From patchwork Thu Mar 8 03:30:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10265957 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5013B60364 for ; Thu, 8 Mar 2018 03:31:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 40D80296B3 for ; Thu, 8 Mar 2018 03:31:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3532B296DB; Thu, 8 Mar 2018 03:31:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 928DE296B3 for ; Thu, 8 Mar 2018 03:31:55 +0000 (UTC) Received: (qmail 18247 invoked by uid 550); 8 Mar 2018 03:31:44 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 18077 invoked from network); 8 Mar 2018 03:31:41 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=8/JGD5N21/88rNE1JK/d3aTTu7fmmAKPKkK5krfJrBY=; b=Ez7imv8+tnAdHTmg8EPaKdekpvALNIM/3FY3aR4S3mqQuIGnwbYPnOXPGHmARf+n3o ai4MANkPVuy1zebVXD1DUGCUAF8DsAwxOn0+gNEP1pti6zmWp6TzwDMQPQzqZdbZd3kT rrQ5fRbb7kI7i7CnRps1L0mV4n2nqfWsDDUVg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=8/JGD5N21/88rNE1JK/d3aTTu7fmmAKPKkK5krfJrBY=; b=HKr13sH2vvpAPy1Be9YwQ+lDN1tSAEjWWs621b4y0uYFXVAxofMNp9UyvybSdt9zlU pQl5wxSHCHybXtL/yn6M51Srt2IiJTS2LIvJ5HolpWx/eXRYbSfUd4rKFq+frB+LCBB3 M7Dh/XPQWYCK7w8+alzXVDiqVitW6zepLwoP6u1FKilQ8sbRfGUDbZ5TEL8zVNGS5fW+ MzNcaTWjOfw6bfT2KGfJf8jSopHYc0XF+uo+fB0+ei117ImngK+1PQMWYbAdBj852VZH 17ZZYDy2m0TO//qhJAA3+H0jDnGAcGDqJIvE+crBnYyhZYojNcQ+1RpOR4lbjx3EEz+y H0Mg== X-Gm-Message-State: APf1xPBgJ23Xyw3CL6+2bN9mvA6i1n240nczWwJSyzcqBKsNoZ8f4mBI WyNtuC7YEOSP18ykcwV5IYvYWg== X-Google-Smtp-Source: AG47ELsd50fMt4ForF+S2T3JnilWN9WZcInmOWVINQ7B1aCagVH8QTgFrdjVDeLXnp9rsuUQizbogg== X-Received: by 2002:a17:902:56c:: with SMTP id 99-v6mr22461469plf.53.1520479890167; Wed, 07 Mar 2018 19:31:30 -0800 (PST) From: Kees Cook To: Andrew Morton Cc: Kees Cook , linux-kernel@vger.kernel.org, corbet@lwn.net, gustavo@embeddedor.com, rostedt@goodmis.org, Chris Mason , Josef Bacik , David Sterba , "David S. Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Masahiro Yamada , Borislav Petkov , Josh Poimboeuf , Randy Dunlap , Ian Abbott , "Tobin C. Harding" , Sergey Senozhatsky , Petr Mladek , Andy Shevchenko , Pantelis Antoniou , linux-btrfs@vger.kernel.org, netdev@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 2/3] net: Remove accidental VLAs from proc buffers Date: Wed, 7 Mar 2018 19:30:46 -0800 Message-Id: <1520479847-39174-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1520479847-39174-1-git-send-email-keescook@chromium.org> References: <1520479847-39174-1-git-send-email-keescook@chromium.org> X-Virus-Scanned: ClamAV using ClamSMTP In the quest to remove all stack VLAs from the kernel[1], this refactors the stack array size calculation to avoid using max(), which makes the compiler think the size isn't fixed. [1] https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kees Cook --- net/ipv4/proc.c | 10 ++++------ net/ipv6/proc.c | 10 ++++------ 2 files changed, 8 insertions(+), 12 deletions(-) diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index dc5edc8f7564..c23c43803435 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -46,8 +46,6 @@ #include #include -#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX) - /* * Report socket allocation statistics [mea@utu.fi] */ @@ -400,11 +398,11 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void *v) static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v) { - unsigned long buff[TCPUDP_MIB_MAX]; + unsigned long buff[SIMPLE_MAX(UDP_MIB_MAX, TCP_MIB_MAX)]; struct net *net = seq->private; int i; - memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + memset(buff, 0, sizeof(buff)); seq_puts(seq, "\nTcp:"); for (i = 0; snmp4_tcp_list[i].name; i++) @@ -421,7 +419,7 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v) seq_printf(seq, " %lu", buff[i]); } - memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + memset(buff, 0, sizeof(buff)); snmp_get_cpu_field_batch(buff, snmp4_udp_list, net->mib.udp_statistics); @@ -432,7 +430,7 @@ static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v) for (i = 0; snmp4_udp_list[i].name; i++) seq_printf(seq, " %lu", buff[i]); - memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long)); + memset(buff, 0, sizeof(buff)); /* the UDP and UDP-Lite MIBs are the same */ seq_puts(seq, "\nUdpLite:"); diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c index b67814242f78..5b0874c26802 100644 --- a/net/ipv6/proc.c +++ b/net/ipv6/proc.c @@ -30,10 +30,8 @@ #include #include -#define MAX4(a, b, c, d) \ - max_t(u32, max_t(u32, a, b), max_t(u32, c, d)) -#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \ - IPSTATS_MIB_MAX, ICMP_MIB_MAX) +#define SNMP_MIB_MAX SIMPLE_MAX(SIMPLE_MAX(UDP_MIB_MAX, TCP_MIB_MAX), \ + SIMPLE_MAX(IPSTATS_MIB_MAX, ICMP_MIB_MAX)) static int sockstat6_seq_show(struct seq_file *seq, void *v) { @@ -199,7 +197,7 @@ static void snmp6_seq_show_item(struct seq_file *seq, void __percpu *pcpumib, int i; if (pcpumib) { - memset(buff, 0, sizeof(unsigned long) * SNMP_MIB_MAX); + memset(buff, 0, sizeof(buff)); snmp_get_cpu_field_batch(buff, itemlist, pcpumib); for (i = 0; itemlist[i].name; i++) @@ -218,7 +216,7 @@ static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib, u64 buff64[SNMP_MIB_MAX]; int i; - memset(buff64, 0, sizeof(u64) * SNMP_MIB_MAX); + memset(buff64, 0, sizeof(buff64)); snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff); for (i = 0; itemlist[i].name; i++)