kernel/linux.git/net/core/lwt_bpf.c, branch linux-5.3.y

net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup

2019-12-18T15:05:50+00:00

[ Upstream commit 6c8991f41546c3c472503dff1ea9daaddf9331c2 ] ipv6_stub uses the ip6_dst_lookup function to allow other modules to perform IPv6 lookups. However, this function skips the XFRM layer entirely. All users of ipv6_stub->ip6_dst_lookup use ip_route_output_flow (via the ip_route_output_key and ip_route_output helpers) for their IPv4 lookups, which calls xfrm_lookup_route(). This patch fixes this inconsistent behavior by switching the stub to ip6_dst_lookup_flow, which also calls xfrm_lookup_route(). This requires some changes in all the callers, as these two functions take different arguments and have different return types. Fixes: 5f81bd2e5d80 ("ipv6: export a stub for IPv6 symbols used by vxlan") Reported-by: Xiumei Mu Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

bpf: lwtunnel: Fix reroute supplying invalid dst

2019-11-12T18:27:33+00:00

[ Upstream commit 9e8acd9c44a0dd52b2922eeb82398c04e356c058 ] The dst in bpf_input() has lwtstate field set. As it is of the LWTUNNEL_ENCAP_BPF type, lwtstate->data is struct bpf_lwt. When the bpf program returns BPF_LWT_REROUTE, ip_route_input_noref is directly called on this skb. This causes invalid memory access, as ip_route_input_slow calls skb_tunnel_info(skb) that expects the dst->lwstate->data to be struct ip_tunnel_info. This results to struct bpf_lwt being accessed as struct ip_tunnel_info. Drop the dst before calling the IP route input functions (both for IPv4 and IPv6). Reported by KASAN. Fixes: 3bd0b15281af ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c") Signed-off-by: Jiri Benc Signed-off-by: Alexei Starovoitov Acked-by: Peter Oskolkov Link: https://lore.kernel.org/bpf/111664d58fe4e9dd9c8014bb3d0b2dab93086a9e.1570609794.git.jbenc@redhat.com Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295

2019-06-05T15:36:38+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 64 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de Signed-off-by: Greg Kroah-Hartman

netlink: make validation more configurable for future strictness

2019-04-27T21:07:21+00:00

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 Signed-off-by: David S. Miller

netlink: make nla_nest_start() add NLA_F_NESTED flag

2019-04-27T21:03:44+00:00

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 Acked-by: Jiri Pirko Acked-by: David Ahern Signed-off-by: David S. Miller

ipv6: Move ipv6 stubs to a separate header file

2019-03-29T17:53:45+00:00

The number of stubs is growing and has nothing to do with addrconf. Move the definition of the stubs to a separate header file and update users. In the move, drop the vxlan specific comment before ipv6_stub. Code move only; no functional change intended. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: fix GSO in bpf_lwt_push_ip_encap

2019-03-07T09:41:29+00:00

GSO needs inner headers and inner protocol set properly to work. skb->inner_mac_header: skb_reset_inner_headers() assigns the current mac header value to inner_mac_header; but it is not set at the point, so we need to call skb_reset_inner_mac_header, otherwise gre_gso_segment fails: it does int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); ... if (unlikely(!pskb_may_pull(skb, tnl_hlen))) ... skb->inner_protocol should also be correctly set. Fixes: ca78801a81e0 ("bpf: handle GSO in bpf_lwt_push_encap") Signed-off-by: Peter Oskolkov Reviewed-by: David Ahern Acked-by: Song Liu Signed-off-by: Daniel Borkmann

net: fix double-free in bpf_lwt_xmit_reroute

2019-02-25T06:24:50+00:00

dst_output() frees skb when it fails (see, for example, ip_finish_output2), so it must not be freed in this case. Fixes: 3bd0b15281af ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c") Signed-off-by: Peter Oskolkov Signed-off-by: David S. Miller

bpf: fix memory leak in bpf_lwt_xmit_reroute

2019-02-14T23:10:06+00:00

On error the skb should be freed. Tested with diff/steps provided by David Ahern. v2: surface routing errors to the user instead of a generic EINVAL, as suggested by David Ahern. Reported-by: David Ahern Fixes: 3bd0b15281af ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c") Signed-off-by: Peter Oskolkov Reviewed-by: David Ahern Signed-off-by: Alexei Starovoitov

bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c

2019-02-14T02:27:55+00:00

This patch builds on top of the previous patch in the patchset, which added BPF_LWT_ENCAP_IP mode to bpf_lwt_push_encap. As the encapping can result in the skb needing to go via a different interface/route/dst, bpf programs can indicate this by returning BPF_LWT_REROUTE, which triggers a new route lookup for the skb. v8 changes: fix kbuild errors when LWTUNNEL_BPF is builtin, but IPV6 is a module: as LWTUNNEL_BPF can only be either Y or N, call IPV6 routing functions only if they are built-in. v9 changes: - fixed a kbuild test robot compiler warning; - call IPV6 routing functions via ipv6_stub. v10 changes: removed unnecessary IS_ENABLED and pr_warn_once. v11 changes: fixed a potential dst leak. Signed-off-by: Peter Oskolkov Signed-off-by: Alexei Starovoitov