From: Pablo Neira Ayuso <pablo@netfilter.org> To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 5/9] netfilter: nf_tables: Align nft_expr private data to 64-bit Date: Wed, 6 Nov 2019 12:12:33 +0100 Message-ID: <20191106111237.3183-6-pablo@netfilter.org> (raw) In-Reply-To: <20191106111237.3183-1-pablo@netfilter.org> From: Lukas Wunner <lukas@wunner.de> Invoking the following commands on a 32-bit architecture with strict alignment requirements (such as an ARMv7-based Raspberry Pi) results in an alignment exception: # nft add table ip test-ip4 # nft add chain ip test-ip4 output { type filter hook output priority 0; } # nft add rule ip test-ip4 output quota 1025 bytes Alignment trap: not handling instruction e1b26f9f at [<7f4473f8>] Unhandled fault: alignment exception (0x001) at 0xb832e824 Internal error: : 1 [#1] PREEMPT SMP ARM Hardware name: BCM2835 [<7f4473fc>] (nft_quota_do_init [nft_quota]) [<7f447448>] (nft_quota_init [nft_quota]) [<7f4260d0>] (nf_tables_newrule [nf_tables]) [<7f4168dc>] (nfnetlink_rcv_batch [nfnetlink]) [<7f416bd0>] (nfnetlink_rcv [nfnetlink]) [<8078b334>] (netlink_unicast) [<8078b664>] (netlink_sendmsg) [<8071b47c>] (sock_sendmsg) [<8071bd18>] (___sys_sendmsg) [<8071ce3c>] (__sys_sendmsg) [<8071ce94>] (sys_sendmsg) The reason is that nft_quota_do_init() calls atomic64_set() on an atomic64_t which is only aligned to 32-bit, not 64-bit, because it succeeds struct nft_expr in memory which only contains a 32-bit pointer. Fix by aligning the nft_expr private data to 64-bit. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- include/net/netfilter/nf_tables.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 001d294edf57..2d0275f13bbf 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -820,7 +820,8 @@ struct nft_expr_ops { */ struct nft_expr { const struct nft_expr_ops *ops; - unsigned char data[]; + unsigned char data[] + __attribute__((aligned(__alignof__(u64)))); }; static inline void *nft_expr_priv(const struct nft_expr *expr) -- 2.11.0
next prev parent reply index Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-06 11:12 [PATCH 0/9] Netfilter fixes for net Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 1/9] netfilter: nf_tables_offload: check for register data length mismatches Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 2/9] netfilter: ipset: Fix an error code in ip_set_sockfn_get() Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 3/9] netfilter: ipset: Copy the right MAC address in hash:ip,mac IPv6 sets Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 4/9] netfilter: ipset: Fix nla_policies to fully support NL_VALIDATE_STRICT Pablo Neira Ayuso 2019-11-06 11:12 ` Pablo Neira Ayuso [this message] 2019-11-06 11:12 ` [PATCH 6/9] netfilter: nf_tables: fix unexpected EOPNOTSUPP error Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 7/9] bridge: ebtables: don't crash when using dnat target in output chains Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 8/9] netfilter: nf_tables: bogus EOPNOTSUPP on basechain update Pablo Neira Ayuso 2019-11-06 11:12 ` [PATCH 9/9] netfilter: nf_tables_offload: skip EBUSY on chain update Pablo Neira Ayuso 2019-11-07 5:17 ` [PATCH 0/9] Netfilter fixes for net David Miller
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