user/sven/linux.git/net/ipv4, branch v4.6.3

netfilter: x_tables: introduce and use xt_copy_counters_from_user

2016-06-24T17:22:06Z

commit d7591f0c41ce3e67600a982bab6989ef0f07b3ce upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: do compat validation via translate_table

2016-06-24T17:22:06Z

commit 09d9686047dbbe1cf4faa558d3ecc4aae2046054 upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: xt_compat_match_from_user doesn't need a retval

2016-06-24T17:22:06Z

commit 0188346f21e6546498c2a0f84888797ad4063fc5 upstream. Always returned 0. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: ip_tables: simplify translate_compat_table args

2016-06-24T17:22:06Z

commit 7d3f843eed29222254c9feab481f55175a1afcc9 upstream. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: arp_tables: simplify translate_compat_table args

2016-06-24T17:22:06Z

commit 8dddd32756f6fe8e4e82a63361119b7e2384e02f upstream. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: check for bogus target offset

2016-06-24T17:22:05Z

commit ce683e5f9d045e5d67d1312a42b359cb2ab2a13c upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: add compat version of xt_check_entry_offsets

2016-06-24T17:22:05Z

commit fc1221b3a163d1386d1052184202d5dc50d302d1 upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: kill check_entry helper

2016-06-24T17:22:05Z

commit aa412ba225dd3bc36d404c28cdc3d674850d80d0 upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: add and use xt_check_entry_offsets

2016-06-24T17:22:05Z

commit 7d35812c3214afa5b37a675113555259cfd67b98 upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: validate targets of jumps

2016-06-24T17:22:05Z

commit 36472341017529e2b12573093cc0f68719300997 upstream. 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman