Mar 2018 13:12:02 -0500 From: Adam Borowski To: Petr Mladek , Rasmus Villemoes , Andy Shevchenko , "Tobin C . Harding" , Joe Perches , linux-kernel@vger.kernel.org, Andrew Morton , Michal Hocko Cc: Adam Borowski Date: Tue, 6 Mar 2018 19:11:22 +0100 Message-Id: <20180306181122.11449-2-kilobyte@angband.pl> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180306181122.11449-1-kilobyte@angband.pl> References: <20180306092513.ibodfsnv4xrxdlub@pathway.suse.cz> <20180306181122.11449-1-kilobyte@angband.pl> X-SA-Exim-Connect-IP: 2a02:a312:c201:ce80::6 X-SA-Exim-Mail-From: kilobyte@angband.pl Subject: [PATCH 2/2] vsprintf: don't dereference pointers to the first or last page X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on tartarus.angband.pl) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As old code to avoid so is inconsistent, let's unify it within a single macro. Signed-off-by: Adam Borowski --- lib/vsprintf.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 1c2c3cc5a321..4914dac03f0a 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -47,6 +47,8 @@ #include #include "kstrtox.h" +#define IS_BAD_PTR(x) ((unsigned long)(x) >= (unsigned long)-PAGE_SIZE \ + || (unsigned long)(x) < PAGE_SIZE) #define BAD_PTR_STRING(x) (!(x) ? "(null)" : IS_ERR(x) ? "(err)" : "(invalid)") /** @@ -589,7 +591,7 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec) int len = 0; size_t lim = spec.precision; - if ((unsigned long)s < PAGE_SIZE) + if (IS_BAD_PTR(s)) s = BAD_PTR_STRING(s); while (lim--) { @@ -1583,7 +1585,7 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, if (!IS_ENABLED(CONFIG_OF)) return string(buf, end, "(!OF)", spec); - if ((unsigned long)dn < PAGE_SIZE) + if (IS_BAD_PTR(dn)) return string(buf, end, BAD_PTR_STRING(dn), spec); /* simple case without anything any more format specifiers */ @@ -1851,7 +1853,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, { const int default_width = 2 * sizeof(void *); - if (!ptr && *fmt != 'K' && *fmt != 'x') { + if (IS_BAD_PTR(ptr) && *fmt != 'K' && *fmt != 'x') { /* * Print (null)/etc with the same width as a pointer so it * makes tabular output look nice. @@ -2575,8 +2577,7 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) const char *save_str = va_arg(args, char *); size_t len; - if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE - || (unsigned long)save_str < PAGE_SIZE) + if (IS_BAD_PTR(save_ptr)) save_str = BAD_PTR_STRING(save_str); len = strlen(save_str) + 1; if (str + len < end) -- 2.16.2