rt6_route_rcv() validates the Route Information option (RFC 4191) length
against the prefix length, but both checks are off by one.
rinfo->length is the ND option length in units of 8 octets and it
*includes* the 8-byte option header, so an option carrying N bytes of
prefix has length == 1 + N/8. RFC 4191 section 2.3 requires length 3
when Prefix Length is greater than 64, and 2 or 3 when it is greater
than 0. The code accepts length >= 2 and length >= 1 respectively.
ipv6_addr_prefix() then copies prefix_len/8 bytes out of rinfo->prefix,
so a Router Advertisement with (prefix_len=128, length=2) or
(prefix_len=64, length=1) makes the kernel read up to 8 bytes past the
end of the option. Those bytes end up in the prefix of the route that
gets installed, so they are visible to userspace:
# RA with a Route Information option (prefix_len=128, length=2)
# followed by a source link-layer address option, 01 01 de ad be ef ca fe
$ ip -6 route show
2001:db8:dead:beef:101:dead:beef:cafe via fe80::1234 dev veth0 proto ra
^^^^^^^^^^^^^^^^^^ the next option, read out of bounds
When the Route Information option is the last one in the packet, those
eight bytes come from the skb tail room instead.
Reject the option lengths RFC 4191 does not allow.
Fixes: 70ceb4f539 ("[IPV6]: ROUTE: Add experimental support for Route Information Option in RA (RFC4191).")
Cc: stable@vger.kernel.org
Signed-off-by: Yuejie Shi <syjcnss@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260730035310.74584-1-syjcnss@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since the call to __ip6_del_rt_siblings has been converted under
rcu read lock and it only has one call point
we should no longer block or yield.
Our stack trace from the syzbot reproducer looks as follows:
__ip6_del_rt_siblings
rtnl_notify (Here we pass gfp_any() -> GFP_KERNEL)
nlmsg_notify
nlmsg_multicast
nlmsg_multicast_filtered
netlink_broadcast_filtered (GFP_KERNEL passed from earlier)
netlink_broadcast_filtered can yield if GFP_KERNEL
is passed, which we do not want to happen.
Fix this by changing the allocation flag of rtnl_notify.
Also change the flag passed to nlmsg_new. Even though it
is not related to the syzbot generated bug it still falls
under the same requirements.
Reported-by: syzbot+84d4a405ed798b40c96d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=84d4a405ed798b40c96d
Fixes: bd11ff421d ("ipv6: Get rid of RTNL for SIOCDELRT and RTM_DELROUTE.")
Signed-off-by: Nikola Z. Ivanov <zlatistiv@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260719105759.558050-1-zlatistiv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib6_nh_mtu_change() re-fetches idev via __in6_dev_get(arg->dev) and
dereferences idev->cnf.mtu6 without a NULL check. addrconf_ifdown()
clears dev->ip6_ptr with RCU_INIT_POINTER() after rt6_disable_ip() has
released tb6_lock, so the RA-driven MTU walk can observe a NULL idev and
oops. The caller rt6_mtu_change_route() guards its own __in6_dev_get(),
but this re-fetch is unguarded; nexthop-backed routes survive
addrconf_ifdown()'s flush, so the walk still reaches it after ip6_ptr is
nulled.
Return 0 when idev is NULL, matching rt6_mtu_change_route() and the
fib6_mtu() fix in commit 5ad509c1fd ("ipv6: Fix null-ptr-deref in
fib6_mtu().").
Oops: general protection fault, ... KASAN: null-ptr-deref in range
[0x00000000000002a8-0x00000000000002af]
RIP: 0010:fib6_nh_mtu_change+0x203/0x990
rt6_mtu_change_route+0x141/0x1d0
__fib6_clean_all+0xd0/0x160
rt6_mtu_change+0xb4/0x100
ndisc_router_discovery+0x24b5/0x2cb0
icmpv6_rcv+0x12e9/0x1710
ipv6_rcv+0x39b/0x410
Fixes: c0b220cf7d ("ipv6: Refactor exception functions")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260619045334.2427073-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge in late fixes in preparation for the net-next PR.
