net: switch to netif_disable_lro in inetdev_init

Cosmin reports the following deadlock:
dump_stack_lvl+0x62/0x90
print_deadlock_bug+0x274/0x3b0
__lock_acquire+0x1229/0x2470
lock_acquire+0xb7/0x2b0
_

net: switch to netif_disable_lro in inetdev_init

Cosmin reports the following deadlock:
dump_stack_lvl+0x62/0x90
print_deadlock_bug+0x274/0x3b0
__lock_acquire+0x1229/0x2470
lock_acquire+0xb7/0x2b0
__mutex_lock+0xa6/0xd20
dev_disable_lro+0x20/0x80
inetdev_init+0x12f/0x1f0
inetdev_event+0x48b/0x870
notifier_call_chain+0x38/0xf0
netif_change_net_namespace+0x72e/0x9f0
do_setlink.isra.0+0xd5/0x1220
rtnl_newlink+0x7ea/0xb50
rtnetlink_rcv_msg+0x459/0x5e0
netlink_rcv_skb+0x54/0x100
netlink_unicast+0x193/0x270
netlink_sendmsg+0x204/0x450

Switch to netif_disable_lro which assumes the caller holds the instance
lock. inetdev_init is called for blackhole device (which sw device and
doesn't grab instance lock) and from REGISTER/UNREGISTER notifiers.
We already hold the instance lock for REGISTER notifier during
netns change and we'll soon hold the lock during other paths.

Reviewed-by: Jakub Kicinski <[email protected]>
Reported-by: Cosmin Ratiu <[email protected]>
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: support dumping IPv4 multicast addresses

Extended RTM_GETMULTICAST to support dumping joined IPv4 multicast
addresses, in addition to the existing IPv6 functionality. This allows
userspace

netlink: support dumping IPv4 multicast addresses

Extended RTM_GETMULTICAST to support dumping joined IPv4 multicast
addresses, in addition to the existing IPv6 functionality. This allows
userspace applications to retrieve both IPv4 and IPv6 multicast
addresses through similar netlink command and then monitor future
changes by registering to RTNLGRP_IPV4_MCADDR and RTNLGRP_IPV6_MCADDR.

Cc: Maciej Żenczykowski <[email protected]>
Cc: Lorenzo Colitti <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Yuyang Huang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: use RCU protection in inet_select_addr()

inet_select_addr() must use RCU protection to make
sure the net structure it reads does not disappear.

Fixes: c4544c724322 ("[NETNS]: Process inet_sel

ipv4: use RCU protection in inet_select_addr()

inet_select_addr() must use RCU protection to make
sure the net structure it reads does not disappear.

Fixes: c4544c724322 ("[NETNS]: Process inet_select_addr inside a namespace.")
Signed-off-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: convert to nla_get_*_default()

Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default va

net: convert to nla_get_*_default()

Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default values don't
fit into the type) or just looked strange.

@@
expression attr, def;
expression val;
identifier fn =~ "^nla_get_.*";
fresh identifier dfn = fn ## "_default";
@@
(
-if (attr)
- val = fn(attr);
-else
- val = def;
+val = dfn(attr, def);
|
-if (!attr)
- val = def;
-else
- val = fn(attr);
+val = dfn(attr, def);
|
-if (!attr)
- return def;
-return fn(attr);
+return dfn(attr, def);
|
-attr ? fn(attr) : def
+dfn(attr, def)
|
-!attr ? def : fn(attr)
+dfn(attr, def)
)

Signed-off-by: Johannes Berg <[email protected]>
Reviewed-by: Toke Høiland-Jørgensen <[email protected]>
Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Convert devinet_ioctl to per-netns RTNL.

ioctl(SIOCGIFCONF) calls dev_ifconf() that operates on the current netns.

Let's use per-netns RTNL helpers in dev_ifconf() and inet_gifconf().

Signed

ipv4: Convert devinet_ioctl to per-netns RTNL.

ioctl(SIOCGIFCONF) calls dev_ifconf() that operates on the current netns.

Let's use per-netns RTNL helpers in dev_ifconf() and inet_gifconf().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Convert devinet_ioctl() to per-netns RTNL except for SIOCSIFFLAGS.

Basically, devinet_ioctl() operates on a single netns.

However, ioctl(SIOCSIFFLAGS) will trigger the netdev notifier
that co

ipv4: Convert devinet_ioctl() to per-netns RTNL except for SIOCSIFFLAGS.

Basically, devinet_ioctl() operates on a single netns.

However, ioctl(SIOCSIFFLAGS) will trigger the netdev notifier
that could touch another netdev in different netns.

Let's use per-netns RTNL helper in devinet_ioctl() and place
ASSERT_RTNL() for SIOCSIFFLAGS.

