From 568af6de058cb2b0c5b98d98ffcf37cdc6bc38a7 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sat, 4 Mar 2017 19:53:47 +0100 Subject: netfilter: nf_tables: set pktinfo->thoff at AH header if found Phil Sutter reports that IPv6 AH header matching is broken. From userspace, nft generates bytecode that expects to find the AH header at NFT_PAYLOAD_TRANSPORT_HEADER both for IPv4 and IPv6. However, pktinfo->thoff is set to the inner header after the AH header in IPv6, while in IPv4 pktinfo->thoff points to the AH header indeed. This behaviour is inconsistent. This patch fixes this problem by updating ipv6_find_hdr() to get the IP6_FH_F_AUTH flag so this function stops at the AH header, so both IPv4 and IPv6 pktinfo->thoff point to the AH header. This is also inconsistent when trying to match encapsulated headers: 1) A packet that looks like IPv4 + AH + TCP dport 22 will *not* match. 2) A packet that looks like IPv6 + AH + TCP dport 22 will match. Reported-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables_ipv6.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/net/netfilter') diff --git a/include/net/netfilter/nf_tables_ipv6.h b/include/net/netfilter/nf_tables_ipv6.h index d150b5066201..97983d1c05e4 100644 --- a/include/net/netfilter/nf_tables_ipv6.h +++ b/include/net/netfilter/nf_tables_ipv6.h @@ -9,12 +9,13 @@ nft_set_pktinfo_ipv6(struct nft_pktinfo *pkt, struct sk_buff *skb, const struct nf_hook_state *state) { + unsigned int flags = IP6_FH_F_AUTH; int protohdr, thoff = 0; unsigned short frag_off; nft_set_pktinfo(pkt, skb, state); - protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); + protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags); if (protohdr < 0) { nft_set_pktinfo_proto_unspec(pkt, skb); return; @@ -32,6 +33,7 @@ __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt, const struct nf_hook_state *state) { #if IS_ENABLED(CONFIG_IPV6) + unsigned int flags = IP6_FH_F_AUTH; struct ipv6hdr *ip6h, _ip6h; unsigned int thoff = 0; unsigned short frag_off; @@ -50,7 +52,7 @@ __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt, if (pkt_len + sizeof(*ip6h) > skb->len) return -1; - protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); + protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags); if (protohdr < 0) return -1; -- cgit v1.2.3 From 10596608c4d62cb8c1c2b806debcbd32fe657e71 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Wed, 8 Mar 2017 22:54:18 +0800 Subject: netfilter: nf_tables: fix mismatch in big-endian system Currently, there are two different methods to store an u16 integer to the u32 data register. For example: u32 *dest = ®s->data[priv->dreg]; 1. *dest = 0; *(u16 *) dest = val_u16; 2. *dest = val_u16; For method 1, the u16 value will be stored like this, either in big-endian or little-endian system: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | Value | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+ For method 2, in little-endian system, the u16 value will be the same as listed above. But in big-endian system, the u16 value will be stored like this: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | Value | +-+-+-+-+-+-+-+-+-+-+-+-+ So later we use "memcmp(®s->data[priv->sreg], data, 2);" to do compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong result in big-endian system, as 0~15 bits will always be zero. For the similar reason, when loading an u16 value from the u32 data register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;", the 2nd method will get the wrong value in the big-endian system. So introduce some wrapper functions to store/load an u8 or u16 integer to/from the u32 data register, and use them in the right place. Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/net/netfilter') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 2aa8a9d80fbe..70c5ca0c60b1 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -103,6 +103,35 @@ struct nft_regs { }; }; +/* Store/load an u16 or u8 integer to/from the u32 data register. + * + * Note, when using concatenations, register allocation happens at 32-bit + * level. So for store instruction, pad the rest part with zero to avoid + * garbage values. + */ + +static inline void nft_reg_store16(u32 *dreg, u16 val) +{ + *dreg = 0; + *(u16 *)dreg = val; +} + +static inline void nft_reg_store8(u32 *dreg, u8 val) +{ + *dreg = 0; + *(u8 *)dreg = val; +} + +static inline u16 nft_reg_load16(u32 *sreg) +{ + return *(u16 *)sreg; +} + +static inline u8 nft_reg_load8(u32 *sreg) +{ + return *(u8 *)sreg; +} + static inline void nft_data_copy(u32 *dst, const struct nft_data *src, unsigned int len) { -- cgit v1.2.3 From 170a1fb9c01bc40b7e8fd57a32ac9a0e131ec5b6 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Sat, 11 Mar 2017 00:25:26 -0500 Subject: netfilter: Force fake conntrack entry to be at least 8 bytes aligned Since the nfct and nfctinfo have been combined, the nf_conn structure must be at least 8 bytes aligned, as the 3 LSB bits are used for the nfctinfo. But there's a fake nf_conn structure to denote untracked connections, which is created by a PER_CPU construct. This does not guarantee that it will be 8 bytes aligned and can break the logic in determining the correct nfctinfo. I triggered this on a 32bit machine with the following error: BUG: unable to handle kernel NULL pointer dereference at 00000af4 IP: nf_ct_deliver_cached_events+0x1b/0xfb *pdpt = 0000000031962001 *pde = 0000000000000000 Oops: 0000 [#1] SMP [Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 crc_ccitt ppdev r8169 parport_pc parport OK ] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-test+ #75 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 task: c126ec00 task.stack: c1258000 EIP: nf_ct_deliver_cached_events+0x1b/0xfb EFLAGS: 00010202 CPU: 0 EAX: 0021cd01 EBX: 00000000 ECX: 27b0c767 EDX: 32bcb17a ESI: f34135c0 EDI: f34135c0 EBP: f2debd60 ESP: f2debd3c DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 CR0: 80050033 CR2: 00000af4 CR3: 309a0440 CR4: 001406f0 Call Trace: ? ipv6_skip_exthdr+0xac/0xcb ipv6_confirm+0x10c/0x119 [nf_conntrack_ipv6] nf_hook_slow+0x22/0xc7 nf_hook+0x9a/0xad [ipv6] ? ip6t_do_table+0x356/0x379 [ip6_tables] ? ip6_fragment+0x9e9/0x9e9 [ipv6] ip6_output+0xee/0x107 [ipv6] ? ip6_fragment+0x9e9/0x9e9 [ipv6] dst_output+0x36/0x4d [ipv6] NF_HOOK.constprop.37+0xb2/0xba [ipv6] ? icmp6_dst_alloc+0x2c/0xfd [ipv6] ? local_bh_enable+0x14/0x14 [ipv6] mld_sendpack+0x1c5/0x281 [ipv6] ? mark_held_locks+0x40/0x5c mld_ifc_timer_expire+0x1f6/0x21e [ipv6] call_timer_fn+0x135/0x283 ? detach_if_pending+0x55/0x55 ? mld_dad_timer_expire+0x3e/0x3e [ipv6] __run_timers+0x111/0x14b ? mld_dad_timer_expire+0x3e/0x3e [ipv6] run_timer_softirq+0x1c/0x36 __do_softirq+0x185/0x37c ? test_ti_thread_flag.constprop.19+0xd/0xd do_softirq_own_stack+0x22/0x28 irq_exit+0x5a/0xa4 smp_apic_timer_interrupt+0x2a/0x34 apic_timer_interrupt+0x37/0x3c By using DEFINE/DECLARE_PER_CPU_ALIGNED we can enforce at least 8 byte alignment as all cache line sizes are at least 8 bytes or more. Fixes: a9e419dc7be6 ("netfilter: merge ctinfo into nfct pointer storage area") Signed-off-by: Steven Rostedt (VMware) Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/net/netfilter') diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index f540f9ad2af4..19605878da47 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -244,7 +244,7 @@ extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct, u32 seq); /* Fake conntrack entry for untracked connections */ -DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked); +DECLARE_PER_CPU_ALIGNED(struct nf_conn, nf_conntrack_untracked); static inline struct nf_conn *nf_ct_untracked_get(void) { return raw_cpu_ptr(&nf_conntrack_untracked); -- cgit v1.2.3 From 04166f48d9593af4513ae06c0f966c0cee300a20 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 13 Mar 2017 13:24:03 +0100 Subject: Revert "netfilter: nf_tables: add flush field to struct nft_set_iter" This reverts commit 1f48ff6c5393aa7fe290faf5d633164f105b0aa7. This patch is not required anymore now that we keep a dummy list of set elements in the bitmap set implementation, so revert this before we forget this code has no clients. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/net/netfilter') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 70c5ca0c60b1..0136028652bd 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -232,7 +232,6 @@ struct nft_set_elem { struct nft_set; struct nft_set_iter { u8 genmask; - bool flush; unsigned int count; unsigned int skip; int err; -- cgit v1.2.3