linux/include/net/netfilter, branch v4.9

netfilter: nat: fix crash when conntrack entry is re-used

2016-11-24T13:43:35Z

Stas Nichiporovich reports oops in nf_nat_bysource_cmp(), trying to access nf_conn struct at address 0xffffffffffffff50. This is the result of fetching a null rhash list (struct embedded at offset 176; 0 - 176 gets us ...fff50). The problem is that conntrack entries are allocated from a SLAB_DESTROY_BY_RCU cache, i.e. entries can be free'd and reused on another cpu while nf nat bysource hash access the same conntrack entry. Freeing is fine (we hold rcu read lock); zeroing rhlist_head isn't. -> Move the rhlist struct outside of the memset()-inited area. Fixes: 7c9664351980aaa6a ("netfilter: move nat hlist_head to nf_conn") Reported-by: Stas Nichiporovich Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix inconsistent element expiration calculation

2016-11-24T13:43:34Z

As Liping Zhang reports, after commit a8b1e36d0d1d ("netfilter: nft_dynset: fix element timeout for HZ != 1000"), priv->timeout was stored in jiffies, while set->timeout was stored in milliseconds. This is inconsistent and incorrect. Firstly, we already call msecs_to_jiffies in nft_set_elem_init, so priv->timeout will be converted to jiffies twice. Secondly, if the user did not specify the NFTA_DYNSET_TIMEOUT attr, set->timeout will be used, but we forget to call msecs_to_jiffies when do update elements. Fix this by using jiffies internally for traditional sets and doing the conversions to/from msec when interacting with userspace - as dynset already does. This is preferable to doing the conversions, when elements are inserted or updated, because this can happen very frequently on busy dynsets. Fixes: a8b1e36d0d1d ("netfilter: nft_dynset: fix element timeout for HZ != 1000") Reported-by: Liping Zhang Signed-off-by: Anders K. Pedersen Acked-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso

netfilter: nat: switch to new rhlist interface

2016-11-24T13:43:34Z

I got offlist bug report about failing connections and high cpu usage. This happens because we hit 'elasticity' checks in rhashtable that refuses bucket list exceeding 16 entries. The nat bysrc hash unfortunately needs to insert distinct objects that share same key and are identical (have same source tuple), this cannot be avoided. Switch to the rhlist interface which is designed for this. The nulls_base is removed here, I don't think its needed: A (unlikely) false positive results in unneeded port clash resolution, a false negative results in packet drop during conntrack confirmation, when we try to insert the duplicate into main conntrack hash table. Tested by adding multiple ip addresses to host, then adding iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE ... and then creating multiple connections, from same source port but different addresses: for i in $(seq 2000 2032);do nc -p 1234 192.168.7.1 $i > /dev/null & done (all of these then get hashed to same bysource slot) Then, to test that nat conflict resultion is working: nc -s 10.0.0.1 -p 1234 192.168.7.1 2000 nc -s 10.0.0.2 -p 1234 192.168.7.1 2000 tcp .. src=10.0.0.1 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1024 [ASSURED] tcp .. src=10.0.0.2 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1025 [ASSURED] tcp .. src=192.168.7.10 dst=192.168.7.1 sport=1234 dport=2000 src=192.168.7.1 dst=192.168.7.10 sport=2000 dport=1234 [ASSURED] tcp .. src=192.168.7.10 dst=192.168.7.1 sport=1234 dport=2001 src=192.168.7.1 dst=192.168.7.10 sport=2001 dport=1234 [ASSURED] [..] -> nat altered source ports to 1024 and 1025, respectively. This can also be confirmed on destination host which shows ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1024 ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1025 ESTAB 0 0 192.168.7.1:2000 192.168.7.10:1234 Cc: Herbert Xu Fixes: 870190a9ec907 ("netfilter: nat: convert nat bysrc hash to rhashtable") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: avoid excess memory allocation

2016-10-27T16:29:02Z

This is now a fixed-size extension, so we don't need to pass a variable alloc size. This (harmless) error results in allocating 32 instead of the needed 16 bytes for this extension as the size gets passed twice. Fixes: 23014011ba420 ("netfilter: conntrack: support a fixed size of 128 distinct labels") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix type mismatch with error return from nft_parse_u32_check

2016-10-27T16:29:01Z

Commit 36b701fae12ac ("netfilter: nf_tables: validate maximum value of u32 netlink attributes") introduced nft_parse_u32_check with a return value of "unsigned int", yet on error it returns "-ERANGE". This patch corrects the mismatch by changing the return value to "int", which happens to match the actual users of nft_parse_u32_check already. Found by Coverity, CID 1373930. Note that commit 21a9e0f1568ea ("netfilter: nft_exthdr: fix error handling in nft_exthdr_init()) attempted to address the issue, but did not address the return type of nft_parse_u32_check. Signed-off-by: John W. Linville Cc: Laura Garcia Liebana Cc: Pablo Neira Ayuso Cc: Dan Carpenter Fixes: 36b701fae12ac ("netfilter: nf_tables: validate maximum value...") Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix leak when expr clone fail

2016-10-27T16:20:45Z

When nft_expr_clone failed, a series of problems will happen: 1. module refcnt will leak, we call __module_get at the beginning but we forget to put it back if ops->clone returns fail 2. memory will be leaked, if clone fail, we just return NULL and forget to free the alloced element 3. set->nelems will become incorrect when set->size is specified. If clone fail, we should decrease the set->nelems Now this patch fixes these problems. And fortunately, clone fail will only happen on counter expression when memory is exhausted. Fixes: 086f332167d6 ("netfilter: nf_tables: add clone interface to expression operations") Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso

netfilter: merge fixup for "nf_tables_netdev: remove redundant ip_hdr assignment"

2016-10-06T00:25:48Z

Signed-off-by: Stephen Rothwell Acked-by: Pablo Neira Ayuso Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2016-09-25T21:34:19Z

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

netfilter: nft_log: complete NFTA_LOG_FLAGS attr support

2016-09-25T21:16:43Z

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 Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add range expression

2016-09-25T21:16:42Z

Inverse ranges != [a,b] are not currently possible because rules are composites of && operations, and we need to express this: data < a || data > b This patch adds a new range expression. Positive ranges can be already through two cmp expressions: cmp(sreg, data, >=) cmp(sreg, data, <=) This new range expression provides an alternative way to express this. Signed-off-by: Pablo Neira Ayuso