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2023-01-21netlink: prevent potential spectre v1 gadgetsEric Dumazet1-0/+3
Most netlink attributes are parsed and validated from __nla_validate_parse() or validate_nla() u16 type = nla_type(nla); if (type == 0 || type > maxtype) { /* error or continue */ } @type is then used as an array index and can be used as a Spectre v1 gadget. array_index_nospec() can be used to prevent leaking content of kernel memory to malicious users. This should take care of vast majority of netlink uses, but an audit is needed to take care of others where validation is not yet centralized in core netlink functions. Fixes: bfa83a9e03cf ("[NETLINK]: Type-safe netlink messages/attributes interface") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230119110150.2678537-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-09lib: Fix some kernel-doc commentsYang Li1-1/+1
Make the description of @policy to @p in nla_policy_len() to clear the below warnings: lib/nlattr.c:660: warning: Function parameter or member 'p' not described in 'nla_policy_len' lib/nlattr.c:660: warning: Excess function parameter 'policy' description in 'nla_policy_len' Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2736 Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/20221107062623.6709-1-yang.lee@linux.alibaba.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-02netlink: introduce bigendian integer typesFlorian Westphal1-26/+15
Jakub reported that the addition of the "network_byte_order" member in struct nla_policy increases size of 32bit platforms. Instead of scraping the bit from elsewhere Johannes suggested to add explicit NLA_BE types instead, so do this here. NLA_POLICY_MAX_BE() macro is removed again, there is no need for it: NLA_POLICY_MAX(NLA_BE.., ..) will do the right thing. NLA_BE64 can be added later. Fixes: 08724ef69907 ("netlink: introduce NLA_POLICY_MAX_BE") Reported-by: Jakub Kicinski <kuba@kernel.org> Suggested-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20221031123407.9158-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-07netlink: introduce NLA_POLICY_MAX_BEFlorian Westphal1-4/+27
netlink allows to specify allowed ranges for integer types. Unfortunately, nfnetlink passes integers in big endian, so the existing NLA_POLICY_MAX() cannot be used. At the moment, nfnetlink users, such as nf_tables, need to resort to programmatic checking via helpers such as nft_parse_u32_check(). This is both cumbersome and error prone. This adds NLA_POLICY_MAX_BE which adds range check support for BE16, BE32 and BE64 integers. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-08lib: fix spelling mistakesZhen Lei1-2/+2
Fix some spelling mistakes in comments: permanentely ==> permanently wont ==> won't remaning ==> remaining succed ==> succeed shouldnt ==> shouldn't alpha-numeric ==> alphanumeric storeing ==> storing funtion ==> function documenation ==> documentation Determin ==> Determine intepreted ==> interpreted ammount ==> amount obious ==> obvious interupts ==> interrupts occured ==> occurred asssociated ==> associated taking into acount ==> taking into account squence ==> sequence stil ==> still contiguos ==> contiguous matchs ==> matches Link: https://lkml.kernel.org/r/20210607072555.12416-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05net: fix nla_strcmp to handle more then one trailing null characterMaciej Żenczykowski1-1/+1
Android userspace has been using TCA_KIND with a char[IFNAMESIZ] many-null-terminated buffer containing the string 'bpf'. This works on 4.19 and ceases to work on 5.10. I'm not entirely sure what fixes tag to use, but I think the issue was likely introduced in the below mentioned 5.4 commit. Reported-by: Nucca Chen <nuccachen@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@mellanox.com> Cc: Jiri Pirko <jiri@resnulli.us> Fixes: 62794fc4fbf5 ("net_sched: add max len check for TCA_KIND") Change-Id: I66dc281f165a2858fc29a44869a270a2d698a82b Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-16Merge tag 'fallthrough-fixes-clang-5.11-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux Pull fallthrough fixes from Gustavo A. R. Silva: "Fix many fall-through warnings when building with Clang 12.0.0 using -Wimplicit-fallthrough. - powerpc: boot: include compiler_attributes.h (Nick Desaulniers) - Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" (Nick Desaulniers) - powerpc: fix -Wimplicit-fallthrough (Nick Desaulniers) - lib: Fix fall-through warnings for Clang (Gustavo A. R. Silva)" * tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: lib: Fix fall-through warnings for Clang powerpc: fix -Wimplicit-fallthrough Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" powerpc: boot: include compiler_attributes.h
2020-11-19lib: Fix fall-through warnings for ClangGustavo A. R. Silva1-1/+1
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple break statements instead of letting the code fall through to the next case, and by replacing a number of /* fall through */ comments with the new pseudo-keyword macro fallthrough. Notice that Clang doesn't recognize /* Fall through */ comments as implicit fall-through markings. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-11-16treewide: rename nla_strlcpy to nla_strscpy.Francis Laniel1-3/+3
Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new name of this function. Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16Modify return value of nla_strlcpy to match that of strscpy.Francis Laniel1-14/+25
nla_strlcpy now returns -E2BIG if src was truncated when written to dst. It also returns this error value if dstsize is 0 or higher than INT_MAX. For example, if src is "foo\0" and dst is 3 bytes long, the result will be: 1. "foG" after memcpy (G means garbage). 2. "fo\0" after memset. 3. -E2BIG is returned because src was not completely written into dst. The callers of nla_strlcpy were modified to take into account this modification. Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16Fix unefficient call to memset before memcpu in nla_strlcpy.Francis Laniel1-1/+2
Before this commit, nla_strlcpy first memseted dst to 0 then wrote src into it. This is inefficient because bytes whom number is less than src length are written twice. This patch solves this issue by first writing src into dst then fill dst with 0's. Note that, in the case where src length is higher than dst, only 0 is written. Otherwise there are as many 0's written to fill dst. For example, if src is "foo\0" and dst is 5 bytes long, the result will be: 1. "fooGG" after memcpy (G means garbage). 2. "foo\0\0" after memset. Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10netlink: export policy in extended ACKJohannes Berg1-17/+18
Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK to advertise the policy, e.g. if an attribute was out of range, you'll know the range that's permissible. Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL() macros to set this, since realistically it's only useful to do this when the bad attribute (offset) is also returned. Use it in lib/nlattr.c which practically does all the policy validation. v2: - add and use netlink_policy_dump_attr_size_estimate() v3: - remove redundant break v4: - really remove redundant break ... sorry Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-06netlink: add mask validationJakub Kicinski1-0/+36
We don't have good validation policy for existing unsigned int attrs which serve as flags (for new ones we could use NLA_BITFIELD32). With increased use of policy dumping having the validation be expressed as part of the policy is important. Add validation policy in form of a mask of supported/valid bits. Support u64 in the uAPI to be future-proof, but really for now the embedded mask member can only hold 32 bits, so anything with bit 32+ set will always fail validation. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25netlink: remove duplicated nla_need_padding_for_64bit() checkMiaohe Lin1-2/+1
The need for padding 64bit is implicitly checked by nla_align_64bit(), so remove this explicit one. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18netlink: make NLA_BINARY validation more flexibleJohannes Berg1-21/+39
Add range validation for NLA_BINARY, allowing validation of any combination of combination minimum or maximum lengths, using the existing NLA_POLICY_RANGE()/NLA_POLICY_FULL_RANGE() macros, just like for integers where the value is checked. Also make NLA_POLICY_EXACT_LEN(), NLA_POLICY_EXACT_LEN_WARN() and NLA_POLICY_MIN_LEN() special cases of this, removing the old types NLA_EXACT_LEN and NLA_MIN_LEN. This allows us to save some code where both minimum and maximum lengths are requires, currently the policy only allows maximum (NLA_BINARY), minimum (NLA_MIN_LEN) or exact (NLA_EXACT_LEN), so a range of lengths cannot be accepted and must be checked by the code that consumes the attributes later. Also, this allows advertising the correct ranges in the policy export to userspace. Here, NLA_MIN_LEN and NLA_EXACT_LEN already were special cases of NLA_BINARY with min and min/max length respectively. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: factor out policy range helpersJohannes Berg1-21/+74
Add helpers to get the policy's signed/unsigned range validation data. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: remove NLA_EXACT_LEN_WARNJohannes Berg1-6/+10
Use a validation type instead, so we can later expose the NLA_* values to userspace for policy descriptions. Some transformations were done with this spatch: @@ identifier p; expression X, L, A; @@ struct nla_policy p[X] = { [A] = -{ .type = NLA_EXACT_LEN_WARN, .len = L }, +NLA_POLICY_EXACT_LEN_WARN(L), ... }; Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: allow NLA_MSECS to have range validationJohannes Berg1-0/+2
Since NLA_MSECS is really equivalent to NLA_U64, allow it to have range validation as well. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: extend policy range validationJohannes Berg1-21/+92
Using a pointer to a struct indicating the min/max values, extend the ability to do range validation for arbitrary values. Small values in the s16 range can be kept in the policy directly. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: limit recursion depth in policy validationJohannes Berg1-12/+34