Conflicts:
net/tls/tls_sw.c
406e8a651a ("net: skmsg: preserve sg.copy across SG transforms")
79511603a6 ("tls: remove dead sockmap (psock) handling from the SW path")
drivers/net/ethernet/microsoft/mana/mana_en.c
f8fd56977e ("net: mana: guard TX wq object destroy with INVALID_MANA_HANDLE check")
d07efe5a6e ("net: mana: Use per-queue allocation for tx_qp to reduce allocation size")
https://lore.kernel.org/ajAPXu-C_PuTgV-a@sirena.org.uk
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When MTU is large, ip6_default_advmss() can return IPV6_MAXPLEN (65535).
This is interpreted by TCP as mss_clamp, allowing the MSS to reach 65535.
However, 0xFFFF is also used as a magic value GSO_BY_FRAGS in the kernel.
If a TCP packet with gso_size=0xFFFF is passed to skb_segment(), it will
be mistakenly treated as GSO_BY_FRAGS, leading to a NULL pointer
dereference because local TCP packets do not use frag_list.
Fix this by returning min(IPV6_MAXPLEN, GSO_BY_FRAGS - 1) (65534) from
ip6_default_advmss() when MTU is large.
Also update the stale comment in ip6_default_advmss() which suggested
that IPV6_MAXPLEN is returned to mean "any MSS".
Fixes: 3953c46c3a ("sk_buff: allow segmenting based on frag sizes")
Reported-by: syzbot+ebdb22d461c904fc3cb2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a2c3193.8812e0fc.3c3fa4.0001.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612162517.83394-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 741a11d9e4 ("net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is
set") made the kernel honor the oif parameter when specified as part of
output route lookup:
# ip route add 2001:db8:1::/64 dev dummy1
# ip route add ::/0 dev dummy2
# ip route get 2001:db8:1::1 oif dummy2 fibmatch
default dev dummy2 metric 1024 pref medium
Due to regression reports, the behavior was partially reverted in commit
d46a9d678e ("net: ipv6: Dont add RT6_LOOKUP_F_IFACE flag if saddr
set") to only honor the oif if source address is not specified:
# ip route get 2001:db8:1::1 from 2001:db8:2::1 oif dummy2 fibmatch
2001:db8:1::/64 dev dummy1 metric 1024 pref medium
That is, when source address is specified, the kernel will choose the
most specific route even if its nexthop device does not match the
specified oif.
This creates a problem for multipath routes. After looking up a route,
when source address is not specified, the kernel will choose a nexthop
whose nexthop device matches the specified oif:
# sysctl -wq net.ipv6.conf.all.forwarding=1
# ip route add 2001:db8:10::/64 nexthop via fe80::1 dev dummy1 nexthop via fe80::2 dev dummy2
# for i in {1..100}; do ip route get 2001:db8:10::${i} oif dummy2; done | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
But will disregard the oif when source address is specified despite the
fact that a matching nexthop exists:
# for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy2; done | grep -o dummy[0-9] | sort | uniq -c
53 dummy1
47 dummy2
This behavior differs from IPv4:
# ip address add 192.0.2.1/32 dev lo
# ip route add 198.51.100.0/24 nexthop via inet6 fe80::1 dev dummy1 nexthop via inet6 fe80::2 dev dummy2
# for i in {1..100}; do ip route get 198.51.100.${i} from 192.0.2.1 oif dummy2; done | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
What happens is that fib6_table_lookup() returns a route with a matching
nexthop device (assuming it exists):
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy2; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
But it is later overwritten during path selection in fib6_select_path()
which instead chooses a nexthop according to the calculated hash.
Solve this by telling fib6_select_path() to skip path selection if we
have an oif match during output route lookup (iif being
LOOPBACK_IFINDEX).
