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2017-10-08netfilter: invoke synchronize_rcu after set the _hook_ to NULLLiping Zhang
[ Upstream commit 3b7dabf029478bb80507a6c4500ca94132a2bc0b ] Otherwise, another CPU may access the invalid pointer. For example: CPU0 CPU1 - rcu_read_lock(); - pfunc = _hook_; _hook_ = NULL; - mod unload - - pfunc(); // invalid, panic - rcu_read_unlock(); So we must call synchronize_rcu() to wait the rcu reader to finish. Also note, in nf_nat_snmp_basic_fini, synchronize_rcu() will be invoked by later nf_conntrack_helper_unregister, but I'm inclined to add a explicit synchronize_rcu after set the nf_nat_snmp_hook to NULL. Depend on such obscure assumptions is not a good idea. Last, in nfnetlink_cttimeout, we use kfree_rcu to free the time object, so in cttimeout_exit, invoking rcu_barrier() is not necessary at all, remove it too. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11netfilter: use fwmark_reflect in nf_send_resetPau Espin Pedrol
[ Upstream commit cc31d43b4154ad5a7d8aa5543255a93b7e89edc2 ] Otherwise, RST packets generated by ipt_REJECT always have mark 0 when the routing is checked later in the same code path. Fixes: e110861f8609 ("net: add a sysctl to reflect the fwmark on replies") Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pau Espin Pedrol <pau.espin@tessares.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-30netfilter: arp_tables: fix invoking 32bit "iptable -P INPUT ACCEPT" failed ↵Hongxu Jia
in 64bit kernel Since 09d9686047db ("netfilter: x_tables: do compat validation via translate_table"), it used compatr structure to assign newinfo structure. In translate_compat_table of ip_tables.c and ip6_tables.c, it used compatr->hook_entry to replace info->hook_entry and compatr->underflow to replace info->underflow, but not do the same replacement in arp_tables.c. It caused invoking 32-bit "arptbale -P INPUT ACCEPT" failed in 64bit kernel. -------------------------------------- root@qemux86-64:~# arptables -P INPUT ACCEPT root@qemux86-64:~# arptables -P INPUT ACCEPT ERROR: Policy for `INPUT' offset 448 != underflow 0 arptables: Incompatible with this kernel -------------------------------------- Fixes: 09d9686047db ("netfilter: x_tables: do compat validation via translate_table") Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-31netfilter: nft_dup: do not use sreg_dev if the user doesn't specify itLiping Zhang
The NFTA_DUP_SREG_DEV attribute is not a must option, so we should use it in routing lookup only when the user specify it. Fixes: d877f07112f1 ("netfilter: nf_tables: add nft_dup expression") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25Merge branch 'master' of ↵Pablo Neira Ayuso
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next Conflicts: net/netfilter/core.c net/netfilter/nf_tables_netdev.c Resolve two conflicts before pull request for David's net-next tree: 1) Between c73c24849011 ("netfilter: nf_tables_netdev: remove redundant ip_hdr assignment") from the net tree and commit ddc8b6027ad0 ("netfilter: introduce nft_set_pktinfo_{ipv4, ipv6}_validate()"). 2) Between e8bffe0cf964 ("net: Add _nf_(un)register_hooks symbols") and Aaron Conole's patches to replace list_head with single linked list. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25netfilter: nf_log: get rid of XT_LOG_* macrosLiping Zhang
nf_log is used by both nftables and iptables, so use XT_LOG_XXX macros here is not appropriate. Replace them with NF_LOG_XXX. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25netfilter: nft_log: complete NFTA_LOG_FLAGS attr supportLiping Zhang
NFTA_LOG_FLAGS attribute is already supported, but the related NF_LOG_XXX flags are not exposed to the userspace. So we cannot explicitly enable log flags to log uid, tcp sequence, ip options and so on, i.e. such rule "nft add rule filter output log uid" is not supported yet. So move NF_LOG_XXX macro definitions to the uapi/../nf_log.h. In order to keep consistent with other modules, change NF_LOG_MASK to refer to all supported log flags. On the other hand, add a new NF_LOG_DEFAULT_MASK to refer to the original default log flags. Finally, if user specify the unsupported log flags or NFTA_LOG_GROUP and NFTA_LOG_FLAGS are set at the same time, report EINVAL to the userspace. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-24netfilter: Remove explicit rcu_read_lock in nf_hook_slowAaron Conole