Now that we have nested policies, we can theoretically recurse forever parsing attributes if a (sub-)policy refers back to a higher level one. This is a situation that has happened in nl80211, and we've avoided it there by not linking it. Add some code to netlink parsing to limit recursion depth. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01netlink: remove type-unsafe validation_data pointerJohannes Berg1-10/+10
In the netlink policy, we currently have a void *validation_data that's pointing to different things: * a u32 value for bitfield32, * the netlink policy for nested/nested array * the string for NLA_REJECT Remove the pointer and place appropriate type-safe items in the union instead. While at it, completely dissolve the pointer for the bitfield32 case and just put the value there directly. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-04netlink: add validation of NLA_F_NESTED flagMichal Kubecek1-0/+15
Add new validation flag NL_VALIDATE_NESTED which adds three consistency checks of NLA_F_NESTED_FLAG: - the flag is set on attributes with NLA_NESTED{,_ARRAY} policy - the flag is not set on attributes with other policies except NLA_UNSPEC - the flag is set on attribute passed to nla_parse_nested() Signed-off-by: Michal Kubecek <mkubecek@suse.cz> v2: change error messages to mention NLA_F_NESTED explicitly Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-04netlink: set bad attribute also on maxtype checkMichal Kubecek1-1/+2
The check that attribute type is within 0...maxtype range in __nla_validate_parse() sets only error message but not bad_attr in extack. Set also bad_attr to tell userspace which attribute failed validation. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-28netlink: add strict parsing for future attributesJohannes Berg1-0/+4
Unfortunately, we cannot add strict parsing for all attributes, as that would break existing userspace. We currently warn about it, but that's about all we can do. For new attributes, however, the story is better: nobody is using them, so we can reject bad sizes. Also, for new attributes, we need not accept them when the policy doesn't declare their usage. David Ahern and I went back and forth on how to best encode this, and the best way we found was to have a "boundary type", from which point on new attributes have all possible validation applied, and NLA_UNSPEC is rejected. As we didn't want to add another argument to all functions that get a netlink policy, the workaround is to encode that boundary in the first entry of the policy array (which is for type 0 and thus probably not really valid anyway). I put it into the validation union for the rare possibility that somebody is actually using attribute 0, which would continue to work fine unless they tried to use the extended validation, which isn't likely. We also didn't find any in-tree users with type 0. The reason for setting the "start strict here" attribute is that we never really need to start strict from 0, which is invalid anyway (or in legacy families where that isn't true, it cannot be set to strict), so we can thus reserve the value 0 for "don't do this check" and don't have to add the tag to all policies right now. Thus, policies can now opt in to this validation, which we should do for all existing policies, at least when adding new attributes. Note that entirely *new* policies won't need to set it, as the use of that should be using nla_parse()/nlmsg_parse() etc. which anyway do fully strict validation now, regardless of this. So in effect, this patch only covers the "existing command with new attribute" case. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-28netlink: make validation more configurable for future strictnessJohannes Berg1-83/+88
We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-28netlink: add NLA_MIN_LENJohannes Berg1-1/+8
Rather than using NLA_UNSPEC for this type of thing, use NLA_MIN_LEN so we can make NLA_UNSPEC be NLA_REJECT under certain conditions for future attributes. While at it, also use NLA_EXACT_LEN for the struct example. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-08netlink: Add strict version of nlmsg_parse and nla_parseDavid Ahern1-12/+36
nla_parse is currently lenient on message parsing, allowing type to be 0 or greater than max expected and only logging a message "netlink: %d bytes leftover after parsing attributes in process `%s'." if the netlink message has unknown data at the end after parsing. What this could mean is that the header at the front of the attributes is actually wrong and the parsing is shifted from what is expected. Add a new strict version that actually fails with EINVAL if there are any bytes remaining after the parsing loop completes, if the atttrbitue type is 0 or greater than max expected. Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Christian Brauner <christian@brauner.io> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-02netlink: add validation function to policyJohannes Berg1-0/+7
Add the ability to have an arbitrary validation function attached to a netlink policy that doesn't already use the validation_data pointer in another way. This can be useful to validate for example the content of a binary attribute, like in nl80211 the "(information) elements", which must be valid streams of "u8 type, u8 length, u8 value[length]". Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-02netlink: add attribute range validation to policyJohannes Berg1-0/+72
