kernel/linux.git/include/net/netlink.h, branch v5.10.258

netlink: allow be16 and be32 types in all uint policy checks

2026-04-18T08:31:05+00:00

[ Upstream commit 5fac9b7c16c50c6c7699517f582b56e3743f453a ] __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 Stable-dep-of: 8f15b5071b45 ("netfilter: ctnetlink: use netlink policy range checks") Signed-off-by: Sasha Levin

netlink: introduce bigendian integer types

2026-04-18T08:31:05+00:00

[ Upstream commit ecaf75ffd5f5db320d8b1da0198eef5a5ce64a3f ] 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 Suggested-by: Johannes Berg Signed-off-by: Florian Westphal Link: https://lore.kernel.org/r/20221031123407.9158-1-fw@strlen.de Signed-off-by: Jakub Kicinski Stable-dep-of: 8f15b5071b45 ("netfilter: ctnetlink: use netlink policy range checks") Signed-off-by: Sasha Levin

netlink: hide validation union fields from kdoc

2026-04-18T08:31:05+00:00

[ Upstream commit 7354c9024f2835f6122ed9612e21ab379df050f9 ] 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 Stable-dep-of: 8f15b5071b45 ("netfilter: ctnetlink: use netlink policy range checks") Signed-off-by: Sasha Levin

netlink: introduce NLA_POLICY_MAX_BE

2026-04-18T08:31:05+00:00

[ Upstream commit 08724ef69907214ce622344fe4945412e38368f0 ] 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 Signed-off-by: David S. Miller Stable-dep-of: 8f15b5071b45 ("netfilter: ctnetlink: use netlink policy range checks") Signed-off-by: Sasha Levin

netlink: export policy in extended ACK

2020-10-10T03:22:32+00:00

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 Signed-off-by: Johannes Berg Signed-off-by: Jakub Kicinski

netlink: add mask validation

2020-10-06T13:25:55+00:00

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 Signed-off-by: David S. Miller

netlink: create helpers for checking type is an int

2020-10-06T13:25:55+00:00

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 Signed-off-by: David S. Miller

netlink: rework policy dump to support multiple policies

2020-10-03T21:18:29+00:00

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 Signed-off-by: David S. Miller

genetlink: add a structure for dump state

2020-10-03T02:11:12+00:00

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 Reviewed-by: Johannes Berg Signed-off-by: David S. Miller

netlink: fix policy dump leak

2020-10-02T20:07:42+00:00

[ 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 Reviewed-by: Jakub Kicinski Signed-off-by: David S. Miller