linux.git/net/mpls, branch v7.2 Linux kernel source tree net: mpls: initialize rtm_tos in mpls_getroute() 2026-07-28T09:06:06+00:00 Yehyeong Lee yhlee@isslab.korea.ac.kr 2026-07-23T01:08:29+00:00 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 <yhlee@isslab.korea.ac.kr> Link: https://patch.msgid.link/20260723010830.289917-1-yhlee@isslab.korea.ac.kr Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
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 <yhlee@isslab.korea.ac.kr>
Link: https://patch.msgid.link/20260723010830.289917-1-yhlee@isslab.korea.ac.kr
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
mpls: Set rt->rt_nhn just before returning from mpls_nh_build_multi(). 2026-07-23T11:36:46+00:00 Kuniyuki Iwashima kuniyu@google.com 2026-07-16T17:06:07+00:00 3671f0419d90b98a02f313830595ab958c8b2025 Commit f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.") added change_nexthops() loop to call netdev_put() for the nexthop devices before freeing mpls_route. Then, mpls_nh_build_multi() was also changed to avoid iterating uninitialised nexthops in mpls_rt_free_rcu(). However, setting rt->rt_nhn to 0 at the entry of mpls_nh_build_multi() makes the following change_nexthops() no-op. Let's set rt->rt_nhn just before returning from mpls_nh_build_multi(). Fixes: f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.") Reported-by: Anthony Doeraene <anthony.doeraene@uclouvain.be> Closes: https://lore.kernel.org/netdev/036a0c95-f5d4-46ab-88e7-1eab567d7a84@uclouvain.be/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260716170609.804629-1-kuniyu@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
Commit f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.") added
change_nexthops() loop to call netdev_put() for the nexthop devices
before freeing mpls_route.

Then, mpls_nh_build_multi() was also changed to avoid iterating
uninitialised nexthops in mpls_rt_free_rcu().

However, setting rt->rt_nhn to 0 at the entry of mpls_nh_build_multi()
makes the following change_nexthops() no-op.

Let's set rt->rt_nhn just before returning from mpls_nh_build_multi().

Fixes: f0914b8436c5 ("mpls: Hold dev refcnt for mpls_nh.")
Reported-by: Anthony Doeraene <anthony.doeraene@uclouvain.be>
Closes: https://lore.kernel.org/netdev/036a0c95-f5d4-46ab-88e7-1eab567d7a84@uclouvain.be/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260716170609.804629-1-kuniyu@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n 2026-07-17T11:20:38+00:00 Weiming Shi bestswngs@gmail.com 2026-07-11T11:50:00+00:00 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 <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260711114958.1009619-3-bestswngs@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
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 <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260711114958.1009619-3-bestswngs@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: Remove rtnl_held of struct fib_dump_filter. 2026-06-09T00:06:23+00:00 Kuniyuki Iwashima kuniyu@google.com 2026-06-04T22:46:25+00:00 a543cb49e603f88917e3258bbcb59a60d9c3c2fa Commit 22e36ea9f5d7 ("inet: allow ip_valid_fib_dump_req() to be called with RTNL or RCU") introduced the rtnl_held field in struct fib_dump_filter to switch __dev_get_by_index() and dev_get_by_index_rcu() depending on the caller's context. This field served as an interim measure while we were incrementally converting all callers of ip_valid_fib_dump_req() to RCU. Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have been converted to RCU, the field is no longer necessary. Let's remove it. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260604224712.3209821-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Commit 22e36ea9f5d7 ("inet: allow ip_valid_fib_dump_req() to
be called with RTNL or RCU") introduced the rtnl_held field in
struct fib_dump_filter to switch __dev_get_by_index() and
dev_get_by_index_rcu() depending on the caller's context.

This field served as an interim measure while we were incrementally
converting all callers of ip_valid_fib_dump_req() to RCU.

Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have
been converted to RCU, the field is no longer necessary.

