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2023-12-19genetlink: introduce helpers to do filtered multicastJiri Pirko
Currently it is possible for netlink kernel user to pass custom filter function to broadcast send function netlink_broadcast_filtered(). However, this is not exposed to multicast send and to generic netlink users. Extend the api and introduce a netlink helper nlmsg_multicast_filtered() and a generic netlink helper genlmsg_multicast_netns_filtered() to allow generic netlink families to specify filter function while sending multicast messages. Signed-off-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-12-08netlink: Return unsigned value for nla_len()Kees Cook
The return value from nla_len() is never expected to be negative, and can never be more than struct nlattr::nla_len (a u16). Adjust the prototype on the function. This will let GCC's value range optimization passes know that the return can never be negative, and can never be larger than u16. As recently discussed[1], this silences the following warning in GCC 12+: net/wireless/nl80211.c: In function 'nl80211_set_cqm_rssi.isra': net/wireless/nl80211.c:12892:17: warning: 'memcpy' specified bound 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=] 12892 | memcpy(cqm_config->rssi_thresholds, thresholds, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 12893 | flex_array_size(cqm_config, rssi_thresholds, | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 12894 | n_thresholds)); | ~~~~~~~~~~~~~~ A future change would be to clamp the subtraction to make sure it never wraps around if nla_len is somehow less than NLA_HDRLEN, which would have the additional benefit of being defensive in the face of nlattr corruption or logic errors. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202311090752.hWcJWAHL-lkp@intel.com/ [1] Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jeff Johnson <quic_jjohnson@quicinc.com> Cc: Michael Walle <mwalle@kernel.org> Cc: Max Schulze <max.schulze@online.de> Link: https://lore.kernel.org/r/20231202202539.it.704-kees@kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20231206205904.make.018-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-18rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlinkLi RongQing
if a PF has 256 or more VFs, ip link command will allocate an order 3 memory or more, and maybe trigger OOM due to memory fragment, the VFs needed memory size is computed in rtnl_vfinfo_size. so introduce nlmsg_new_large which calls netlink_alloc_large_skb in which vmalloc is used for large memory, to avoid the failure of allocating memory ip invoked oom-killer: gfp_mask=0xc2cc0(GFP_KERNEL|__GFP_NOWARN|\ __GFP_COMP|__GFP_NOMEMALLOC), order=3, oom_score_adj=0 CPU: 74 PID: 204414 Comm: ip Kdump: loaded Tainted: P OE Call Trace: dump_stack+0x57/0x6a dump_header+0x4a/0x210 oom_kill_process+0xe4/0x140 out_of_memory+0x3e8/0x790 __alloc_pages_slowpath.constprop.116+0x953/0xc50 __alloc_pages_nodemask+0x2af/0x310 kmalloc_large_node+0x38/0xf0 __kmalloc_node_track_caller+0x417/0x4d0 __kmalloc_reserve.isra.61+0x2e/0x80 __alloc_skb+0x82/0x1c0 rtnl_getlink+0x24f/0x370 rtnetlink_rcv_msg+0x12c/0x350 netlink_rcv_skb+0x50/0x100 netlink_unicast+0x1b2/0x280 netlink_sendmsg+0x355/0x4a0 sock_sendmsg+0x5b/0x60 ____sys_sendmsg+0x1ea/0x250 ___sys_sendmsg+0x88/0xd0 __sys_sendmsg+0x5e/0xa0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f95a65a5b70 Cc: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Link: https://lore.kernel.org/r/20231115120108.3711-1-lirongqing@baidu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-26netlink: make range pointers in policies constJakub Kicinski
struct nla_policy is usually constant itself, but unless we make the ranges inside constant we won't be able to make range structs const. The ranges are not modified by the core. Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231025162204.132528-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-20netlink: add variable-length / auto integersJakub Kicinski
We currently push everyone to use padding to align 64b values in netlink. Un-padded nla_put_u64() doesn't even exist any more. The story behind this possibly start with this thread: https://lore.kernel.org/netdev/20121204.130914.1457976839967676240.davem@davemloft.net/ where DaveM was concerned about the alignment of a structure containing 64b stats. If user space tries to access such struct directly: struct some_stats *stats = nla_data(attr); printf("A: %llu", stats->a); lack of alignment may become problematic for some architectures. These days we most often put every single member in a separate attribute, meaning that the code above would use a helper like nla_get_u64(), which can deal with alignment internally. Even for arches which don't have good unaligned access - access aligned to 4B should be pretty efficient. Kernel and well known libraries deal with unaligned input already. Padded 64b is quite space-inefficient (64b + pad means at worst 16B per attr vs 32b which takes 8B). It is also more typing: if (nla_put_u64_pad(rsp, NETDEV_A_SOMETHING_SOMETHING, value, NETDEV_A_SOMETHING_PAD)) Create a new attribute type which will use 32 bits at netlink level if value is small enough (probably most of the time?), and (4B-aligned) 64 bits otherwise. Kernel API is just: if (nla_put_uint(rsp, NETDEV_A_SOMETHING_SOMETHING, value)) Calling this new type "just" sint / uint with no specific size will hopefully also make people more comfortable with using it. Currently telling people "don't use u8, you may need the bits, and netlink will round up to 4B, anyway" is the #1 comment we give to newcomers. In terms of netlink layout it looks like this: 0 4 8 12 16 32b: [nlattr][ u32 ] 64b: [ pad ][nlattr][ u64 ] uint(32) [nlattr][ u32 ] uint(64) [nlattr][ u64 ] Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-27netlink: allow be16 and be32 types in all uint policy checksFlorian Westphal
