Fix the lwtunnel_output() reentry loop in ioam6_iptunnel when the
destination is the same after transformation. Note that a check on the
destination address was already performed, but it was not enough. This
is the example of a lwtunnel user taking care of loops without relying
only on the last resort detection offered by lwtunnel.
Fixes: 8cb3bf8bff ("ipv6: ioam: Add support for the ip6ip6 encapsulation")
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250314120048.12569-3-justin.iurman@uliege.be
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
While creating a new IPv6, we could get a weird -ENOMEM when
RTA_NH_ID is set and either of the conditions below is true:
1) CONFIG_IPV6_SUBTREES is enabled and rtm_src_len is specified
2) nexthop_get() fails
e.g.)
# strace ip -6 route add fe80::dead:beef:dead:beef nhid 1 from ::
recvmsg(3, {msg_iov=[{iov_base=[...[
{error=-ENOMEM, msg=[... [...]]},
[{nla_len=49, nla_type=NLMSGERR_ATTR_MSG}, "Nexthops can not be used with so"...]
]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 148
Let's set err explicitly after ip_fib_metrics_init() in
ip6_route_info_create().
Fixes: f88d8ea67f ("ipv6: Plumb support for nexthop object in a fib6_info")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250312013854.61125-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
fib_check_nh_v6_gw() expects that fib6_nh_init() cleans up everything
when it fails.
Commit 7dd73168e2 ("ipv6: Always allocate pcpu memory in a fib6_nh")
moved fib_nh_common_init() before alloc_percpu_gfp() within fib6_nh_init()
but forgot to add cleanup for fib6_nh->nh_common.nhc_pcpu_rth_output in
case it fails to allocate fib6_nh->rt6i_pcpu, resulting in memleak.
Let's call fib_nh_common_release() and clear nhc_pcpu_rth_output in the
error path.
Note that we can remove the fib6_nh_release() call in nh_create_ipv6()
later in net-next.git.
Fixes: 7dd73168e2 ("ipv6: Always allocate pcpu memory in a fib6_nh")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250312010333.56001-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Use addrconf_addr_gen() to generate IPv6 link-local addresses on GRE
devices in most cases and fall back to using add_v4_addrs() only in
case the GRE configuration is incompatible with addrconf_addr_gen().
GRE used to use addrconf_addr_gen() until commit e5dd729460
("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL
address") restricted this use to gretap and ip6gretap devices, and
created add_v4_addrs() (borrowed from SIT) for non-Ethernet GRE ones.
The original problem came when commit 9af28511be ("addrconf: refuse
isatap eui64 for INADDR_ANY") made __ipv6_isatap_ifid() fail when its
addr parameter was 0. The commit says that this would create an invalid
address, however, I couldn't find any RFC saying that the generated
interface identifier would be wrong. Anyway, since gre over IPv4
devices pass their local tunnel address to __ipv6_isatap_ifid(), that
commit broke their IPv6 link-local address generation when the local
address was unspecified.
Then commit e5dd729460 ("ip/ip6_gre: use the same logic as SIT
interfaces when computing v6LL address") tried to fix that case by
defining add_v4_addrs() and calling it to generate the IPv6 link-local
address instead of using addrconf_addr_gen() (apart for gretap and
ip6gretap devices, which would still use the regular
addrconf_addr_gen(), since they have a MAC address).
That broke several use cases because add_v4_addrs() isn't properly
integrated into the rest of IPv6 Neighbor Discovery code. Several of
these shortcomings have been fixed over time, but add_v4_addrs()
remains broken on several aspects. In particular, it doesn't send any
Router Sollicitations, so the SLAAC process doesn't start until the
interface receives a Router Advertisement. Also, add_v4_addrs() mostly
ignores the address generation mode of the interface
(/proc/sys/net/ipv6/conf/*/addr_gen_mode), thus breaking the
IN6_ADDR_GEN_MODE_RANDOM and IN6_ADDR_GEN_MODE_STABLE_PRIVACY cases.
Fix the situation by using add_v4_addrs() only in the specific scenario
where the normal method would fail. That is, for interfaces that have
all of the following characteristics:
* run over IPv4,
* transport IP packets directly, not Ethernet (that is, not gretap
interfaces),
* tunnel endpoint is INADDR_ANY (that is, 0),
* device address generation mode is EUI64.
In all other cases, revert back to the regular addrconf_addr_gen().
Also, remove the special case for ip6gre interfaces in add_v4_addrs(),
since ip6gre devices now always use addrconf_addr_gen() instead.
Fixes: e5dd729460 ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/559c32ce5c9976b269e6337ac9abb6a96abe5096.1741375285.git.gnault@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
mld_newpack() can be called without RTNL or RCU being held.
Note that we no longer can use sock_alloc_send_skb() because
ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.
Instead use alloc_skb() and charge the net->ipv6.igmp_sk
socket under RCU protection.
Fixes: b8ad0cbc58 ("[NETNS][IPV6] mcast - handle several network namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250212141021.1663666-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
igmp6_send() can be called without RTNL or RCU being held.
Extend RCU protection so that we can safely fetch the net pointer
and avoid a potential UAF.
Note that we no longer can use sock_alloc_send_skb() because
ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.
Instead use alloc_skb() and charge the net->ipv6.igmp_sk
socket under RCU protection.
Fixes: b8ad0cbc58 ("[NETNS][IPV6] mcast - handle several network namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
icmp6_send() must acquire rcu_read_lock() sooner to ensure
the dev_net() call done from a safe context.
Other ICMPv6 uses of dev_net() seem safe, change them to
dev_net_rcu() to get LOCKDEP support to catch bugs.
Fixes: 9a43b709a2 ("[NETNS][IPV6] icmp6 - make icmpv6_socket per namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-12-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 4094871db1 ("udp: only do GSO if # of segs > 1") avoided GSO
for small packets. But the kernel currently dismisses GSO requests only
after checking MTU/PMTU on gso_size. This means any packets, regardless
of their payload sizes, could be dropped when PMTU becomes smaller than
requested gso_size. We encountered this issue in production and it
caused a reliability problem that new QUIC connection cannot be
established before PMTU cache expired, while non GSO sockets still
worked fine at the same time.
Ideally, do not check any GSO related constraints when payload size is
smaller than requested gso_size, and return EMSGSIZE instead of EINVAL
on MTU/PMTU check failure to be more specific on the error cause.
Fixes: 4094871db1 ("udp: only do GSO if # of segs > 1")
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some lwtunnels have a dst cache for post-transformation dst.
If the packet destination did not change we may end up recording
a reference to the lwtunnel in its own cache, and the lwtunnel
state will never be freed.
Discovered by the ioam6.sh test, kmemleak was recently fixed
to catch per-cpu memory leaks. I'm not sure if rpl and seg6
can actually hit this, but in principle I don't see why not.
Fixes: 8cb3bf8bff ("ipv6: ioam: Add support for the ip6ip6 encapsulation")
Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Fixes: a7a29f9c36 ("net: ipv6: add rpl sr tunnel")
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250130031519.2716843-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Steffen Klassert says:
====================
pull request (net): ipsec 2025-01-27
1) Fix incrementing the upper 32 bit sequence numbers for GSO skbs.
From Jianbo Liu.
2) Fix an out-of-bounds read on xfrm state lookup.
From Florian Westphal.
3) Fix secpath handling on packet offload mode.
From Alexandre Cassen.
4) Fix the usage of skb->sk in the xfrm layer.
5) Don't disable preemption while looking up cache state
to fix PREEMPT_RT.
From Sebastian Sewior.
* tag 'ipsec-2025-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
xfrm: Don't disable preemption while looking up cache state.
xfrm: Fix the usage of skb->sk
xfrm: delete intermediate secpath entry in packet offload mode
xfrm: state: fix out-of-bounds read during lookup
xfrm: replay: Fix the update of replay_esn->oseq_hi for GSO
====================
Link: https://patch.msgid.link/20250127060757.3946314-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
inet6_addr_add() and inet6_addr_modify() have the same code to validate
IPv6 lifetime that is done under RTNL.
Let's factorise it out to inet6_rtm_newaddr() so that we can validate
the lifetime without RTNL later.
Note that inet6_addr_add() is called from addrconf_add_ifaddr(), but the
lifetime is INFINITY_LIFE_TIME in the path, so expires and flags are 0.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115080608.28127-10-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
