kernel/linux.git/net/mpls, branch v6.6.152

sysctl: treewide: constify ctl_table_header::ctl_table_arg

2026-08-09T18:22:03+00:00

[ Upstream commit bfa858f220ab8c950dd3e1310fee61950d0ecdae ] To be able to constify instances of struct ctl_tables it is necessary to remove ways through which non-const versions are exposed from the sysctl core. One of these is the ctl_table_arg member of struct ctl_table_header. Constify this reference as a prerequisite for the full constification of struct ctl_table instances. No functional change. Signed-off-by: Thomas Weißschuh Reviewed-by: Kees Cook Signed-off-by: David S. Miller Stable-dep-of: f8d5e7846025 ("sctp: avoid auth_enable sysctl UAF during netns teardown") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: mpls: initialize rtm_tos in mpls_getroute()

2026-08-09T18:21:43+00:00

[ Upstream commit 295dd295e2137e10e9a5b1891d97e0f08de76f03 ] mpls_getroute() builds the RTM_NEWROUTE reply to an RTM_GETROUTE request by filling a struct rtmsg allocated from an skb whose data area is not zeroed (alloc_skb(NLMSG_GOODSIZE, ...)). It sets every field of the header except rtm_tos: r = nlmsg_data(nlh); r->rtm_family = AF_MPLS; r->rtm_dst_len = 20; r->rtm_src_len = 0; r->rtm_table = RT_TABLE_MAIN; r->rtm_type = RTN_UNICAST; r->rtm_scope = RT_SCOPE_UNIVERSE; r->rtm_protocol = rt->rt_protocol; r->rtm_flags = 0; struct rtmsg has no padding, so the one uninitialised byte rtm_tos (offset 3) is copied straight to user space on recvmsg(), leaking a byte of uninitialised heap memory. This is in contrast to mpls_dump_route(), which fills the very same header and does set rtm_tos = 0. Initialize rtm_tos to 0, matching mpls_dump_route(). Reproduced with KMSAN by adding an MPLS route and issuing a non-RTM_F_FIB_MATCH RTM_GETROUTE for its label: BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x36c/0x33f0 _copy_to_iter+0x36c/0x33f0 __skb_datagram_iter+0x196/0x12c0 skb_copy_datagram_iter+0x5b/0x210 netlink_recvmsg+0x37b/0xef0 ... Uninit was created at: __alloc_skb+0x8ca/0x10e0 mpls_getroute+0x1280/0x3a40 rtnetlink_rcv_msg+0x1138/0x15a0 ... Byte 19 of 64 is uninitialized (byte 19 = nlmsghdr(16) + rtmsg offset 3 = rtm_tos) Fixes: 397fc9e5cefe ("mpls: route get support") Signed-off-by: Yehyeong Lee Link: https://patch.msgid.link/20260723010830.289917-1-yhlee@isslab.korea.ac.kr Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n

2026-08-03T09:15:16+00:00

[ Upstream commit 56d96fededd61192cd7cc8d2b0f36adfd59036c3 ] On CONFIG_INET=n builds, mpls_valid_fib_dump_req() walks the parsed attribute table itself instead of calling ip_valid_fib_dump_req(). The RTA_OIF arm passes tb[RTA_OIF] to nla_get_u32() without checking it is present, so an RTM_GETROUTE dump for AF_MPLS with strict checking and no RTA_OIF hits a NULL dereference. RTM_GETROUTE is RTNL_KIND_GET, which rtnetlink_rcv_msg() permits without CAP_NET_ADMIN, so an unprivileged user can trigger it. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:mpls_valid_fib_dump_req (net/mpls/af_mpls.c:2189) Call Trace: mpls_dump_routes (net/mpls/af_mpls.c:2236) netlink_dump (net/netlink/af_netlink.c:2331) __netlink_dump_start (net/netlink/af_netlink.c:2446) rtnetlink_rcv_msg (net/core/rtnetlink.c:7033) netlink_rcv_skb (net/netlink/af_netlink.c:2556) netlink_unicast (net/netlink/af_netlink.c:1345) netlink_sendmsg (net/netlink/af_netlink.c:1900) __sock_sendmsg (net/socket.c:790) ____sys_sendmsg (net/socket.c:2684) ___sys_sendmsg (net/socket.c:2738) __sys_sendmsg (net/socket.c:2770) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Skip unset attributes, as ip_valid_fib_dump_req() does. Fixes: 196cfebf8972 ("net/mpls: Handle kernel side filtering of route dumps") Assisted-by: Claude:claude-opus-4-8 Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: David Ahern Link: https://patch.msgid.link/20260711114958.1009619-3-bestswngs@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