__NLA_IS_BEINT_TYPE(tp) isn't useful. NLA_BE16/32 are identical to NLA_U16/32, the only difference is that it tells the netlink validation functions that byteorder conversion might be needed before comparing the value to the policy min/max ones. After this change all policy macros that can be used with UINT types, such as NLA_POLICY_MASK() can also be used with NLA_BE16/32. This will be used to validate nf_tables flag attributes which are in bigendian byte order. Signed-off-by: Florian Westphal <fw@strlen.de>
2023-01-28net: netlink: recommend policy range validationJohannes Berg
For large ranges (outside of s16) the documentation currently recommends open-coding the validation, but it's better to use the NLA_POLICY_FULL_RANGE() or NLA_POLICY_FULL_RANGE_SIGNED() policy validation instead; recommend that. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20230127084506.09f280619d64.I5dece85f06efa8ab0f474ca77df9e26d3553d4ab@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-01netlink: introduce bigendian integer typesFlorian Westphal
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>
2022-10-31rtnetlink: pass netlink message header and portid to rtnl_configure_link()Hangbin Liu
This patch pass netlink message header and portid to rtnl_configure_link() All the functions in this call chain need to add the parameters so we can use them in the last call rtnl_notify(), and notify the userspace about the new link info if NLM_F_ECHO flag is set. - rtnl_configure_link() - __dev_notify_flags() - rtmsg_ifinfo() - rtmsg_ifinfo_event() - rtmsg_ifinfo_build_skb() - rtmsg_ifinfo_send() - rtnl_notify() Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub suggested. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-31netlink: split up copies in the ack constructionJakub Kicinski
Clean up the use of unsafe_memcpy() by adding a flexible array at the end of netlink message header and splitting up the header and data copies. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-28netlink: hide validation union fields from kdocJakub Kicinski
Mark the validation fields as private, users shouldn't set them directly and they are too complicated to explain in a more succinct way (there's already a long explanation in the comment above). The strict_start_type field is set directly and has a dedicated comment so move that above the "private" section. Link: https://lore.kernel.org/r/20221027212107.2639255-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-07netlink: introduce NLA_POLICY_MAX_BEFlorian Westphal
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>
2022-08-24netlink: fix some kernel-doc commentsZhengchao Shao
Modify the comment of input parameter of nlmsg_ and nla_ function. Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Link: https://lore.kernel.org/r/20220824013621.365103-1-shaozhengchao@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-27net: netlink: add the case when nlh is NULLYajun Deng
Add the case when nlh is NULL in nlmsg_report(), so that the caller doesn't need to deal with this case. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-11-16treewide: rename nla_strlcpy to nla_strscpy.Francis Laniel
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 Laniel
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 Berg
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 Kicinski
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 Kicinski
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 Berg
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 Kicinski
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 Berg
[ 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. Miller
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 Dichtel
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 Berg
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 Berg
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 Berg
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 Berg
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 Berg
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 Berg
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 Berg
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 Pirko
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 Kubecek
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 Ahern
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 Schimmel
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 Schimmel
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 Berg
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 Kubecek
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 Berg
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 Berg
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 Berg
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 Berg
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 Kubecek
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 Berg
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 Berg
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 Ahern
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 Ahern
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. Miller
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 Berg
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>
generated by cgit (git 2.34.1) at 2024-05-27 22:16:48 +0000