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2018-01-31netfilter: nfnetlink_cthelper: Add missing permission checksKevin Cernekee1-0/+10
commit 4b380c42f7d00a395feede754f0bc2292eebe6e5 upstream. The capability check in nfnetlink_rcv() verifies that the caller has CAP_NET_ADMIN in the namespace that "owns" the netlink socket. However, nfnl_cthelper_list is shared by all net namespaces on the system. An unprivileged user can create user and net namespaces in which he holds CAP_NET_ADMIN to bypass the netlink_net_capable() check: $ nfct helper list nfct v1.4.4: netlink error: Operation not permitted $ vpnns -- nfct helper list { .name = ftp, .queuenum = 0, .l3protonum = 2, .l4protonum = 6, .priv_data_len = 24, .status = enabled, }; Add capable() checks in nfnetlink_cthelper, as this is cleaner than trying to generalize the solution. Signed-off-by: Kevin Cernekee <cernekee@chromium.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-25netfilter: nfnl_cthelper: fix a race when walk the nf_ct_helper_hash tableLiping Zhang1-96/+81
[ Upstream commit 83d90219a5df8d950855ce73229a97b63605c317 ] The nf_ct_helper_hash table is protected by nf_ct_helper_mutex, while nfct_helper operation is protected by nfnl_lock(NFNL_SUBSYS_CTHELPER). So it's possible that one CPU is walking the nf_ct_helper_hash for cthelper add/get/del, another cpu is doing nf_conntrack_helpers_unregister at the same time. This is dangrous, and may cause use after free error. Note, delete operation will flush all cthelpers added via nfnetlink, so using rcu to do protect is not easy. Now introduce a dummy list to record all the cthelpers added via nfnetlink, then we can walk the dummy list instead of walking the nf_ct_helper_hash. Also, keep nfnl_cthelper_dump_table unchanged, it may be invoked without nfnl_lock(NFNL_SUBSYS_CTHELPER) held. 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>
2017-12-25netfilter: nfnl_cthelper: Fix memory leakJeffy Chen1-3/+9
[ Upstream commit f83bf8da1135ca635aac8f062cad3f001fcf3a26 ] We have memory leaks of nf_conntrack_helper & expect_policy. Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.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>
2017-12-25netfilter: nfnl_cthelper: fix runtime expectation policy updatesPablo Neira Ayuso1-2/+84
[ Upstream commit 2c422257550f123049552b39f7af6e3428a60f43 ] We only allow runtime updates of expectation policies for timeout and maximum number of expectations, otherwise reject the update. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08netfilter: nfnl_cthelper: fix incorrect helper->expect_class_maxLiping Zhang1-9/+11
[ Upstream commit ae5c682113f9f94cc5e76f92cf041ee624c173ee ] The helper->expect_class_max must be set to the total number of expect_policy minus 1, since we will use the statement "if (class > helper->expect_class_max)" to validate the CTA_EXPECT_CLASS attr in ctnetlink_alloc_expect. So for compatibility, set the helper->expect_class_max to the NFCTH_POLICY_SET_NUM attr's value minus 1. Also: it's invalid when the NFCTH_POLICY_SET_NUM attr's value is zero. 1. this will result "expect_policy = kzalloc(0, GFP_KERNEL);"; 2. we cannot set the helper->expect_class_max to a proper value. So if nla_get_be32(tb[NFCTH_POLICY_SET_NUM]) is zero, report -EINVAL to the userspace. 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>
2015-07-13netfilter: Zero the tuple in nfnl_cthelper_parse_tuple()Ian Wilson1-0/+3
[ Upstream commit 78146572b9cd20452da47951812f35b1ad4906be ] nfnl_cthelper_parse_tuple() is called from nfnl_cthelper_new(), nfnl_cthelper_get() and nfnl_cthelper_del(). In each case they pass a pointer to an nf_conntrack_tuple data structure local variable: struct nf_conntrack_tuple tuple; ... ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]); The problem is that this local variable is not initialized, and nfnl_cthelper_parse_tuple() only initializes two fields: src.l3num and dst.protonum. This leaves all other fields with undefined values based on whatever is on the stack: tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); The symptom observed was that when the rpc and tns helpers were added then traffic to port 1536 was being sent to user-space. Signed-off-by: Ian Wilson <iwilson@brocade.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-07-12netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warningsChen Gang1-2/+2
[ Upstream commit b18c5d15e8714336365d9d51782d5b53afa0443c ] The related code can be simplified, and also can avoid related warnings (with allmodconfig under parisc): CC [M] net/netfilter/nfnetlink_cthelper.o net/netfilter/nfnetlink_cthelper.c: In function ‘nfnl_cthelper_from_nlattr’: net/netfilter/nfnetlink_cthelper.c:97:9: warning: passing argument 1 o ‘memcpy’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-array-qualifiers] memcpy(&help->data, nla_data(attr), help->helper->data_len); ^ In file included from include/linux/string.h:17:0, from include/uapi/linux/uuid.h:25, from include/linux/uuid.h:23, from include/linux/mod_devicetable.h:12, from ./arch/parisc/include/asm/hardware.h:4, from ./arch/parisc/include/asm/processor.h:15, from ./arch/parisc/include/asm/spinlock.h:6, from ./arch/parisc/include/asm/atomic.h:21, from include/linux/atomic.h:4, from ./arch/parisc/include/asm/bitops.h:12, from include/linux/bitops.h:36, from include/linux/kernel.h:10, from include/linux/list.h:8, from include/linux/module.h:9, from net/netfilter/nfnetlink_cthelper.c:11: ./arch/parisc/include/asm/string.h:8:8: note: expected ‘void *’ but argument is of type ‘const char (*)[]’ void * memcpy(void * dest,const void *src,size_t count); ^ Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@soleta.eu> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2013-06-20netfilter: check return code from nla_parse_testedDaniel Borkmann1-4/+12
