From patchwork Thu Feb 20 13:59:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 1241444 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netfilter-devel-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=embeddedor.com header.i=@embeddedor.com header.a=rsa-sha256 header.s=default header.b=ShzsgYc+; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48NcCV4YfKz9sPk for ; Fri, 21 Feb 2020 01:19:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727761AbgBTOS7 (ORCPT ); Thu, 20 Feb 2020 09:18:59 -0500 Received: from gateway31.websitewelcome.com ([192.185.143.51]:42657 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726959AbgBTOS7 (ORCPT ); Thu, 20 Feb 2020 09:18:59 -0500 X-Greylist: delayed 1345 seconds by postgrey-1.27 at vger.kernel.org; Thu, 20 Feb 2020 09:18:58 EST Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway31.websitewelcome.com (Postfix) with ESMTP id 733AF677850 for ; Thu, 20 Feb 2020 07:56:33 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 4mJdjq8t18vkB4mJdjmYT2; Thu, 20 Feb 2020 07:56:33 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=zirK+o5UZsICfm9BVZ/hLqxb/7cDvusmuTE5ygvv03w=; b=ShzsgYc+wwKB7dRasTtC5KyS5o x+UEVMoNOP+0nroTV9ZhmB1M3E1G8MvgpHNi0OqRVMy5mwKKs6xZp1qbKI1Fq5bE0o05Z33l1HgK8 WzuSuV/v/RINM0gwEhS1WH5x8/pkdXucc8uE//ZBdHAMLd3itDWGJTmyrVPEq4kABse7+99/JN9Y8 ErKCmxHXtMhbvvX+J+aRnTg3yZPW+rnG7RPEL5X1MK9DP2q66/M49vZmzq5lDXc031wFQX/ycL2dr lP6rVN63Nclmt+wNbTUEI34HooYG5YLIeC/BfPLBM/T/pD91ZfgtaYwumEKSrm4S/V/UqUdkXDqdm kEaMMGFg==; Received: from [201.144.174.47] (port=26793 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j4mJb-003s06-Kd; Thu, 20 Feb 2020 07:56:31 -0600 Date: Thu, 20 Feb 2020 07:59:14 -0600 From: "Gustavo A. R. Silva" To: Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , Roopa Prabhu , Nikolay Aleksandrov , "David S. Miller" , Jakub Kicinski , Alexey Kuznetsov , Hideaki YOSHIFUJI Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-kernel@vger.kernel.org, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH][next] netfilter: Replace zero-length array with flexible-array member Message-ID: <20200220135914.GA14062@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.144.174.47 X-Source-L: No X-Exim-ID: 1j4mJb-003s06-Kd X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.144.174.47]:26793 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 52 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] Lastly, fix checkpatch.pl warning WARNING: __aligned(size) is preferred over __attribute__((aligned(size))) in net/bridge/netfilter/ebtables.c This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- include/linux/netfilter/ipset/ip_set.h | 2 +- include/linux/netfilter/x_tables.h | 8 ++++---- include/linux/netfilter_arp/arp_tables.h | 2 +- include/linux/netfilter_bridge/ebtables.h | 2 +- include/linux/netfilter_ipv4/ip_tables.h | 2 +- include/linux/netfilter_ipv6/ip6_tables.h | 2 +- include/net/netfilter/nf_conntrack_extend.h | 2 +- include/net/netfilter/nf_conntrack_timeout.h | 2 +- include/net/netfilter/nf_tables.h | 6 +++--- include/uapi/linux/netfilter_bridge/ebt_among.h | 2 +- net/bridge/netfilter/ebtables.c | 2 +- net/ipv4/netfilter/arp_tables.c | 4 ++-- net/ipv4/netfilter/ip_tables.c | 4 ++-- net/ipv6/netfilter/ip6_tables.c | 4 ++-- net/netfilter/ipset/ip_set_bitmap_ip.c | 2 +- net/netfilter/ipset/ip_set_bitmap_ipmac.c | 2 +- net/netfilter/ipset/ip_set_bitmap_port.c | 2 +- net/netfilter/ipset/ip_set_hash_gen.h | 4 ++-- net/netfilter/nfnetlink_acct.c | 2 +- net/netfilter/nft_set_pipapo.c | 2 +- net/netfilter/xt_hashlimit.c | 2 +- net/netfilter/xt_recent.c | 4 ++-- 22 files changed, 32 insertions(+), 32 deletions(-) diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h index 908d38dbcb91..155eca0ed68d 