Without further bloating the policy structs, we can overload the `validation_data' pointer with a struct of s16 min, max and use those to validate ranges in NLA_{U,S}{8,16,32,64} attributes. It may sound strange to validate NLA_U32 with a s16 max, but in many cases NLA_U32 is used for enums etc. since there's no size benefit in using a smaller attribute width anyway, due to netlink attribute alignment; in cases like that it's still useful, particularly when the attribute really transports an enum value. Doing so lets us remove quite a bit of validation code, if we can be sure that these attributes aren't used by userspace in places where they're ignored today. To achieve all this, split the 'type' field and introduce a new 'validation_type' field which indicates what further validation (beyond the validation prescribed by the type of the attribute) is done. This currently allows for no further validation (the default), as well as min, max and range checks. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28netlink: add nested array policy validationJohannes Berg1-0/+51
Sometimes nested netlink attributes are just used as arrays, with the nla_type() of each not being used; we have this in nl80211 and e.g. NFTA_SET_ELEM_LIST_ELEMENTS. Add the ability to validate this type of message directly in the policy, by adding the type NLA_NESTED_ARRAY which does exactly this: require a first level of nesting but ignore the attribute type, and then inside each require a second level of nested and validate those attributes against a given policy (if present). Note that some nested array types actually require that all of the entries have the same index, this is possible to express in a nested policy already, apart from the validation that only the one allowed type is used. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28netlink: allow NLA_NESTED to specify nested policy to validateJohannes Berg1-0/+14
Now that we have a validation_data pointer, and the len field in the policy is unused for NLA_NESTED, we can allow using them both to have nested validation. This can be nice in code, although we still have to use nla_parse_nested() or similar which would also take a policy; however, it also serves as documentation in the policy without requiring a look at the code. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28netlink: move extack setting into validate_nla()Johannes Berg1-32/+36
This unifies the code between nla_parse() which sets the bad attribute pointer and an error message, and nla_validate() which only sets the bad attribute pointer. It also cleans up the code for NLA_REJECT and paves the way for nested policy validation, as it will allow us to easily skip setting the "generic" message without any extra args like the **error_msg now, just passing the extack through is now enough. While at it, remove the unnecessary label in nla_parse(). Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28netlink: make validation_data constJohannes Berg1-3/+2
The validation data is only used within the policy that should usually already be const, and isn't changed in any code that uses it. Therefore, make the validation_data pointer const. While at it, remove the duplicate variable in the bitfield validation that I'd otherwise have to change to const. Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-28netlink: remove NLA_NESTED_COMPATJohannes Berg1-11/+0
This isn't used anywhere, so we might as well get rid of it. Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-19netlink: add ethernet address policy typesJohannes Berg1-1/+7
Commonly, ethernet addresses are just using a policy of { .len = ETH_ALEN } which leaves userspace free to send more data than it should, which may hide bugs. Introduce NLA_EXACT_LEN which checks for exact size, rejecting the attribute if it's not exactly that length. Also add NLA_EXACT_LEN_WARN which requires the minimum length and will warn on longer attributes, for backward compatibility. Use these to define NLA_POLICY_ETH_ADDR (new strict policy) and NLA_POLICY_ETH_ADDR_COMPAT (compatible policy with warning); these are used like this: static const struct nla_policy <name>[...] = { [NL_ATTR_NAME] = NLA_POLICY_ETH_ADDR, ... }; Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-19netlink: add NLA_REJECT policy typeJohannes Berg1-7/+16
In some situations some netlink attributes may be used for output only (kernel->userspace) or may be reserved for future use. It's then helpful to be able to prevent userspace from using them in messages sent to the kernel, since they'd otherwise be ignored and any future will become impossible if this happens. Add NLA_REJECT to the policy which does nothing but reject (with EINVAL) validation of any messages containing this attribute. Allow for returning a specific extended ACK error message in the validation_data pointer. While at it clear up the documentation a bit - the NLA_BITFIELD32 documentation was added to the list of len field descriptions. Also, use NL_SET_BAD_ATTR() in one place where it's open-coded. The specific case I have in mind now is a shared nested attribute containing request/response data, and it would be pointless and potentially confusing to have userspace include response data in the messages that actually contain a request. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28netlink: Return extack message if attribute validation failsDavid Ahern1-2/+2
Have one extack message for parsing and validating. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-07netlink: Relax attr validation for fixed length typesDavid Ahern1-6/+16
Commit 28033ae4e0f5 ("net: netlink: Update attr validation to require exact length for some types") requires attributes using types NLA_U* and NLA_S* to have an exact length. This change is exposing bugs in various userspace commands that are sending attributes with an invalid length (e.g., attribute has type NLA_U8 and userspace sends NLA_U32). While the commands are clearly broken and need to be fixed, users are arguing that the sudden change in enforcement is breaking older commands on newer kernels for use cases that otherwise "worked". Relax the validation to print a warning mesage similar to what is done for messages containing extra bytes after parsing. Fixes: 28033ae4e0f5 ("net: netlink: Update attr validation to require exact length for some types") Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11net: netlink: Update attr validation to require exact length for some typesDavid Ahern1-3/+16
Attributes using NLA_U* and NLA_S* (where * is 8, 16,32 and 64) are expected to be an exact length. Split these data types from nla_attr_minlen into nla_attr_len and update validate_nla to require the attribute to have exact length for them. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-0/+24
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree. Basically, updates to the conntrack core, enhancements for nf_tables, conversion of netfilter hooks from linked list to array to improve memory locality and asorted improvements for the Netfilter codebase. More specifically, they are: 1) Add expection to hashes after timer initialization to prevent access from another CPU that walks on the hashes and calls del_timer(), from Florian Westphal. 2) Don't update nf_tables chain counters from hot path, this is only used by the x_tables compatibility layer. 3) Get rid of nested rcu_read_lock() calls from netfilter hook path. Hooks are always guaranteed to run from rcu read side, so remove nested rcu_read_lock() where possible. Patch from Taehee Yoo. 4) nf_tables new ruleset generation notifications include PID and name of the process that has updated the ruleset, from Phil Sutter. 5) Use skb_header_pointer() from nft_fib, so we can reuse this code from the nf_family netdev family. Patch from Pablo M. Bermudo. 6) Add support for nft_fib in nf_tables netdev family, also from Pablo. 7) Use deferrable workqueue for conntrack garbage collection, to reduce power consumption, from Patch from Subash Abhinov Kasiviswanathan. 8) Add nf_ct_expect_iterate_net() helper and use it. From Florian Westphal. 9) Call nf_ct_unconfirmed_destroy only from cttimeout, from Florian. 10) Drop references on conntrack removal path when skbuffs has escaped via nfqueue, from Florian. 11) Don't queue packets to nfqueue with dying conntrack, from Florian. 12) Constify nf_hook_ops structure, from Florian. 13) Remove neededlessly branch in nf_tables trace code, from Phil Sutter. 14) Add nla_strdup(), from Phil Sutter. 15) Rise nf_tables objects name size up to 255 chars, people want to use DNS names, so increase this according to what RFC 1035 specifies. Patch series from Phil Sutter. 16) Kill nf_conntrack_default_on, it's broken. Default on conntrack hook registration on demand, suggested by Eric Dumazet, patch from Florian. 17) Remove unused variables in compat_copy_entry_from_user both in ip_tables and arp_tables code. Patch from Taehee Yoo. 18) Constify struct nf_conntrack_l4proto, from Julia Lawall. 19) Constify nf_loginfo structure, also from Julia. 20) Use a single rb root in connlimit, from Taehee Yoo. 21) Remove unused netfilter_queue_init() prototype, from Taehee Yoo. 22) Use audit_log() instead of open-coding it, from Geliang Tang. 23) Allow to mangle tcp options via nft_exthdr, from Florian. 24) Allow to fetch TCP MSS from nft_rt, from Florian. This includes a fix for a miscalculation of the minimal length. 25) Simplify branch logic in h323 helper, from Nick Desaulniers. 26) Calculate netlink attribute size for conntrack tuple at compile time, from Florian. 27) Remove protocol name field from nf_conntrack_{l3,l4}proto structure. From Florian. 28) Remove holes in nf_conntrack_l4proto structure, so it becomes smaller. From Florian. 29) Get rid of print_tuple() indirection for /proc conntrack listing. Place all the code in net/netfilter/nf_conntrack_standalone.c. Patch from Florian. 30) Do not built in print_conntrack() if CONFIG_NF_CONNTRACK_PROCFS is off. From Florian. 31) Constify most nf_conntrack_{l3,l4}proto helper functions, from Florian. 