Behavior after the change:
# sysctl -wq net.ipv6.conf.all.forwarding=1
# ip route add 2001:db8:10::/64 nexthop via fe80::1 dev dummy1 nexthop via fe80::2 dev dummy2
# for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy2; done | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
Note that enabling forwarding is only needed because we did not add
neighbor entries for the gateway addresses. When forwarding is disabled
and CONFIG_IPV6_ROUTER_PREF is not enabled in kernel config, the kernel
will treat non-existing neighbor entries as errors and perform
round-robin between the nexthops:
# sysctl -wq net.ipv6.conf.all.forwarding=0
# for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy2; done | grep -o dummy[0-9] | sort | uniq -c
50 dummy1
50 dummy2
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260611154605.992528-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, when using multipath routes without nexthop objects,
fib6_table_lookup() selects the nexthop with the highest score. This
means that when both a source address and an oif are specified, the
nexthop that is chosen is the one that matches in terms of oif:
# sysctl -wq net.ipv6.conf.all.forwarding=1
# ip address add 2001:db8:2::1/64 dev lo
# ip route add 2001:db8:10::/64 nexthop via fe80::1 dev dummy1 nexthop via fe80::2 dev dummy2
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy1; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy1
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:10::${i} from 2001:db8:2::1 oif dummy2; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
When using nexthop objects, fib6_table_lookup() selects the first
matching nexthop and not necessarily the one with the highest score:
# ip nexthop add id 1 via fe80::1 dev dummy1
# ip nexthop add id 2 via fe80::2 dev dummy2
# ip nexthop add id 3 group 1/2
# ip route add 2001:db8:20::/64 nhid 3
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:20::${i} from 2001:db8:2::1 oif dummy1; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy1
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:20::${i} from 2001:db8:2::1 oif dummy2; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy1
This is not very significant right now because the nexthop is later
overwritten during path selection in fib6_select_path(). However, the
next patch is going to skip path selection when we have an oif match
during output route lookup.
As a preparation for this change, align the nexthop object behavior with
the legacy one and make sure that fib6_table_lookup() always selects the
best matching nexthop. Do that by always returning 0 from
rt6_nh_find_match() in order not to terminate the loop in
nexthop_for_each_fib6_nh() and storing in arg->nh the best matching
nexthop so far.
Behavior after the change:
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:20::${i} from 2001:db8:2::1 oif dummy1; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy1
# perf record -e fib6:fib6_table_lookup -- bash -c "for i in {1..100}; do ip route get 2001:db8:20::${i} from 2001:db8:2::1 oif dummy2; done > /dev/null"
# perf script | grep -o dummy[0-9] | sort | uniq -c
100 dummy2
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260611154605.992528-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
These symbols don't need to be exported, they are only used from vmlinux:
- inet6addr_notifier_call_chain
- inet6addr_validator_notifier_call_chain
- in6addr_linklocal_allnodes
- in6addr_linklocal_allrouters
- in6addr_interfacelocal_allnodes
- in6addr_interfacelocal_allrouters
- in6addr_sitelocal_allrouters
- inet6_cleanup_sock
- ip6_sk_dst_lookup_flow
- ipv6_proxy_select_ident
- ip6_sk_update_pmtu
- ip6_sk_redirect
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260604174555.2801532-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Found while auditing the same pattern Sashiko reported in
rt6_fill_node() [1]. Apply the same fix as
commit f8d8ce1b51 ("ipv6: fix possible infinite loop in fib6_info_uses_dev()").
Writers holding tb6_lock can list_del_rcu(&first->fib6_siblings)
without waiting for RCU readers; first->fib6_siblings.next then
still points into the old ring and this softirq-side walker never
reaches &first->fib6_siblings as its terminator. fib6_purge_rt()
always WRITE_ONCE()s first->fib6_nsiblings to 0 before
list_del_rcu(), so an inside-loop check is a reliable detach signal.
[1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260527053133.180695-2-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Sashiko reported this issue [1]. Apply the same fix as
commit f8d8ce1b51 ("ipv6: fix possible infinite loop in fib6_info_uses_dev()").