All of the callers of nf_hook_slow already hold the rcu_read_lock, so this cleanup removes the recursive call. This is just a cleanup, as the locking code gracefully handles this situation. Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-09-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mediatek/mtk_eth_soc.c drivers/net/ethernet/qlogic/qed/qed_dcbx.c drivers/net/phy/Kconfig All conflicts were cases of overlapping commits. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-12netfilter: Add the missed return value check of nft_register_chain_typeGao Feng
There are some codes of netfilter module which did not check the return value of nft_register_chain_type. Add the checks now. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-12netfilter: nf_tables: ensure proper initialization of nft_pktinfo fieldsPablo Neira Ayuso
This patch introduces nft_set_pktinfo_unspec() that ensures proper initialization all of pktinfo fields for non-IP traffic. This is used by the bridge, netdev and arp families. This new function relies on nft_set_pktinfo_proto_unspec() to set a new tprot_set field that indicates if transport protocol information is available. Remain fields are zeroed. The meta expression has been also updated to check to tprot_set in first place given that zero is a valid tprot value. Even a handcrafted packet may come with the IPPROTO_RAW (255) protocol number so we can't rely on this value as tprot unset. Reported-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-07netfilter: gre: Use consistent GRE and PTTP header structure instead of the ↵Gao Feng
ones defined by netfilter There are two existing strutures which defines the GRE and PPTP header. So use these two structures instead of the ones defined by netfilter to keep consitent with other codes. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-07netfilter: gre: Use consistent GRE_* macros instead of ones defined by ↵Gao Feng
netfilter. There are already some GRE_* macros in kernel, so it is unnecessary to define these macros. And remove some useless macros Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-06netfilter: nft_chain_route: re-route before skb is queued to userspaceLiping Zhang
Imagine such situation, user add the following nft rules, and queue the packets to userspace for further check: # ip rule add fwmark 0x0/0x1 lookup eth0 # ip rule add fwmark 0x1/0x1 lookup eth1 # nft add table filter # nft add chain filter output {type route hook output priority 0 \;} # nft add rule filter output mark set 0x1 # nft add rule filter output queue num 0 But after we reinject the skbuff, the packet will be sent via the wrong route, i.e. in this case, the packet will be routed via eth0 table, not eth1 table. Because we skip to do re-route when verdict is NF_QUEUE, even if the mark was changed. Acctually, we should not touch sk_buff if verdict is NF_DROP or NF_STOLEN, and when re-route fails, return NF_DROP with error code. This is consistent with the mangle table in iptables. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-30netfilter: log: Check param to avoid overflow in nf_log_setGao Feng
The nf_log_set is an interface function, so it should do the strict sanity check of parameters. Convert the return value of nf_log_set as int instead of void. When the pf is invalid, return -EOPNOTSUPP. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-30netfilter: log_arp: Use ARPHRD_ETHER instead of literal '1'Gao Feng
There is one macro ARPHRD_ETHER which defines the ethernet proto for ARP, so we could use it instead of the literal number '1'. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-25netfilter: nft_reject: restrict to INPUT/FORWARD/OUTPUTLiping Zhang
After I add the nft rule "nft add rule filter prerouting reject with tcp reset", kernel panic happened on my system: NULL pointer dereference at ... IP: [<ffffffff81b9db2f>] nf_send_reset+0xaf/0x400 Call Trace: [<ffffffff81b9da80>] ? nf_reject_ip_tcphdr_get+0x160/0x160 [<ffffffffa0928061>] nft_reject_ipv4_eval+0x61/0xb0 [nft_reject_ipv4] [<ffffffffa08e836a>] nft_do_chain+0x1fa/0x890 [nf_tables] [<ffffffffa08e8170>] ? __nft_trace_packet+0x170/0x170 [nf_tables] [<ffffffffa06e0900>] ? nf_ct_invert_tuple+0xb0/0xc0 [nf_conntrack] [<ffffffffa07224d4>] ? nf_nat_setup_info+0x5d4/0x650 [nf_nat] [...] Because in the PREROUTING chain, routing information is not exist, then we will dereference the NULL pointer and oops happen. So we restrict reject expression to INPUT, FORWARD and OUTPUT chain. This is consistent with iptables REJECT target. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-13netfilter: remove ip_conntrack* sysctl compat codePablo Neira Ayuso
This backward compatibility has been around for more than ten years, since Yasuyuki Kozakai introduced IPv6 in conntrack. These days, we have alternate /proc/net/nf_conntrack* entries, the ctnetlink interface and the conntrack utility got adopted by many people in the user community according to what I observed on the netfilter user mailing list. So let's get rid of this. Note that nf_conntrack_htable_size and unsigned int nf_conntrack_max do not need to be exported as symbol anymore. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-11netfilter: use_nf_conn_expires helper in more placesFlorian Westphal
... so we don't need to touch all of these places when we get rid of the timer in nf_conn. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-11netfilter: nf_dup4: remove redundant checksum recalculationLiping Zhang
IP header checksum will be recalculated at ip_local_out, so there's no need to calculated it here, remove it. Also update code comments to illustrate it, and delete the misleading comments about checksum recalculation. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-18netfilter: x_tables: speed up jump target validationFlorian Westphal
The dummy ruleset I used to test the original validation change was broken, most rules were unreachable and were not tested by mark_source_chains(). In some cases rulesets that used to load in a few seconds now require several minutes. sample ruleset that shows the behaviour: echo "*filter" for i in $(seq 0 100000);do printf ":chain_%06x - [0:0]\n" $i done for i in $(seq 0 100000);do printf -- "-A INPUT -j chain_%06x\n" $i printf -- "-A INPUT -j chain_%06x\n" $i printf -- "-A INPUT -j chain_%06x\n" $i done echo COMMIT [ pipe result into iptables-restore ] This ruleset will be about 74mbyte in size, with ~500k searches though all 500k[1] rule entries. iptables-restore will take forever (gave up after 10 minutes) Instead of always searching the entire blob for a match, fill an array with the start offsets of every single ipt_entry struct, then do a binary search to check if the jump target is present or not. After this change ruleset restore times get again close to what one gets when reverting 36472341017529e (~3 seconds on my workstation). [1] every user-defined rule gets an implicit RETURN, so we get 300k jumps + 100k userchains + 100k returns -> 500k rule entries Fixes: 36472341017529e ("netfilter: x_tables: validate targets of jumps") Reported-by: Jeff Wu <wujiafu@gmail.com> Tested-by: Jeff Wu <wujiafu@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11netfilter: conntrack: fix race between nf_conntrack proc read and hash resizeLiping Zhang
When we do "cat /proc/net/nf_conntrack", and meanwhile resize the conntrack hash table via /sys/module/nf_conntrack/parameters/hashsize, race will happen, because reader can observe a newly allocated hash but the old size (or vice versa). So oops will happen like follows: BUG: unable to handle kernel NULL pointer dereference at 0000000000000017 IP: [<ffffffffa0418e21>] seq_print_acct+0x11/0x50 [nf_conntrack] Call Trace: [<ffffffffa0412f4e>] ? ct_seq_show+0x14e/0x340 [nf_conntrack] [<ffffffff81261a1c>] seq_read+0x2cc/0x390 [<ffffffff812a8d62>] proc_reg_read+0x42/0x70 [<ffffffff8123bee7>] __vfs_read+0x37/0x130 [<ffffffff81347980>] ? security_file_permission+0xa0/0xc0 [<ffffffff8123cf75>] vfs_read+0x95/0x140 [<ffffffff8123e475>] SyS_read+0x55/0xc0 [<ffffffff817c2572>] entry_SYSCALL_64_fastpath+0x1a/0xa4 It is very easy to reproduce this kernel crash. 1. open one shell and input the following cmds: while : ; do echo $RANDOM > /sys/module/nf_conntrack/parameters/hashsize done 2. open more shells and input the following cmds: while : ; do cat /proc/net/nf_conntrack done 3. just wait a monent, oops will happen soon. The solution in this patch is based on Florian's Commit 5e3c61f98175 ("netfilter: conntrack: fix lookup race during hash resize"). And add a wrapper function nf_conntrack_get_ht to get hash and hsize suggested by Florian Westphal. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-03netfilter: Convert FWINV<[foo]> macros and uses to NF_INVFJoe Perches
netfilter uses multiple FWINV #defines with identical form that hide a specific structure variable and dereference it with a invflags member. $ git grep "#define FWINV" include/linux/netfilter_bridge/ebtables.h:#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg)) net/bridge/netfilter/ebtables.c:#define FWINV2(bool, invflg) ((bool) ^ !!(e->invflags & invflg)) net/ipv4/netfilter/arp_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg))) net/ipv4/netfilter/ip_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg))) net/ipv6/netfilter/ip6_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ip6info->invflags & (invflg))) net/netfilter/xt_tcpudp.c:#define FWINVTCP(bool, invflg) ((bool) ^ !!(tcpinfo->invflags & (invflg))) Consolidate these macros into a single NF_INVF macro. Miscellanea: o Neaten the alignment around these uses o A few lines are > 80 columns for intelligibility Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-01netfilter: x_tables: simplify ip{6}table_mangle_hook()Pablo Neira Ayuso