mpls: add missing unregister_netdevice_notifier to mpls_init

2026-03-25T10:06:06+00:00

[ Upstream commit 99600f79b28c83c68bae199a3d8e95049a758308 ] If mpls_init() fails after registering mpls_dev_notifier, it never gets removed. Add the missing unregister_netdevice_notifier() call to the error handling path. Fixes: 5be2062e3080 ("mpls: Handle error of rtnl_register_module().") Signed-off-by: Sabrina Dubroca Link: https://patch.msgid.link/7c55363c4f743d19e2306204a134407c90a69bbb.1773228081.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

mpls: Use rcu_dereference_rtnl() in mpls_route_input_rcu().

2025-06-27T10:09:02+00:00

[ Upstream commit 6dbb0d97c5096072c78a6abffe393584e57ae945 ] As syzbot reported [0], mpls_route_input_rcu() can be called from mpls_getroute(), where is under RTNL. net->mpls.platform_label is only updated under RTNL. Let's use rcu_dereference_rtnl() in mpls_route_input_rcu() to silence the splat. [0]: WARNING: suspicious RCU usage 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0 Not tainted ---------------------------- net/mpls/af_mpls.c:84 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz.2.4451/17730: #0: ffffffff9012a3e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9012a3e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:6961 stack backtrace: CPU: 1 UID: 0 PID: 17730 Comm: syz.2.4451 Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 mpls_route_input_rcu+0x1d4/0x200 net/mpls/af_mpls.c:84 mpls_getroute+0x621/0x1ea0 net/mpls/af_mpls.c:2381 rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6964 netlink_rcv_skb+0x16d/0x440 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmmsg+0x200/0x420 net/socket.c:2709 __do_sys_sendmmsg net/socket.c:2736 [inline] __se_sys_sendmmsg net/socket.c:2733 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2733 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0a2818e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0a28f52038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f0a283b5fa0 RCX: 00007f0a2818e969 RDX: 0000000000000003 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f0a28210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0a283b5fa0 R15: 00007ffce5e9f268 Fixes: 0189197f4416 ("mpls: Basic routing support") Reported-by: syzbot+8a583bdd1a5cc0b0e068@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68507981.a70a0220.395abc.01ef.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250616201532.1036568-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv6: introduce dst_rt6_info() helper

2024-12-14T18:59:35+00:00

[ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ] Instead of (struct rt6_info *)dst casts, we can use : #define dst_rt6_info(_ptr) \ container_of_const(_ptr, struct rt6_info, dst) Some places needed missing const qualifiers : ip6_confirm_neigh(), ipv6_anycast_destination(), ipv6_unicast_destination(), has_gateway() v2: added missing parts (David Ahern) Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: 3301ab7d5aeb ("net/ipv6: release expired exception dst cached in socket") Signed-off-by: Sasha Levin

mpls: Handle error of rtnl_register_module().

2024-10-17T13:24:30+00:00

[ Upstream commit 5be2062e3080e3ff6707816caa445ec0c6eaacf7 ] Since introduced, mpls_init() has been ignoring the returned value of rtnl_register_module(), which could fail silently. Handling the error allows users to view a module as an all-or-nothing thing in terms of the rtnetlink functionality. This prevents syzkaller from reporting spurious errors from its tests, where OOM often occurs and module is automatically loaded. Let's handle the errors by rtnl_register_many(). Fixes: 03c0566542f4 ("mpls: Netlink commands to add, remove, and dump routes") Signed-off-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

mpls: no longer hold RTNL in mpls_netconf_dump_devconf()