Writers holding tb6_lock can list_del_rcu(&rt->fib6_siblings)
without waiting for RCU readers; rt->fib6_siblings.next then still
points into the old ring and this softirq-side walker never reaches
&rt->fib6_siblings, causing a CPU stall. fib6_del_route() always
WRITE_ONCE()s rt->fib6_nsiblings to 0 before list_del_rcu(), so an
inside-loop check is a reliable detach signal.
[1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260527053133.180695-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ip6_route_init() registers ip6_route_dev_notifier before registering the
IPv6 route BPF iterator target. If bpf_iter_register() fails after the
notifier has been registered, the error path currently jumps to
out_register_late_subsys and unwinds the RTNL handlers and pernet route
state without removing the notifier from the netdevice notifier chain.
This leaves ip6_route_dev_notify() callable after the IPv6 route state it
uses has been torn down. Add a separate unwind label for the BPF iterator
failure path and unregister the netdevice notifier before continuing with
the existing cleanup.
Fixes: 138d0be35b ("net: bpf: Add netlink and ipv6_route bpf_iter targets")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260520030329.1061183-1-dbgh9129@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When using IPv6 ECMP routes, if a netdev listed as a nexthop experiences
a carrier change event (e.g., a bond device generating a NETDEV_CHANGE
event after its slaves go linkdown), established connections utilizing
that nexthop fail to fail over to other available nexthops. Instead,
these connections stall or drop.
This happens because the IPv6 FIB code does not invalidate the socket's
cached destination when a NETDEV_CHANGE event occurs. While
fib6_ifdown() correctly marks the nexthop with RTNH_F_LINKDOWN, it
leaves the route's serial number unchanged. As a result, sockets with a
previously cached dst do not realize the route is no longer viable and
continue to try using the non-functional nexthop.
This behavior contrasts with IPv4, which actively flushes cached
destinations on a NETDEV_CHANGE event (see fib_netdev_event() in
net/ipv4/fib_frontend.c).
Fix this by updating the route serial number in fib6_ifdown() when
setting RTNH_F_LINKDOWN. This invalidates stale cached destinations,
forcing sockets to perform a new route lookup and fail over to a
functioning nexthop.
Fixes: 51ebd31815 ("ipv6: add support of equal cost multipath (ECMP)")
Signed-off-by: Sagarika Sharma <sharmasagarika@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260430200909.527827-2-sharmasagarika@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In preparation for dropping ipv6_stub and converting its users to direct
function calls, introduce static inline dummy functions and fallback
macros in the IPv6 networking headers. In addition, introduce checks on
fib6_nh_init(), ip6_dst_lookup_flow() and ip6_fragment() to avoid a
crash due to ipv6.disable=1 set during booting. The other functions are
safe as they cannot be called with ipv6.disable=1 set.
These fallbacks ensure that when CONFIG_IPV6 is completely disabled,
there are no compiling or linking errors due to code paths not guarded
by preprocessor macro IS_ENABLED(CONFIG_IPV6).
In addition, export ndisc_send_na(), ip6_route_input() and
ip6_fragment().
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://patch.msgid.link/20260325120928.15848-6-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As IPv6 is built-in only, it does not make sense to continue using
IS_BUILTIN(CONFIG_IPV6). Therefore, replace it with IS_ENABLED() when
necessary and drop it if it isn't valid anymore.
Notice that there is still one instance related to ICMPv6, as it
requires more changes it will be handle separately.
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20260325120928.15848-4-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The cited commit mechanically put fib6_remove_gc_list()
just after every fib6_clean_expires() call.
When a temporary route is promoted to a permanent route,
there may already be exception routes tied to it.
If fib6_remove_gc_list() removes the route from tb6_gc_hlist,
such exception routes will no longer be aged.
Let's replace fib6_remove_gc_list() with a new helper
fib6_may_remove_gc_list() and use fib6_age_exceptions() there.
Note that net->ipv6 is only compiled when CONFIG_IPV6 is
enabled, so fib6_{add,remove,may_remove}_gc_list() are guarded.