These are the only calls under net/ that do not check nla_parse_nested() for its error code, but simply continue execution. If parsing of netlink attributes fails, we should return with an error instead of continuing. In nearly all of these calls we have a policy attached, that is being type verified during nla_parse_nested(), which we would miss checking for otherwise. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-28hlist: drop the node parameter from iteratorsSasha Levin1-10/+7
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-24netfilter: nf_ct_ftp: add sequence tracking pickup facility for injected entriesPablo Neira Ayuso1-0/+3
This patch allows the FTP helper to pickup the sequence tracking from the first packet seen. This is useful to fix the breakage of the first FTP command after the failover while using conntrackd to synchronize states. The seq_aft_nl_num field in struct nf_ct_ftp_info has been shrinked to 16-bits (enough for what it does), so we can use the remaining 16-bits to store the flags while using the same size for the private FTP helper data. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-09-10netlink: Rename pid to portid to avoid confusionEric W. Biederman1-6/+6
It is a frequent mistake to confuse the netlink port identifier with a process identifier. Try to reduce this confusion by renaming fields that hold port identifiers portid instead of pid. I have carefully avoided changing the structures exported to userspace to avoid changing the userspace API. I have successfully built an allyesconfig kernel with this change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-20netfilter: sparse endian fixesPatrick McHardy1-1/+1
Fix a couple of endian annotation in net/netfilter: net/netfilter/nfnetlink_acct.c:82:30: warning: cast to restricted __be64 net/netfilter/nfnetlink_acct.c:86:30: warning: cast to restricted __be64 net/netfilter/nfnetlink_cthelper.c:77:28: warning: cast to restricted __be16 net/netfilter/xt_NFQUEUE.c:46:16: warning: restricted __be32 degrades to integer net/netfilter/xt_NFQUEUE.c:60:34: warning: restricted __be32 degrades to integer net/netfilter/xt_NFQUEUE.c:68:34: warning: restricted __be32 degrades to integer net/netfilter/xt_osf.c:272:55: warning: cast to restricted __be16 Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16netfilter: add user-space connection tracking helper infrastructurePablo Neira Ayuso1-0/+672
There are good reasons to supports helpers in user-space instead: * Rapid connection tracking helper development, as developing code in user-space is usually faster. * Reliability: A buggy helper does not crash the kernel. Moreover, we can monitor the helper process and restart it in case of problems. * Security: Avoid complex string matching and mangling in kernel-space running in privileged mode. Going further, we can even think about running user-space helpers as a non-root process. * Extensibility: It allows the development of very specific helpers (most likely non-standard proprietary protocols) that are very likely not to be accepted for mainline inclusion in the form of kernel-space connection tracking helpers. This patch adds the infrastructure to allow the implementation of user-space conntrack helpers by means of the new nfnetlink subsystem `nfnetlink_cthelper' and the existing queueing infrastructure (nfnetlink_queue). I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into two pieces. This change is required not to break NAT sequence adjustment and conntrack confirmation for traffic that is enqueued to our user-space conntrack helpers. Basic operation, in a few steps: 1) Register user-space helper by means of `nfct': nfct helper add ftp inet tcp [ It must be a valid existing helper supported by conntrack-tools ] 2) Add rules to enable the FTP user-space helper which is used to track traffic going to TCP port 21. For locally generated packets: iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp For non-locally generated packets: iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp 3) Run the test conntrackd in helper mode (see example files under doc/helper/conntrackd.conf conntrackd 4) Generate FTP traffic going, if everything is OK, then conntrackd should create expectations (you can check that with `conntrack': conntrack -E expect [NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp [DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp This confirms that our test helper is receiving packets including the conntrack information, and adding expectations in kernel-space. The user-space helper can also store its private tracking information in the conntrack structure in the kernel via the CTA_HELP_INFO. The kernel will consider this a binary blob whose layout is unknown. This information will be included in the information that is transfered to user-space via glue code that integrates nfnetlink_queue and ctnetlink. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>