No need for a special case to handle NF_INET_POST_ROUTING, this is basically the same handling as for prerouting, input, forward. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24netfilter: nf_reject_ipv4: don't send tcp RST if the packet is non-TCPLiping Zhang
In iptables, if the user add a rule to send tcp RST and specify the non-TCP protocol, such as UDP, kernel will reject this request. But in nftables, this validity check only occurs in nft tool, i.e. only in userspace. This means that user can add such a rule like follows via nfnetlink: "nft add rule filter forward ip protocol udp reject with tcp reset" This will generate some confusing tcp RST packets. So we should send tcp RST only when it is TCP packet. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06netfilter: conntrack: use a single expectation table for all namespacesFlorian Westphal
We already include netns address in the hash and compare the netns pointers during lookup, so even if namespaces have overlapping addresses entries will be spread across the expectation table. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06netfilter: conntrack: check netns when walking expect hashFlorian Westphal
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05netfilter: x_tables: get rid of old and inconsistent debuggingPablo Neira Ayuso
The dprintf() and duprintf() functions are enabled at compile time, these days we have better runtime debugging through pr_debug() and static keys. On top of this, this debugging is so old that I don't expect anyone using this anymore, so let's get rid of this. IP_NF_ASSERT() is still left in place, although this needs that NETFILTER_DEBUG is enabled, I think these assertions provide useful context information when reading the code. Note that ARP_NF_ASSERT() has been removed as there is no user of this. Kill also DEBUG_ALLOW_ALL and a couple of pr_error() and pr_debug() spots that are inconsistently placed in the code. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05netfilter: conntrack: use a single hashtable for all namespacesFlorian Westphal
We already include netns address in the hash and compare the netns pointers during lookup, so even if namespaces have overlapping addresses entries will be spread across the table. Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a 64bit system. NAT bysrc and expectation hash is still per namespace, those will changed too soon. Future patch will also make conntrack object slab cache global again. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05netfilter: conntrack: check netns when comparing conntrack objectsFlorian Westphal
Once we place all conntracks in the same hash table we must also compare the netns pointer to skip conntracks that belong to a different namespace. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05netfilter: conntrack: small refactoring of conntrack seq_printfFlorian Westphal
The iteration process is lockless, so we test if the conntrack object is eligible for printing (e.g. is AF_INET) after obtaining the reference count. Once we put all conntracks into same hash table we might see more entries that need to be skipped. So add a helper and first perform the test in a lockless fashion for fast skip. Once we obtain the reference count, just repeat the check. Note that this refactoring also includes a missing check for unconfirmed conntrack entries due to slab rcu object re-usage, so they need to be skipped since they are not part of the listing. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-29netfilter: fix IS_ERR_VALUE usagePablo Neira Ayuso
This is a forward-port of the original patch from Andrzej Hajda, he said: "IS_ERR_VALUE should be used only with unsigned long type. Otherwise it can work incorrectly. To achieve this function xt_percpu_counter_alloc is modified to return unsigned long, and its result is assigned to temporary variable to perform error checking, before assigning to .pcnt field. The patch follows conclusion from discussion on LKML [1][2]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2120927 [2]: http://permalink.gmane.org/gmane.linux.kernel/2150581" Original patch from Andrzej is here: http://patchwork.ozlabs.org/patch/582970/ This patch has clashed with input validation fixes for x_tables. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree, mostly from Florian Westphal to sort out the lack of sufficient validation in x_tables and connlabel preparation patches to add nf_tables support. They are: 1) Ensure we don't go over the ruleset blob boundaries in mark_source_chains(). 2) Validate that target jumps land on an existing xt_entry. This extra sanitization comes with a performance penalty when loading the ruleset. 3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables. 4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables. 5) Make sure the minimal possible target size in x_tables. 6) Similar to #3, add xt_compat_check_entry_offsets() for compat code. 7) Check that standard target size is valid. 8) More sanitization to ensure that the target_offset field is correct. 9) Add xt_check_entry_match() to validate that matches are well-formed. 10-12) Three patch to reduce the number of parameters in translate_compat_table() for {arp,ip,ip6}tables by using a container structure. 13) No need to return value from xt_compat_match_from_user(), so make it void. 14) Consolidate translate_table() so it can be used by compat code too. 15) Remove obsolete check for compat code, so we keep consistent with what was already removed in the native layout code (back in 2007). 16) Get rid of target jump validation from mark_source_chains(), obsoleted by #2. 17) Introduce xt_copy_counters_from_user() to consolidate counter copying, and use it from {arp,ip,ip6}tables. 18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump functions. 19) Move nf_connlabel_match() to xt_connlabel. 20) Skip event notification if connlabel did not change. 21) Update of nf_connlabels_get() to make the upcoming nft connlabel support easier. 23) Remove spinlock to read protocol state field in conntrack. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-13netfilter: x_tables: introduce and use xt_copy_counters_from_userFlorian Westphal
The three variants use same copy&pasted code, condense this into a helper and use that. Make sure info.name is 0-terminated. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: remove obsolete checkFlorian Westphal
Since 'netfilter: x_tables: validate targets of jumps' change we validate that the target aligns exactly with beginning of a rule, so offset test is now redundant. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: remove obsolete overflow check for compat case tooFlorian Westphal
commit 9e67d5a739327c44885adebb4f3a538050be73e4 ("[NETFILTER]: x_tables: remove obsolete overflow check") left the compat parts alone, but we can kill it there as well. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: do compat validation via translate_tableFlorian Westphal
This looks like refactoring, but its also a bug fix. Problem is that the compat path (32bit iptables, 64bit kernel) lacks a few sanity tests that are done in the normal path. For example, we do not check for underflows and the base chain policies. While its possible to also add such checks to the compat path, its more copy&pastry, for instance we cannot reuse check_underflow() helper as e->target_offset differs in the compat case. Other problem is that it makes auditing for validation errors harder; two places need to be checked and kept in sync. At a high level 32 bit compat works like this: 1- initial pass over blob: validate match/entry offsets, bounds checking lookup all matches and targets do bookkeeping wrt. size delta of 32/64bit structures assign match/target.u.kernel pointer (points at kernel implementation, needed to access ->compatsize etc.) 2- allocate memory according to the total bookkeeping size to contain the translated ruleset 3- second pass over original blob: for each entry, copy the 32bit representation to the newly allocated memory. This also does any special match translations (e.g. adjust 32bit to 64bit longs, etc). 4- check if ruleset is free of loops (chase all jumps) 5-first pass over translated blob: call the checkentry function of all matches and targets. The alternative implemented by this patch is to drop steps 3&4 from the compat process, the translation is changed into an intermediate step rather than a full 1:1 translate_table replacement. In the 2nd pass (step #3), change the 64bit ruleset back to a kernel representation, i.e. put() the kernel pointer and restore ->u.user.name . This gets us a 64bit ruleset that is in the format generated by a 64bit iptables userspace -- we can then use translate_table() to get the 'native' sanity checks. This has two drawbacks: 1. we re-validate all the match and target entry structure sizes even though compat translation is supposed to never generate bogus offsets. 2. we put and then re-lookup each match and target. THe upside is that we get all sanity tests and ruleset validations provided by the normal path and can remove some duplicated compat code. iptables-restore time of autogenerated ruleset with 300k chains of form -A CHAIN0001 -m limit --limit 1/s -j CHAIN0002 -A CHAIN0002 -m limit --limit 1/s -j CHAIN0003 shows no noticeable differences in restore times: old: 0m30.796s new: 0m31.521s 64bit: 0m25.674s Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: xt_compat_match_from_user doesn't need a retvalFlorian Westphal