Fixes: 5eb902b8e7 ("net/ipv6: Remove expired routes with a separated list of routes.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260320072317.2561779-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a standalone IPv6 nexthop object is created with a loopback device
(e.g., "ip -6 nexthop add id 100 dev lo"), fib6_nh_init() misclassifies
it as a reject route. This is because nexthop objects have no destination
prefix (fc_dst=::), causing fib6_is_reject() to match any loopback
nexthop. The reject path skips fib_nh_common_init(), leaving
nhc_pcpu_rth_output unallocated. If an IPv4 route later references this
nexthop, __mkroute_output() dereferences NULL nhc_pcpu_rth_output and
panics.
Simplify the check in fib6_nh_init() to only match explicit reject
routes (RTF_REJECT) instead of using fib6_is_reject(). The loopback
promotion heuristic in fib6_is_reject() is handled separately by
ip6_route_info_create_nh(). After this change, the three cases behave
as follows:
1. Explicit reject route ("ip -6 route add unreachable 2001:db8::/64"):
RTF_REJECT is set, enters reject path, skips fib_nh_common_init().
No behavior change.
2. Implicit loopback reject route ("ip -6 route add 2001:db8::/32 dev lo"):
RTF_REJECT is not set, takes normal path, fib_nh_common_init() is
called. ip6_route_info_create_nh() still promotes it to reject
afterward. nhc_pcpu_rth_output is allocated but unused, which is
harmless.
3. Standalone nexthop object ("ip -6 nexthop add id 100 dev lo"):
RTF_REJECT is not set, takes normal path, fib_nh_common_init() is
called. nhc_pcpu_rth_output is properly allocated, fixing the crash
when IPv4 routes reference this nexthop.
Suggested-by: Ido Schimmel <idosch@nvidia.com>
Fixes: 493ced1ac4 ("ipv4: Allow routes to use nexthop objects")
Reported-by: syzbot+334190e097a98a1b81bb@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/698f8482.a70a0220.2c38d7.00ca.GAE@google.com/T/
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260304113817.294966-2-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
l3mdev_master_dev_rcu() can return NULL when the slave device is being
un-slaved from a VRF. All other callers deal with this, but we lost
the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu()
with commit 4832c30d54 ("net: ipv6: put host and anycast routes on
device with address").
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)
Call Trace:
ip6_pol_route (net/ipv6/route.c:2318)
fib6_rule_lookup (net/ipv6/fib6_rules.c:115)
ip6_route_output_flags (net/ipv6/route.c:2607)
vrf_process_v6_outbound (drivers/net/vrf.c:437)
I was tempted to rework the un-slaving code to clear the flag first
and insert synchronize_rcu() before we remove the upper. But looks like
the explicit fallback to loopback_dev is an established pattern.
And I guess avoiding the synchronize_rcu() is nice, too.
Fixes: 4832c30d54 ("net: ipv6: put host and anycast routes on device with address")
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260301194548.927324-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
When we expect an IPv6 dst, use dst6_mtu() instead of dst_mtu()
to save some code space.
Due to current dst6_mtu() implementation, only convert
users in IPv6 stack.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260130210303.3888261-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sysctls are read while their values can change,
add READ_ONCE() annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260115094141.3124990-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IPv4 allows for a nexthop device mismatch when the "onlink" keyword is
specified:
# ip link add name dummy1 up type dummy
# ip address add 192.0.2.1/24 dev dummy1
# ip link add name dummy2 up type dummy
# ip route add 198.51.100.0/24 nexthop via 192.0.2.2 dev dummy2
Error: Nexthop has invalid gateway.
# ip route add 198.51.100.0/24 nexthop via 192.0.2.2 dev dummy2 onlink
# echo $?
0
This seems to be consistent with the description of "onlink" in the
ip-route man page: "Pretend that the nexthop is directly attached to
this link, even if it does not match any interface prefix".
On the other hand, IPv6 rejects a nexthop device mismatch, even when
"onlink" is specified:
# ip link add name dummy1 up type dummy
# ip address add 2001:db8:1::1/64 dev dummy1
# ip link add name dummy2 up type dummy
# ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2
RTNETLINK answers: No route to host
# ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
Error: Nexthop has invalid gateway or device mismatch.