2024-10-17T13:24:29+00:00

[ Upstream commit e0f89d2864b062b027196925ea19f94b2ce50d6a ] - Use for_each_netdev_dump() to no longer rely on net->dev_index_head hash table. - No longer care of net->dev_base_seq - Fix return value at the end of a dump, so that NLMSG_DONE can be appended to current skb, saving one recvmsg() system call. - No longer grab RTNL, RCU protection is enough, afer adding one READ_ONCE(mdev->input_enabled) in mpls_netconf_fill_devconf() Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20240410111951.2673193-1-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 5be2062e3080 ("mpls: Handle error of rtnl_register_module().") Signed-off-by: Sasha Levin

net: mpls: error out if inner headers are not set

2024-04-13T11:07:41+00:00

commit 025f8ad20f2e3264d11683aa9cbbf0083eefbdcd upstream. mpls_gso_segment() assumes skb_inner_network_header() returns a valid result: mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb); if (unlikely(!mpls_hlen || mpls_hlen % MPLS_HLEN)) goto out; if (unlikely(!pskb_may_pull(skb, mpls_hlen))) With syzbot reproducer, skb_inner_network_header() yields 0, skb_network_header() returns 108, so this will "pskb_may_pull(skb, -108)))" which triggers a newly added DEBUG_NET_WARN_ON_ONCE() check: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5068 at include/linux/skbuff.h:2723 pskb_may_pull_reason include/linux/skbuff.h:2723 [inline] WARNING: CPU: 0 PID: 5068 at include/linux/skbuff.h:2723 pskb_may_pull include/linux/skbuff.h:2739 [inline] WARNING: CPU: 0 PID: 5068 at include/linux/skbuff.h:2723 mpls_gso_segment+0x773/0xaa0 net/mpls/mpls_gso.c:34 [..] skb_mac_gso_segment+0x383/0x740 net/core/gso.c:53 nsh_gso_segment+0x40a/0xad0 net/nsh/nsh.c:108 skb_mac_gso_segment+0x383/0x740 net/core/gso.c:53 __skb_gso_segment+0x324/0x4c0 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] [..] sch_direct_xmit+0x11a/0x5f0 net/sched/sch_generic.c:327 [..] packet_sendmsg+0x46a9/0x6130 net/packet/af_packet.c:3113 [..] First iteration of this patch made mpls_hlen signed and changed test to error out to "mpls_hlen <= 0 || ..". Eric Dumazet said: > I was thinking about adding a debug check in skb_inner_network_header() > if inner_network_header is zero (that would mean it is not 'set' yet), > but this would trigger even after your patch. So add new skb_inner_network_header_was_set() helper and use that. The syzbot reproducer injects data via packet socket. The skb that gets allocated and passed down the stack has ->protocol set to NSH (0x894f) and gso_type set to SKB_GSO_UDP | SKB_GSO_DODGY. This gets passed to skb_mac_gso_segment(), which sees NSH as ptype to find a callback for. nsh_gso_segment() retrieves next type: proto = tun_p_to_eth_p(nsh_hdr(skb)->np); ... which is MPLS (TUN_P_MPLS_UC). It updates skb->protocol and then calls mpls_gso_segment(). Inner offsets are all 0, so mpls_gso_segment() ends up with a negative header size. In case more callers rely on silent handling of such large may_pull values we could also 'legalize' this behaviour, either replacing the debug check with (len > INT_MAX) test or removing it and instead adding a comment before existing if (unlikely(len > skb->len)) return SKB_DROP_REASON_PKT_TOO_SMALL; test in pskb_may_pull_reason(), saying that this check also implicitly takes care of callers that miscompute header sizes. Cc: Simon Horman Fixes: 219eee9c0d16 ("net: skbuff: add overflow debug check to pull/push helpers") Reported-by: syzbot+99d15fcdb0132a1e1a82@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/00000000000043b1310611e388aa@google.com/raw Signed-off-by: Florian Westphal Link: https://lore.kernel.org/r/20240222140321.14080-1-fw@strlen.de Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

networking: Update to register_net_sysctl_sz

2023-08-15T22:26:18+00:00

Move from register_net_sysctl to register_net_sysctl_sz for all the networking related files. Do this while making sure to mirror the NULL assignments with a table_size of zero for the unprivileged users. We need to move to the new function in preparation for when we change SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do so would erroneously allow ARRAY_SIZE() to be called on a pointer. We hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all the relevant net sysctl registering functions to register_net_sysctl_sz in subsequent commits. An additional size function was added to the following files in order to calculate the size of an array that is defined in another file: include/net/ipv6.h net/ipv6/icmp.c net/ipv6/route.c net/ipv6/sysctl_net_ipv6.c Signed-off-by: Joel Granados Signed-off-by: Luis Chamberlain