Let's remove it.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-8-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-04-02T18:03:13+00:00 Jakub Kicinski kuba@kernel.org 2026-04-02T17:57:09+00:00 8ffb33d7709b59ff60560f48960a73bd8a55be95 Cross-merge networking fixes after downstream PR (net-7.0-rc7). Conflicts: net/vmw_vsock/af_vsock.c b18c83388874 ("vsock: initialize child_ns_mode_locked in vsock_net_init()") 0de607dc4fd8 ("vsock: add G2H fallback for CIDs not owned by H2G transport") Adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c ceee35e5674a ("bnxt_en: Refactor some basic ring setup and adjustment logic") 57cdfe0dc70b ("bnxt_en: Resize RSS contexts on channel count change") drivers/net/wireless/intel/iwlwifi/mld/mac80211.c 4d56037a02bd ("wifi: iwlwifi: mld: block EMLSR during TDLS connections") 687a95d204e7 ("wifi: iwlwifi: mld: correctly set wifi generation data") drivers/net/wireless/intel/iwlwifi/mld/scan.h b6045c899e37 ("wifi: iwlwifi: mld: Refactor scan command handling") ec66ec6a5a8f ("wifi: iwlwifi: mld: Fix MLO scan timing") drivers/net/wireless/intel/iwlwifi/mvm/fw.c 078df640ef05 ("wifi: iwlwifi: mld: add support for iwl_mcc_allowed_ap_type_cmd v 2") 323156c3541e ("wifi: iwlwifi: mvm: don't send a 6E related command when not supported") Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Cross-merge networking fixes after downstream PR (net-7.0-rc7).

Conflicts:

net/vmw_vsock/af_vsock.c
  b18c83388874 ("vsock: initialize child_ns_mode_locked in vsock_net_init()")
  0de607dc4fd8 ("vsock: add G2H fallback for CIDs not owned by H2G transport")

Adjacent changes:

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
  ceee35e5674a ("bnxt_en: Refactor some basic ring setup and adjustment logic")
  57cdfe0dc70b ("bnxt_en: Resize RSS contexts on channel count change")

drivers/net/wireless/intel/iwlwifi/mld/mac80211.c
  4d56037a02bd ("wifi: iwlwifi: mld: block EMLSR during TDLS connections")
  687a95d204e7 ("wifi: iwlwifi: mld: correctly set wifi generation data")

drivers/net/wireless/intel/iwlwifi/mld/scan.h
  b6045c899e37 ("wifi: iwlwifi: mld: Refactor scan command handling")
  ec66ec6a5a8f ("wifi: iwlwifi: mld: Fix MLO scan timing")

drivers/net/wireless/intel/iwlwifi/mvm/fw.c
  078df640ef05 ("wifi: iwlwifi: mld: add support for iwl_mcc_allowed_ap_type_cmd v
2")
  323156c3541e ("wifi: iwlwifi: mvm: don't send a 6E related command when not supported")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: convert remaining ipv6_stub users to direct function calls 2026-03-29T18:21:23+00:00 Fernando Fernandez Mancera fmancera@suse.de 2026-03-25T12:08:49+00:00 d76f6b170a10414a9c674b6db4bd0473b1b30050 As IPv6 is built-in only, the ipv6_stub infrastructure is no longer necessary. Convert remaining ipv6_stub users to make direct function calls. The fallback functions introduced previously will prevent linkage errors when CONFIG_IPV6 is disabled. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Link: https://patch.msgid.link/20260325120928.15848-9-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As IPv6 is built-in only, the ipv6_stub infrastructure is no longer
necessary.

Convert remaining ipv6_stub users to make direct function calls. The
fallback functions introduced previously will prevent linkage errors
when CONFIG_IPV6 is disabled.

Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://patch.msgid.link/20260325120928.15848-9-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mpls: add seqcount to protect the platform_label{,s} pair 2026-03-27T01:32:14+00:00 Sabrina Dubroca sd@queasysnail.net 2026-03-23T23:25:57+00:00 629ec78ef8608d955ce217880cdc3e1873af3a15 The RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have an inconsistent view of platform_labels vs platform_label in case of a concurrent resize (resize_platform_label_table, under platform_mutex). This can lead to OOB accesses. This patch adds a seqcount, so that we get a consistent snapshot. Note that mpls_label_ok is also susceptible to this, so the check against RTA_DST in rtm_to_route_config, done outside platform_mutex, is not sufficient. This value gets passed to mpls_label_ok once more in both mpls_route_add and mpls_route_del, so there is no issue, but that additional check must not be removed. Reported-by: Yuan Tan <tanyuan98@outlook.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Fixes: 7720c01f3f590 ("mpls: Add a sysctl to control the size of the mpls label table") Fixes: dde1b38e873c ("mpls: Convert mpls_dump_routes() to RCU.") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/cd8fca15e3eb7e212b094064cd83652e20fd9d31.1774284088.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
The RCU-protected codepaths (mpls_forward, mpls_dump_routes) can have
an inconsistent view of platform_labels vs platform_label in case of a
concurrent resize (resize_platform_label_table, under
platform_mutex). This can lead to OOB accesses.

This patch adds a seqcount, so that we get a consistent snapshot.

Note that mpls_label_ok is also susceptible to this, so the check
against RTA_DST in rtm_to_route_config, done outside platform_mutex,
is not sufficient. This value gets passed to mpls_label_ok once more
in both mpls_route_add and mpls_route_del, so there is no issue, but
that additional check must not be removed.

Reported-by: Yuan Tan <tanyuan98@outlook.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Fixes: 7720c01f3f590 ("mpls: Add a sysctl to control the size of the mpls label table")
Fixes: dde1b38e873c ("mpls: Convert mpls_dump_routes() to RCU.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/cd8fca15e3eb7e212b094064cd83652e20fd9d31.1774284088.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-03-19T21:16:00+00:00 Jakub Kicinski kuba@kernel.org 2026-03-12T19:53:34+00:00 edab1ca5ec6fffecbf340e26956ce73e502901d5 Cross-merge networking fixes after downstream PR (net-7.0-rc5). net/netfilter/nft_set_rbtree.c 598adea720b97 ("netfilter: revert nft_set_rbtree: validate open interval overlap") 3aea466a43998 ("netfilter: nft_set_rbtree: don't disable bh when acquiring tree lock") https://lore.kernel.org/abgaQBpeGstdN4oq@sirena.org.uk No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Cross-merge networking fixes after downstream PR (net-7.0-rc5).

net/netfilter/nft_set_rbtree.c
  598adea720b97 ("netfilter: revert nft_set_rbtree: validate open interval overlap")
  3aea466a43998 ("netfilter: nft_set_rbtree: don't disable bh when acquiring tree lock")
https://lore.kernel.org/abgaQBpeGstdN4oq@sirena.org.uk

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mpls: add missing unregister_netdevice_notifier to mpls_init 2026-03-13T02:25:59+00:00 Sabrina Dubroca sd@queasysnail.net 2026-03-11T22:35:09+00:00 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 <sd@queasysnail.net> Link: https://patch.msgid.link/7c55363c4f743d19e2306204a134407c90a69bbb.1773228081.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
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 <sd@queasysnail.net>
Link: https://patch.msgid.link/7c55363c4f743d19e2306204a134407c90a69bbb.1773228081.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mpls: remove test against ipv6_stub 2026-03-03T02:48:43+00:00 Eric Dumazet edumazet@google.com 2026-02-28T17:57:15+00:00 a0e8c9a5060fbdb72fca767164467a3cf2b8fc30 ipv6_stub is never NULL, let's remove this test. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260228175715.1195536-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
ipv6_stub is never NULL, let's remove this test.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260228175715.1195536-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>