This is intentional according to commit fc1e64e109 ("net/ipv6: Add
support for onlink flag") which added IPv6 "onlink" support and states
that "any unicast gateway is allowed as long as the gateway is not a
local address and if it resolves it must match the given device".
The condition was later relaxed in commit 4ed591c8ab ("net/ipv6: Allow
onlink routes to have a device mismatch if it is the default route") to
allow for a nexthop device mismatch if the gateway address is resolved
via the default route:
# ip link add name dummy1 up type dummy
# ip route add ::/0 dev dummy1
# ip link add name dummy2 up type dummy
# ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2
RTNETLINK answers: No route to host
# ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
# echo $?
0
While the decision to forbid a nexthop device mismatch in IPv6 seems to
be intentional, it is unclear why it was made. Especially when it
differs from IPv4 and seems to go against the intended behavior of
"onlink".
Therefore, relax the condition further and allow for a nexthop device
mismatch when "onlink" is specified:
# ip link add name dummy1 up type dummy
# ip address add 2001:db8:1::1/64 dev dummy1
# ip link add name dummy2 up type dummy
# ip route add 2001:db8:10::/64 nexthop via 2001:db8:1::2 dev dummy2 onlink
# echo $?
0
The motivating use case is the fact that FRR would like to be able to
configure overlay routes of the following form:
# ip route add <host-Z> vrf <VRF> encap ip id <ID> src <VTEP-A> dst <VTEP-Z> via <VTEP-Z> dev vxlan0 onlink
Where vxlan0 is in the default VRF in which "VTEP-Z" is reachable via
one of the underlay routes (e.g., via swpX). Without this patch, the
above only works with IPv4, but not with IPv6.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260111120813.159799-5-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the
current task can be preempted. Another task running on the same CPU
may then execute rt6_make_pcpu_route() and successfully install a
pcpu_rt entry. When the first task resumes execution, its cmpxchg()
in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer
NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding
mdelay() after rt6_get_pcpu_route().
Using preempt_disable/enable is not appropriate here because
ip6_rt_pcpu_alloc() may sleep.
Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:
free our allocation and return the existing pcpu_rt installed by
another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT
kernels where such races should not occur.
Link: https://syzkaller.appspot.com/bug?extid=9b35e9bc0951140d13e6
Fixes: d2d6422f8b ("x86: Allow to enable PREEMPT_RT.")
Reported-by: syzbot+9b35e9bc0951140d13e6@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6918cd88.050a0220.1c914e.0045.GAE@google.com/T/
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20251223051413.124687-1-jiayuan.chen@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ipv6_pinfo.daddr_cache is either NULL or &sk->sk_v6_daddr
We do not need 8 bytes, a boolean is enough.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250916160951.541279-3-edumazet@google.com
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ipv6_pinfo.saddr_cache is either NULL or &np->saddr.
We do not need 8 bytes, a boolean is enough.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250916160951.541279-2-edumazet@google.com
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Refactor icmpv6_xrlim_allow() and ip6_dst_hoplimit()
so that we acquire rcu_read_lock() a bit longer
to be able to use dst_dev_rcu() instead of dst_dev().
__ip6_rt_update_pmtu() and rt6_do_redirect can directly
use dst_dev_rcu() in sections already holding rcu_read_lock().
Small changes to use dst_dev_net_rcu() in
ip6_default_advmss(), ipv6_sock_ac_join(),
ip6_mc_find_dev() and ndisc_send_skb().
Fixes: 4a6ce2b6f2 ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250828195823.3958522-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
Merge in late fixes to prepare for the 6.17 net-next PR.
Conflicts:
net/core/neighbour.c
1bbb76a899 ("neighbour: Fix null-ptr-deref in neigh_flush_dev().")
13a936bb99 ("neighbour: Protect tbl->phash_buckets[] with a dedicated mutex.")