32) Fix broken indentation in ebtables extensions, from Colin Ian King. 33) Fix several harmless sparse warning, from Florian. 34) Convert netfilter hook infrastructure to use array for better memory locality, joint work done by Florian and Aaron Conole. Moreover, add some instrumentation to debug this. 35) Batch nf_unregister_net_hooks() calls, to call synchronize_net once per batch, from Florian. 36) Get rid of noisy logging in ICMPv6 conntrack helper, from Florian. 37) Get rid of obsolete NFDEBUG() instrumentation, from Varsha Rao. 38) Remove unused code in the generic protocol tracker, from Davide Caratti. I think I will have material for a second Netfilter batch in my queue if time allow to make it fit in this merge window. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-31netlink: Introduce nla_strdup()Phil Sutter1-0/+24
This is similar to strdup() for netlink string attributes. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31net netlink: Add new type NLA_BITFIELD32Jamal Hadi Salim1-0/+30
Generic bitflags attribute content sent to the kernel by user. With this netlink attr type the user can either set or unset a flag in the kernel. The value is a bitmap that defines the bit values being set The selector is a bitmask that defines which value bit is to be considered. A check is made to ensure the rules that a kernel subsystem always conforms to bitflags the kernel already knows about. i.e if the user tries to set a bit flag that is not understood then the _it will be rejected_. In the most basic form, the user specifies the attribute policy as: [ATTR_GOO] = { .type = NLA_BITFIELD32, .validation_data = &myvalidflags }, where myvalidflags is the bit mask of the flags the kernel understands. If the user _does not_ provide myvalidflags then the attribute will also be rejected. Examples: value = 0x0, and selector = 0x1 implies we are selecting bit 1 and we want to set its value to 0. value = 0x2, and selector = 0x2 implies we are selecting bit 2 and we want to set its value to 1. Suggested-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20net: manual clean code which call skb_put_[data:zero]yuan linyu1-5/+1
Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16networking: make skb_put & friends return void pointersJohannes Berg1-1/+1
It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions (skb_put, __skb_put and pskb_put) return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_put, __skb_put }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_put, __skb_put }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) which actually doesn't cover pskb_put since there are only three users overall. A handful of stragglers were converted manually, notably a macro in drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many instances in net/bluetooth/hci_sock.c. In the former file, I also had to fix one whitespace problem spatch introduced. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16networking: introduce and use skb_put_data()Johannes Berg1-1/+1
A common pattern with skb_put() is to just want to memcpy() some data into the new space, introduce skb_put_data() for this. An spatch similar to the one for skb_put_zero() converts many of the places using it: @@ identifier p, p2; expression len, skb, data; type t, t2; @@ ( -p = skb_put(skb, len); +p = skb_put_data(skb, data, len); | -p = (t)skb_put(skb, len); +p = skb_put_data(skb, data, len); ) ( p2 = (t2)p; -memcpy(p2, data, len); | -memcpy(p, data, len); ) @@ type t, t2; identifier p, p2; expression skb, data; @@ t *p; ... ( -p = skb_put(skb, sizeof(t)); +p = skb_put_data(skb, data, sizeof(t)); | -p = (t *)skb_put(skb, sizeof(t)); +p = skb_put_data(skb, data, sizeof(t)); ) ( p2 = (t2)p; -memcpy(p2, data, sizeof(*p)); | -memcpy(p, data, sizeof(*p)); ) @@ expression skb, len, data; @@ -memcpy(skb_put(skb, len), data, len); +skb_put_data(skb, data, len); (again, manually post-processed to retain some comments) Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-13networking: use skb_put_zero()Johannes Berg1-2/+1
Use the recently introduced helper to replace the pattern of skb_put() && memset(), this transformation was done with the following spatch: @@ identifier p; expression len; expression skb; @@ -p = skb_put(skb, len); -memset(p, 0, len); +p = skb_put_zero(skb, len); Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-10/+18
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-20netlink: smaller nla_attr_minlen tableAlexey Dobriyan1-1/+1
Length of a netlink attribute may be u16 but lengths of basic attributes are much smaller, so small we can save 16 bytes of .rodata and pocket change inside .text. 16-bit is worse on x86-64 than 8-bit because of operand size override prefix. add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-19 (-19) function old new delta validate_nla 418 417 -1 nla_policy_len 66 64 -2 nla_attr_minlen 32 16 -16 Total: Before=154865051, After=154865032, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-24libnl: fix help of _64bit functionsNicolas Dichtel1-2/+6
Fix typo and describe 'padattr'. Fixes: 089bf1a6a924 ("libnl: add more helpers to align attributes on 64-bit") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>