100644 --- a/include/linux/netfilter/ipset/ip_set.h +++ b/include/linux/netfilter/ipset/ip_set.h @@ -98,7 +98,7 @@ struct ip_set_counter { struct ip_set_comment_rcu { struct rcu_head rcu; - char str[0]; + char str[]; }; struct ip_set_comment { diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 1b261c51b3a3..5da88451853b 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -264,7 +264,7 @@ struct xt_table_info { unsigned int stacksize; void ***jumpstack; - unsigned char entries[0] __aligned(8); + unsigned char entries[] __aligned(8); }; int xt_register_target(struct xt_target *target); @@ -464,7 +464,7 @@ struct compat_xt_entry_match { } kernel; u_int16_t match_size; } u; - unsigned char data[0]; + unsigned char data[]; }; struct compat_xt_entry_target { @@ -480,7 +480,7 @@ struct compat_xt_entry_target { } kernel; u_int16_t target_size; } u; - unsigned char data[0]; + unsigned char data[]; }; /* FIXME: this works only on 32 bit tasks @@ -494,7 +494,7 @@ struct compat_xt_counters { struct compat_xt_counters_info { char name[XT_TABLE_MAXNAMELEN]; compat_uint_t num_counters; - struct compat_xt_counters counters[0]; + struct compat_xt_counters counters[]; }; struct _compat_xt_align { diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h index e98028f00e47..7d3537c40ec9 100644 --- a/include/linux/netfilter_arp/arp_tables.h +++ b/include/linux/netfilter_arp/arp_tables.h @@ -67,7 +67,7 @@ struct compat_arpt_entry { __u16 next_offset; compat_uint_t comefrom; struct compat_xt_counters counters; - unsigned char elems[0]; + unsigned char elems[]; }; static inline struct xt_entry_target * diff --git a/include/linux/netfilter_bridge/ebtables.h b/include/linux/netfilter_bridge/ebtables.h index 162f59d0d17a..2f5c4e6ecd8a 100644 --- a/include/linux/netfilter_bridge/ebtables.h +++ b/include/linux/netfilter_bridge/ebtables.h @@ -85,7 +85,7 @@ struct ebt_table_info { /* room to maintain the stack used for jumping from and into udc */ struct ebt_chainstack **chainstack; char *entries; - struct ebt_counter counters[0] ____cacheline_aligned; + struct ebt_counter counters[] ____cacheline_aligned; }; struct ebt_table { diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h index e9e1ed74cdf1..b394bd4f68a3 100644 --- a/include/linux/netfilter_ipv4/ip_tables.h +++ b/include/linux/netfilter_ipv4/ip_tables.h @@ -76,7 +76,7 @@ struct compat_ipt_entry { __u16 next_offset; compat_uint_t comefrom; struct compat_xt_counters counters; - unsigned char elems[0]; + unsigned char elems[]; }; /* Helper functions */ diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h index 78ab959c4575..8225f7821a29 100644 --- a/include/linux/netfilter_ipv6/ip6_tables.h +++ b/include/linux/netfilter_ipv6/ip6_tables.h @@ -43,7 +43,7 @@ struct compat_ip6t_entry { __u16 next_offset; compat_uint_t comefrom; struct compat_xt_counters counters; - unsigned char elems[0]; + unsigned char elems[]; }; static inline struct xt_entry_target * diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 5ae5295aa46d..e1e588387103 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -45,7 +45,7 @@ enum nf_ct_ext_id { struct nf_ct_ext { u8 offset[NF_CT_EXT_NUM]; u8 len; - char data[0]; + char data[]; }; static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id) diff --git a/include/net/netfilter/nf_conntrack_timeout.h b/include/net/netfilter/nf_conntrack_timeout.h index 6dd72396f534..659b0ea25b4d 100644 --- a/include/net/netfilter/nf_conntrack_timeout.h +++ b/include/net/netfilter/nf_conntrack_timeout.h @@ -14,7 +14,7 @@ struct nf_ct_timeout { __u16 l3num; const struct nf_conntrack_l4proto *l4proto; - char data[0]; + char data[]; }; struct ctnl_timeout { diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 4170c033d461..abcb4c89b0f9 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -224,7 +224,7 @@ int nft_validate_register_store(const struct nft_ctx *ctx, */ struct nft_userdata { u8 len; - unsigned char data[0]; + unsigned char data[]; }; /** @@ -572,7 +572,7 @@ struct nft_set_ext_tmpl { struct nft_set_ext { u8 genmask; u8 offset[NFT_SET_EXT_NUM]; - char data[0]; + char data[]; }; static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl) @@ -1385,7 +1385,7 @@ struct nft_trans { int msg_type; bool put_net; struct nft_ctx ctx; - char data[0]; + char data[]; }; struct nft_trans_rule { diff --git a/include/uapi/linux/netfilter_bridge/ebt_among.h b/include/uapi/linux/netfilter_bridge/ebt_among.h index 9acf757bc1f7..73b26a280c4f 100644 --- a/include/uapi/linux/netfilter_bridge/ebt_among.h +++ b/include/uapi/linux/netfilter_bridge/ebt_among.h @@ -40,7 +40,7 @@ struct ebt_mac_wormhash_tuple { struct ebt_mac_wormhash { int table[257]; int poolsize; - struct ebt_mac_wormhash_tuple pool[0]; + struct ebt_mac_wormhash_tuple pool[]; }; #define ebt_mac_wormhash_size(x) ((x) ? sizeof(struct ebt_mac_wormhash) \ diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index e1256e03a9a8..78db58c7aec2 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1561,7 +1561,7 @@ struct compat_ebt_entry_mwt { compat_uptr_t ptr; } u; compat_uint_t match_size; - compat_uint_t data[0] __attribute__ ((aligned (__alignof__(struct compat_ebt_replace)))); + compat_uint_t data[] __aligned(__alignof__(struct compat_ebt_replace)); }; /* account for possible padding between match_size and ->data */ diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index f1f78a742b36..b167f4a5b684 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1057,7 +1057,7 @@ struct compat_arpt_replace { u32 underflow[NF_ARP_NUMHOOKS]; u32 num_counters; compat_uptr_t counters; - struct compat_arpt_entry entries[0]; + struct compat_arpt_entry entries[]; }; static inline void compat_release_entry(struct compat_arpt_entry *e) @@ -1383,7 +1383,7 @@ static int compat_copy_entries_to_user(unsigned int total_size, struct compat_arpt_get_entries { char name[XT_TABLE_MAXNAMELEN]; compat_uint_t size; - struct compat_arpt_entry entrytable[0]; + struct compat_arpt_entry entrytable[]; }; static int compat_get_entries(struct net *net, diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 10b91ebdf213..c2670eaa74e6 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1211,7 +1211,7 @@ struct compat_ipt_replace { u32 underflow[NF_INET_NUMHOOKS]; u32 num_counters; compat_uptr_t counters; /* struct xt_counters * */ - struct compat_ipt_entry entries[0]; + struct compat_ipt_entry entries[]; }; static int @@ -1562,7 +1562,7 @@ compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, struct compat_ipt_get_entries { char name[XT_TABLE_MAXNAMELEN]; compat_uint_t size; - struct compat_ipt_entry entrytable[0]; + struct compat_ipt_entry entrytable[]; }; static int diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index c973ace208c5..e27393498ecb 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1227,7 +1227,7 @@ struct compat_ip6t_replace { u32 underflow[NF_INET_NUMHOOKS]; u32 num_counters; compat_uptr_t counters; /* struct xt_counters * */ - struct compat_ip6t_entry entries[0]; + struct compat_ip6t_entry entries[]; }; static int @@ -1571,7 +1571,7 @@ compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, struct compat_ip6t_get_entries { char name[XT_TABLE_MAXNAMELEN]; compat_uint_t size; - struct compat_ip6t_entry entrytable[0]; + struct compat_ip6t_entry entrytable[]; }; static int diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c index 0a2196f59106..486959f70cf3 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -46,7 +46,7 @@ struct