03dc03fa04 ("neighbor: Add NTF_EXT_VALIDATED flag for externally validated entries")
Adjacent changes:
drivers/net/usb/usbnet.c
0d9cfc9b8c ("net: usbnet: Avoid potential RCU stall on LINK_CHANGE event")
2c04d279e8 ("net: usb: Convert tasklet API to new bottom half workqueue mechanism")
net/ipv6/route.c
31d7d67ba1 ("ipv6: annotate data-races around rt->fib6_nsiblings")
1caf272972 ("ipv6: adopt dst_dev() helper")
3b3ccf9ed0 ("net: Remove unnecessary NULL check for lwtunnel_fill_encap()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rt->fib6_nsiblings can be read locklessly, add corresponding
READ_ONCE() and WRITE_ONCE() annotations.
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250725140725.3626540-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib6_info_uses_dev() seems to rely on RCU without an explicit
protection.
Like the prior fix in rt6_nlmsg_size(),
we need to make sure fib6_del_route() or fib6_add_rt2node()
have not removed the anchor from the list, or we risk an infinite loop.
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250725140725.3626540-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While testing prior patch, I was able to trigger
an infinite loop in rt6_nlmsg_size() in the following place:
list_for_each_entry_rcu(sibling, &f6i->fib6_siblings,
fib6_siblings) {
rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
}
This is because fib6_del_route() and fib6_add_rt2node()
uses list_del_rcu(), which can confuse rcu readers,
because they might no longer see the head of the list.
Restart the loop if f6i->fib6_nsiblings is zero.
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250725140725.3626540-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use the new helpers as a step to deal with potential dst->dev races.
v2: fix typo in ipv6_rthdr_rcv() (kernel test robot <lkp@intel.com>)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-10-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use the new helper as a step to deal with potential dst->dev races.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(dst_entry)->lastuse is read and written locklessly,
add corresponding annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(dst_entry)->expires is read and written locklessly,
add corresponding annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
lwtunnel_fill_encap() has NULL check and return 0, so no need
to check before call it.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250624140015.3929241-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sk->sk_uid can be read while another thread changes its
value in sockfs_setattr().
Add sk_uid(const struct sock *sk) helper to factorize the needed
READ_ONCE() annotations, and add corresponding WRITE_ONCE()
where needed.
Fixes: 86741ec254 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Multicast routing is today handled in the input path. Locally generated MC
packets don't hit the IPMR code today. Thus if a VXLAN remote address is
multicast, the driver needs to set an OIF during route lookup. Thus MC
routing configuration needs to be kept in sync with the VXLAN FDB and MDB.
Ideally, the VXLAN packets would be routed by the MC routing code instead.
To that end, this patch adds support to route locally generated multicast
packets. The newly-added routines do largely what ip6_mr_input() and
ip6_mr_forward() do: make an MR cache lookup to find where to send the
packets, and use ip6_output() to send each of them. When no cache entry is
found, the packet is punted to the daemon for resolution.
Similarly to the IPv4 case in a previous patch, the new logic is contingent
on a newly-added IP6CB flag being set.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/3bcc034a3ab4d3c291072fff38f78d7fbbeef4e6.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
These two commits preallocated two per-cpu variables in
ip6_route_info_create() as fib_nh_common_init() and fib6_nh_init()
were expected to be called under RCU.
* commit d27b9c40db ("ipv6: Preallocate nhc_pcpu_rth_output in
ip6_route_info_create().")
* commit 5720a328c3 ("ipv6: Preallocate rt->fib6_nh->rt6i_pcpu in
ip6_route_info_create().")
Now these functions can be called without RCU and can use GFP_KERNEL.
Let's revert the commits.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since commit c4837b9853 ("ipv6: Split ip6_route_info_create()."),
ip6_route_info_create_nh() uses GFP_ATOMIC as it was expected to be
called under RCU.
Now, we can call it without RCU and use GFP_KERNEL.
Let's pass gfp_flags to ip6_route_info_create_nh().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 71c0efb6d1 ("ipv6: Factorise ip6_route_multipath_add().") split
a loop in ip6_route_multipath_add() so that we can put rcu_read_lock()
between ip6_route_info_create() and ip6_route_info_create_nh().
We no longer need to do so as ip6_route_info_create_nh() does not require
RCU now.