Always returned 0. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: arp_tables: simplify translate_compat_table argsFlorian Westphal
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: ip_tables: simplify translate_compat_table argsFlorian Westphal
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: check for bogus target offsetFlorian Westphal
We're currently asserting that targetoff + targetsize <= nextoff. Extend it to also check that targetoff is >= sizeof(xt_entry). Since this is generic code, add an argument pointing to the start of the match/target, we can then derive the base structure size from the delta. We also need the e->elems pointer in a followup change to validate matches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: add compat version of xt_check_entry_offsetsFlorian Westphal
32bit rulesets have different layout and alignment requirements, so once more integrity checks get added to xt_check_entry_offsets it will reject well-formed 32bit rulesets. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: kill check_entry helperFlorian Westphal
Once we add more sanity testing to xt_check_entry_offsets it becomes relvant if we're expecting a 32bit 'config_compat' blob or a normal one. Since we already have a lot of similar-named functions (check_entry, compat_check_entry, find_and_check_entry, etc.) and the current incarnation is short just fold its contents into the callers. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: add and use xt_check_entry_offsetsFlorian Westphal
Currently arp/ip and ip6tables each implement a short helper to check that the target offset is large enough to hold one xt_entry_target struct and that t->u.target_size fits within the current rule. Unfortunately these checks are not sufficient. To avoid adding new tests to all of ip/ip6/arptables move the current checks into a helper, then extend this helper in followup patches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: validate targets of jumpsFlorian Westphal
When we see a jump also check that the offset gets us to beginning of a rule (an ipt_entry). The extra overhead is negible, even with absurd cases. 300k custom rules, 300k jumps to 'next' user chain: [ plus one jump from INPUT to first userchain ]: Before: real 0m24.874s user 0m7.532s sys 0m16.076s After: real 0m27.464s user 0m7.436s sys 0m18.840s Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-13netfilter: x_tables: don't move to non-existent next ruleFlorian Westphal
Ben Hawkes says: In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it is possible for a user-supplied ipt_entry structure to have a large next_offset field. This field is not bounds checked prior to writing a counter value at the supplied offset. Base chains enforce absolute verdict. User defined chains are supposed to end with an unconditional return, xtables userspace adds them automatically. But if such return is missing we will move to non-existent next rule. Reported-by: Ben Hawkes <hawkes@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-07netfilter: arp_tables: register table in initnsFlorian Westphal
arptables is broken since we didn't register the table anymore -- even 'arptables -L' fails. Fixes: b9e69e127397187b ("netfilter: xtables: don't hook tables by default") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28netfilter: ipv4: fix NULL dereferenceLiping Zhang
Commit fa50d974d104 ("ipv4: Namespaceify ip_default_ttl sysctl knob") use sock_net(skb->sk) to get the net namespace, but we can't assume that sk_buff->sk is always exist, so when it is NULL, oops will happen. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Reviewed-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28netfilter: x_tables: enforce nul-terminated table name from getsockopt ↵Pablo Neira Ayuso
GET_ENTRIES Make sure the table names via getsockopt GET_ENTRIES is nul-terminated in ebtables and all the x_tables variants and their respective compat code. Uncovered by KASAN. Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>