bitmap_ip { u8 netmask; /* subnet netmask */ struct timer_list gc; /* garbage collection */ struct ip_set *set; /* attached to this ip_set */ - unsigned char extensions[0] /* data extensions */ + unsigned char extensions[] /* data extensions */ __aligned(__alignof__(u64)); }; diff --git a/net/netfilter/ipset/ip_set_bitmap_ipmac.c b/net/netfilter/ipset/ip_set_bitmap_ipmac.c index 739e343efaf6..2310a316e0af 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ipmac.c +++ b/net/netfilter/ipset/ip_set_bitmap_ipmac.c @@ -49,7 +49,7 @@ struct bitmap_ipmac { size_t memsize; /* members size */ struct timer_list gc; /* garbage collector */ struct ip_set *set; /* attached to this ip_set */ - unsigned char extensions[0] /* MAC + data extensions */ + unsigned char extensions[] /* MAC + data extensions */ __aligned(__alignof__(u64)); }; diff --git a/net/netfilter/ipset/ip_set_bitmap_port.c b/net/netfilter/ipset/ip_set_bitmap_port.c index b49978dd810d..e56ced66f202 100644 --- a/net/netfilter/ipset/ip_set_bitmap_port.c +++ b/net/netfilter/ipset/ip_set_bitmap_port.c @@ -37,7 +37,7 @@ struct bitmap_port { size_t memsize; /* members size */ struct timer_list gc; /* garbage collection */ struct ip_set *set; /* attached to this ip_set */ - unsigned char extensions[0] /* data extensions */ + unsigned char extensions[] /* data extensions */ __aligned(__alignof__(u64)); }; diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index 7480ce55b5c8..f1edc5b9b4ce 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -68,7 +68,7 @@ struct hbucket { DECLARE_BITMAP(used, AHASH_MAX_TUNED); u8 size; /* size of the array */ u8 pos; /* position of the first free entry */ - unsigned char value[0] /* the array of the values */ + unsigned char value[] /* the array of the values */ __aligned(__alignof__(u64)); }; @@ -77,7 +77,7 @@ struct htable { atomic_t ref; /* References for resizing */ atomic_t uref; /* References for dumping */ u8 htable_bits; /* size of hash table == 2^htable_bits */ - struct hbucket __rcu *bucket[0]; /* hashtable buckets */ + struct hbucket __rcu *bucket[]; /* hashtable buckets */ }; #define hbucket(h, i) ((h)->bucket[i]) diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c index 2481470dec36..5827117f2635 100644 --- a/net/netfilter/nfnetlink_acct.c +++ b/net/netfilter/nfnetlink_acct.c @@ -33,7 +33,7 @@ struct nf_acct { refcount_t refcnt; char name[NFACCT_NAME_MAX]; struct rcu_head rcu_head; - char data[0]; + char data[]; }; struct nfacct_filter { diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c index feac8553f6d9..141cea0c5da2 100644 --- a/net/netfilter/nft_set_pipapo.c +++ b/net/netfilter/nft_set_pipapo.c @@ -433,7 +433,7 @@ struct nft_pipapo_match { unsigned long * __percpu *scratch; size_t bsize_max; struct rcu_head rcu; - struct nft_pipapo_field f[0]; + struct nft_pipapo_field f[]; }; /* Current working bitmap index, toggled between field matches */ diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 7a2c4b8408c4..c687509d882e 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -132,7 +132,7 @@ struct xt_hashlimit_htable { const char *name; struct net *net; - struct hlist_head hash[0]; /* hashtable itself */ + struct hlist_head hash[]; /* hashtable itself */ }; static int diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index 0a9708004e20..6e6bc5b91199 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -71,7 +71,7 @@ struct recent_entry { u_int8_t ttl; u_int8_t index; u_int16_t nstamps; - unsigned long stamps[0]; + unsigned long stamps[]; }; struct recent_table { @@ -82,7 +82,7 @@ struct recent_table { unsigned int entries; u8 nstamps_max_mask; struct list_head lru_list; - struct list_head iphash[0]; + struct list_head iphash[]; }; struct recent_net {