Let's revert the commit to simplify the code.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 169fd62799 ("ipv6: Get rid of RTNL for SIOCADDRT and
RTM_NEWROUTE.") added rcu_read_lock() covering
ip6_route_info_create_nh() and __ip6_ins_rt() to guarantee that
nexthop and netdev will not go away.
However, as reported by syzkaller [0], ip_tun_build_state() calls
dst_cache_init() with GFP_KERNEL during the RCU critical section.
ip6_route_info_create_nh() fetches nexthop or netdev depending on
whether RTA_NH_ID is set, and struct fib6_info holds a refcount
of either of them by nexthop_get() or netdev_get_by_index().
netdev_get_by_index() looks up a dev and calls dev_hold() under RCU.
So, we need RCU only around nexthop_find_by_id() and nexthop_get()
( and a few more nexthop code).
Let's add rcu_read_lock() there and remove rcu_read_lock() in
ip6_route_add() and ip6_route_multipath_add().
Now these functions called from fib6_add() need RCU:
- inet6_rt_notify()
- fib6_drop_pcpu_from() (via fib6_purge_rt())
- rt6_flush_exceptions() (via fib6_purge_rt())
- ip6_ignore_linkdown() (via rt6_multipath_rebalance())
All callers of inet6_rt_notify() need RCU, so rcu_read_lock() is
added there.
[0]:
[ BUG: Invalid wait context ]
6.15.0-rc4-syzkaller-00746-g836b313a14a3 #0 Tainted: G W
----------------------------
syz-executor234/5832 is trying to lock:
ffffffff8e021688 (pcpu_alloc_mutex){+.+.}-{4:4}, at:
pcpu_alloc_noprof+0x284/0x16b0 mm/percpu.c:1782
other info that might help us debug this:
context-{5:5}
1 lock held by syz-executor234/5832:
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire
include/linux/rcupdate.h:331 [inline]
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock
include/linux/rcupdate.h:841 [inline]
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at:
ip6_route_add+0x4d/0x2f0 net/ipv6/route.c:3913
stack backtrace:
CPU: 0 UID: 0 PID: 5832 Comm: syz-executor234 Tainted: G W
6.15.0-rc4-syzkaller-00746-g836b313a14a3 #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 04/29/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4831 [inline]
check_wait_context kernel/locking/lockdep.c:4903 [inline]
__lock_acquire+0xbcf/0xd20 kernel/locking/lockdep.c:5185
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
pcpu_alloc_noprof+0x284/0x16b0 mm/percpu.c:1782
dst_cache_init+0x37/0xc0 net/core/dst_cache.c:145
ip_tun_build_state+0x193/0x6b0 net/ipv4/ip_tunnel_core.c:687
lwtunnel_build_state+0x381/0x4c0 net/core/lwtunnel.c:137
fib_nh_common_init+0x129/0x460 net/ipv4/fib_semantics.c:635
fib6_nh_init+0x15e4/0x2030 net/ipv6/route.c:3669
ip6_route_info_create_nh+0x139/0x870 net/ipv6/route.c:3866
ip6_route_add+0xf6/0x2f0 net/ipv6/route.c:3915
inet6_rtm_newroute+0x284/0x1c50 net/ipv6/route.c:5732
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
____sys_sendmsg+0x505/0x830 net/socket.c:2566
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
Fixes: 169fd62799 ("ipv6: Get rid of RTNL for SIOCADDRT and RTM_NEWROUTE.")
Reported-by: syzbot+bcc12d6799364500fbec@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bcc12d6799364500fbec
Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/netdev/CANn89i+r1cGacVC_6n3-A-WSkAa_Nr+pmxJ7Gt+oP-P9by2aGw@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit f130a0cc1b ("inet: fix lwtunnel_valid_encap_type() lock
imbalance") added the rtnl_is_held argument as a temporary fix while
I'm converting nexthop and IPv6 routing table to per-netns RTNL or RCU.
Now all callers of lwtunnel_valid_encap_type() do not hold RTNL.
Let's remove the argument.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
