user/sven/linux.git/net, branch v3.18.37

netfilter: x_tables: introduce and use xt_copy_counters_from_user

2016-07-12T12:48:37Z

[ Upstream commit d7591f0c41ce3e67600a982bab6989ef0f07b3ce ] 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: Sasha Levin

netfilter: x_tables: do compat validation via translate_table

2016-07-12T12:48:37Z

[ Upstream commit 09d9686047dbbe1cf4faa558d3ecc4aae2046054 ] 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: Sasha Levin

netfilter: x_tables: xt_compat_match_from_user doesn't need a retval

2016-07-12T12:48:36Z

[ Upstream commit 0188346f21e6546498c2a0f84888797ad4063fc5 ] Always returned 0. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: ip6_tables: simplify translate_compat_table args

2016-07-12T12:48:36Z

[ Upstream commit 329a0807124f12fe1c8032f95d8a8eb47047fb0e ] Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: ip_tables: simplify translate_compat_table args

2016-07-12T12:48:35Z

[ Upstream commit 7d3f843eed29222254c9feab481f55175a1afcc9 ] Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: arp_tables: simplify translate_compat_table args

2016-07-12T12:48:34Z

[ Upstream commit 8dddd32756f6fe8e4e82a63361119b7e2384e02f ] Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: x_tables: don't reject valid target size on some architectures

2016-07-12T12:48:34Z

[ Upstream commit 7b7eba0f3515fca3296b8881d583f7c1042f5226 ] Quoting John Stultz: In updating a 32bit arm device from 4.6 to Linus' current HEAD, I noticed I was having some trouble with networking, and realized that /proc/net/ip_tables_names was suddenly empty. Digging through the registration process, it seems we're catching on the: if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && target_offset + sizeof(struct xt_standard_target) != next_offset) return -EINVAL; Where next_offset seems to be 4 bytes larger then the offset + standard_target struct size. next_offset needs to be aligned via XT_ALIGN (so we can access all members of ip(6)t_entry struct). This problem didn't show up on i686 as it only needs 4-byte alignment for u64, but iptables userspace on other 32bit arches does insert extra padding. Reported-by: John Stultz Tested-by: John Stultz Fixes: 7ed2abddd20cf ("netfilter: x_tables: check standard target size too") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: x_tables: validate all offsets and sizes in a rule

2016-07-12T12:48:33Z

[ Upstream commit 13631bfc604161a9d69cd68991dff8603edd66f9 ] Validate that all matches (if any) add up to the beginning of the target and that each match covers at least the base structure size. The compat path should be able to safely re-use the function as the structures only differ in alignment; added a BUILD_BUG_ON just in case we have an arch that adds padding as well. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: x_tables: check for bogus target offset

2016-07-12T12:48:33Z

[ Upstream commit ce683e5f9d045e5d67d1312a42b359cb2ab2a13c ] 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: Sasha Levin

netfilter: x_tables: check standard target size too

2016-07-12T12:48:32Z

[ Upstream commit 7ed2abddd20cf8f6bd27f65bd218f26fa5bf7f44 ] We have targets and standard targets -- the latter carries a verdict. The ip/ip6tables validation functions will access t->verdict for the standard targets to fetch the jump offset or verdict for chainloop detection, but this happens before the targets get checked/validated. Thus we also need to check for verdict presence here, else t->verdict can point right after a blob. Spotted with UBSAN while testing malformed blobs. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin