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2020-11-16treewide: rename nla_strlcpy to nla_strscpy.Francis Laniel1-2/+2
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 Laniel1-1/+1
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>
2020-10-09netlink: export policy in extended ACKJohannes Berg1-0/+4
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/+10
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>
2020-10-06netlink: create helpers for checking type is an intJakub Kicinski1-8/+9
There's a number of policies which check if type is a uint or sint. Factor the checking against the list of value sizes to a helper for easier reuse. v2: - new patch Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03netlink: rework policy dump to support multiple policiesJohannes Berg1-3/+6
Rework the policy dump code a bit to support adding multiple policies to a single dump, in order to e.g. support per-op policies in generic netlink. v2: - move kernel-doc to implementation [Jakub] - squash the first patch to not flip-flop on the prototype [Jakub] - merge netlink_policy_dump_get_policy_idx() with the old get_policy_idx() we already had - rebase without Jakub's patch to have per-op dump Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: add a structure for dump stateJakub Kicinski1-4/+7
Whenever netlink dump uses more than 2 cb->args[] entries code gets hard to read. We're about to add more state to ctrl_dumppolicy() so create a structure. Since the structure is typed and clearly named we can remove the local fam_id variable and use ctx->fam_id directly. v3: - rebase onto explicit free fix v1: - s/nl_policy_dump/netlink_policy_dump_state/ - forward declare struct netlink_policy_dump_state, and move from passing unsigned long to actual pointer type - add build bug on - u16 fam_id - s/args/ctx/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02netlink: fix policy dump leakJohannes Berg1-1/+2
[ Upstream commit a95bc734e60449e7b073ff7ff70c35083b290ae9 ] If userspace doesn't complete the policy dump, we leak the allocated state. Fix this. Fixes: d07dcf9aadd6 ("netlink: add infrastructure to expose policies to userspace") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-2/+0
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10netlink: fix doc about nlmsg_parse/nla_validateNicolas Dichtel1-2/+0
There is no @validate argument. CC: Johannes Berg <johannes.berg@intel.com> Fixes: 3de644035446 ("netlink: re-add parse/validate functions in strict mode") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18netlink: make NLA_BINARY validation more flexibleJohannes Berg1-27/+31
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>
2020-04-30netlink: add infrastructure to expose policies to userspaceJohannes Berg1-0/+6
Add, and use in generic netlink, helpers to dump out a netlink policy to userspace, including all the range validation data, nested policies etc. This lets userspace discover what the kernel understands. For families/commands other than generic netlink, the helpers need to be used directly in an appropriate command, or we can add some infrastructure (a new netlink family) that those can register their policies with for introspection. I'm not that familiar with non-generic netlink, so that's left out for now. The data exposed to userspace also includes min and max length for binary/string data, I've done that instead of letting the userspace tools figure out whether min/max is intended based on the type so that we can extend this later in the kernel, we might want to just use the range data for example. Because of this, I opted to not directly expose the NLA_* values, even if some of them are already exposed via BPF, as with min/max length we don't need to have different types here for NLA_BINARY/NLA_MIN_LEN/NLA_EXACT_LEN, we just make them all NL_ATTR_TYPE_BINARY with min/max length optionally set. Similarly, we don't really need NLA_MSECS, and perhaps can remove it in the future - but not if we encode it into the userspace API now. It gets mapped to NL_ATTR_TYPE_U64 here. Note that the exposing here corresponds to the strict policy interpretation, and NLA_UNSPEC items are omitted entirely. To get those, change them to NLA_MIN_LEN which behaves in exactly the same way, but is exposed. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30netlink: factor out policy range helpersJohannes Berg1-0/+5
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>
2020-04-30netlink: remove NLA_EXACT_LEN_WARNJohannes Berg1-7/+8
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>
2020-04-30netlink: allow NLA_MSECS to have range validationJohannes Berg1-2/+4
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>
2020-04-30netlink: extend policy range validationJohannes Berg1-0/+45
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>
2020-04-30netlink: remove type-unsafe validation_data pointerJohannes Berg1-28/+32
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>
2020-03-30net: introduce nla_put_bitfield32() helper and use itJiri Pirko1-0/+15
Introduce a helper to pass value and selector to. The helper packs them into struct and puts them into netlink message. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-12netlink: rename nl80211_validate_nested() to nla_validate_nested()Michal Kubecek1-4/+4
Function nl80211_validate_nested() is not specific to nl80211, it's a counterpart to nla_validate_nested_deprecated() with strict validation. For consistency with other validation and parse functions, rename it to nla_validate_nested(). Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-13netlink: Fix nlmsg_parse as a wrapper for strict message parsingDavid Ahern1-3/+2
Eric reported a syzbot warning: BUG: KMSAN: uninit-value in nh_valid_get_del_req+0x6f1/0x8c0 net/ipv4/nexthop.c:1510 CPU: 0 PID: 11812 Comm: syz-executor444 Not tainted 5.3.0-rc3+ #17 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294 nh_valid_get_del_req+0x6f1/0x8c0 net/ipv4/nexthop.c:1510 rtm_del_nexthop+0x1b1/0x610 net/ipv4/nexthop.c:1543 rtnetlink_rcv_msg+0x115a/0x1580 net/core/rtnetlink.c:5223 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5241 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0xf6c/0x1050 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x110f/0x1330 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] ___sys_sendmsg+0x14ff/0x1590 net/socket.c:2311 __sys_sendmmsg+0x53a/0xae0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2439 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2439 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x63/0xe7 The root cause is nlmsg_parse calling __nla_parse which means the header struct size is not checked. nlmsg_parse should be a wrapper around __nlmsg_parse with NL_VALIDATE_STRICT for the validate argument very much like nlmsg_parse_deprecated is for NL_VALIDATE_LIBERAL. Fixes: 3de6440354465 ("netlink: re-add parse/validate functions in strict mode") Reported-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-06-18netlink: Add field to skip in-kernel notificationsIdo Schimmel1-1/+3
The struct includes a 'skip_notify' flag that indicates if netlink notifications to user space should be suppressed. As explained in commit 3b1137fe7482 ("net: ipv6: Change notifications for multipath add to RTA_MULTIPATH"), this is useful to suppress per-nexthop RTM_NEWROUTE notifications when an IPv6 multipath route is added / deleted. Instead, one notification is sent for the entire multipath route. This concept is also useful for in-kernel notifications. Sending one in-kernel notification for the addition / deletion of an IPv6 multipath route - instead of one per-nexthop - provides a significant increase in the insertion / deletion rate to underlying devices. Add a 'skip_notify_kernel' flag to suppress in-kernel notifications. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-18netlink: Document all fields of 'struct nl_info'Ido Schimmel1-0/+2
Some fields were not documented. Add documentation. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14nl80211: require and validate vendor command policyJohannes Berg1-0/+9
Require that each vendor command give a policy of its sub-attributes in NL80211_ATTR_VENDOR_DATA, and then (stricly) check the contents, including the NLA_F_NESTED flag that we couldn't check on the outer layer because there we don't know yet. It is possible to use VENDOR_CMD_RAW_DATA for raw data, but then no nested data can be given (NLA_F_NESTED flag must be clear) and the data is just passed as is to the command. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-05-04netlink: add validation of NLA_F_NESTED flagMichal Kubecek1-1/+10
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>
2019-04-27netlink: add strict parsing for future attributesJohannes Berg1-0/+18
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>
2019-04-27netlink: re-add parse/validate functions in strict modeJohannes Berg1-0/+87
This re-adds the parse and validate functions like nla_parse() that are now actually strict after the previous rename and were just split out to make sure everything is converted (and if not compilation of the previous patch would fail.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27netlink: make validation more configurable for future strictnessJohannes Berg1-47/+191
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>
2019-04-27netlink: add NLA_MIN_LENJohannes Berg1-1/+5
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>
2019-04-27netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek1-3/+23
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-01netlink: reduce NLA_POLICY_NESTED{,_ARRAY} argumentsJohannes Berg1-2/+6
In typical cases, there's no need to pass both the maxattr and the policy array pointer, as the maxattr should just be ARRAY_SIZE(policy) - 1. Therefore, to be less error prone, just remove the maxattr argument from the default macros and deduce the size accordingly. Leave the original macros with a leading underscore to use here and in case somebody needs to pass a policy pointer where the policy isn't declared in the same place and thus ARRAY_SIZE() cannot be used. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-10-12netlink: replace __NLA_ENSURE implementationJohannes Berg1-1/+1
We already have BUILD_BUG_ON_ZERO() which I just hadn't found before, so we should use it here instead of open-coding another implementation thereof. 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 Ahern1-0/+17
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>
2018-10-08netlink: Add extack message to nlmsg_parse for invalid header lengthDavid Ahern1-1/+3
Give a user a reason why EINVAL is returned in nlmsg_parse. Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Christian Brauner <christian@brauner.io> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+1
Minor conflict in net/core/rtnetlink.c, David Ahern's bug fix in 'net' overlapped the renaming of a netlink attribute in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01netlink: add validation function to policyJohannes Berg1-1/+23
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>
2018-10-01netlink: add attribute range validation to policyJohannes Berg1-3/+64
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>
2018-09-29netlink: fix typo in nla_parse_nested() commentJohannes Berg1-1/+1
Fix a simple typo: attribuets -> attributes 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 Berg1-1/+11
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 Berg1-2/+11
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: make validation_data constJohannes Berg1-1/+1
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 Berg1-2/+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>
2018-09-18netlink: add ethernet address policy typesJohannes Berg1-0/+13
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>
2018-09-18netlink: add NLA_REJECT policy typeJohannes Berg1-1/+12
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>
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>
2017-09-25netlink: fix nla_put_{u8,u16,u32} for KASANArnd Bergmann1-18/+55
When CONFIG_KASAN is enabled, the "--param asan-stack=1" causes rather large stack frames in some functions. This goes unnoticed normally because CONFIG_FRAME_WARN is disabled with CONFIG_KASAN by default as of commit 3f181b4d8652 ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y"). The kernelci.org build bot however has the warning enabled and that led me to investigate it a little further, as every build produces these warnings: net/wireless/nl80211.c:4389:1: warning: the frame size of 2240 bytes is larger than 2048 bytes [-Wframe-larger-than=] net/wireless/nl80211.c:1895:1: warning: the frame size of 3776 bytes is larger than 2048 bytes [-Wframe-larger-than=] net/wireless/nl80211.c:1410:1: warning: the frame size of 2208 bytes is larger than 2048 bytes [-Wframe-larger-than=] net/bridge/br_netlink.c:1282:1: warning: the frame size of 2544 bytes is larger than 2048 bytes [-Wframe-larger-than=] Most of this problem is now solved in gcc-8, which can consolidate the stack slots for the inline function arguments. On older compilers we can add a workaround by declaring a local variable in each function to pass the inline function argument. Cc: stable@vger.kernel.org Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-0/+1
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/+1
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>
2017-07-30net netlink: Add new type NLA_BITFIELD32Jamal Hadi Salim1-0/+16
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>
2017-07-13netlink: correctly document nla_put_u64_64bit()Rolf Eike Beer1-2/+2
Signed-off-by: Rolf Eike Beer <eb@emlix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-10/+23
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>
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