We will remove ASSERT_RTNL() once RTM_SETLINK and RTM_DELLINK
are converted.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Convert devinet_sysctl_forward() to per-netns RTNL.

devinet_sysctl_forward() touches only a single netns.

Let's use rtnl_trylock() and __in_dev_get_rtnl_net().

Signed-off-by: Kuniyuki Iwashi

ipv4: Convert devinet_sysctl_forward() to per-netns RTNL.

devinet_sysctl_forward() touches only a single netns.

Let's use rtnl_trylock() and __in_dev_get_rtnl_net().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Convert check_lifetime() to per-netns RTNL.

Since commit 1675f385213e ("ipv4: Namespacify IPv4 address GC."),
check_lifetime() works on a per-netns basis.

Let's use rtnl_net_lock() and rtnl_n

ipv4: Convert check_lifetime() to per-netns RTNL.

Since commit 1675f385213e ("ipv4: Namespacify IPv4 address GC."),
check_lifetime() works on a per-netns basis.

Let's use rtnl_net_lock() and rtnl_net_dereference().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Convert RTM_DELADDR to per-netns RTNL.

Let's push down RTNL into inet_rtm_deladdr() as rtnl_net_lock().

Now, ip_mc_autojoin_config() is always called under per-netns RTNL,
so ASSERT_RTNL() ca

ipv4: Convert RTM_DELADDR to per-netns RTNL.

Let's push down RTNL into inet_rtm_deladdr() as rtnl_net_lock().

Now, ip_mc_autojoin_config() is always called under per-netns RTNL,
so ASSERT_RTNL() can be replaced with ASSERT_RTNL_NET().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Use per-netns RTNL helpers in inet_rtm_newaddr().

inet_rtm_to_ifa() and find_matching_ifa() are called
under rtnl_net_lock().

__in_dev_get_rtnl() and in_dev_for_each_ifa_rtnl() there
can use

ipv4: Use per-netns RTNL helpers in inet_rtm_newaddr().

inet_rtm_to_ifa() and find_matching_ifa() are called
under rtnl_net_lock().

__in_dev_get_rtnl() and in_dev_for_each_ifa_rtnl() there
can use per-netns RTNL helpers.

Let's define and use __in_dev_get_rtnl_net() and
in_dev_for_each_ifa_rtnl_net().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Convert RTM_NEWADDR to per-netns RTNL.

The address hash table and GC are already namespacified.

Let's push down RTNL into inet_rtm_newaddr() as rtnl_net_lock().

Signed-off-by: Kuniyuki Iwash

ipv4: Convert RTM_NEWADDR to per-netns RTNL.

The address hash table and GC are already namespacified.

Let's push down RTNL into inet_rtm_newaddr() as rtnl_net_lock().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Don't allocate ifa for 0.0.0.0 in inet_rtm_newaddr().

When we pass 0.0.0.0 to __inet_insert_ifa(), it frees ifa and returns 0.

We can do this check much earlier for RTM_NEWADDR even before al

ipv4: Don't allocate ifa for 0.0.0.0 in inet_rtm_newaddr().

When we pass 0.0.0.0 to __inet_insert_ifa(), it frees ifa and returns 0.

We can do this check much earlier for RTM_NEWADDR even before allocating
struct in_ifaddr.

Let's move the validation to

1. inet_insert_ifa() for ioctl()
2. inet_rtm_newaddr() for RTM_NEWADDR

Now, we can remove the same check in find_matching_ifa().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Factorise RTM_NEWADDR validation to inet_validate_rtm().

rtm_to_ifaddr() validates some attributes, looks up a netdev,
allocates struct in_ifaddr, and validates IFA_CACHEINFO.

There is no rea

ipv4: Factorise RTM_NEWADDR validation to inet_validate_rtm().

rtm_to_ifaddr() validates some attributes, looks up a netdev,
allocates struct in_ifaddr, and validates IFA_CACHEINFO.

There is no reason to delay IFA_CACHEINFO validation.

We will push RTNL down to inet_rtm_newaddr(), and then we want
to complete rtnetlink validation before rtnl_net_lock().

Let's factorise the validation parts.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Switch inet_addr_hash() to less predictable hash.

Recently, commit 4a0ec2aa0704 ("ipv6: switch inet6_addr_hash()
to less predictable hash") and commit 4daf4dc275f1 ("ipv6: switch
inet6_acaddr_

ipv4: Switch inet_addr_hash() to less predictable hash.

Recently, commit 4a0ec2aa0704 ("ipv6: switch inet6_addr_hash()
to less predictable hash") and commit 4daf4dc275f1 ("ipv6: switch
inet6_acaddr_hash() to less predictable hash") hardened IPv6
address hash functions.

inet_addr_hash() is also highly predictable, and a malicious use
could abuse a specific bucket.

Let's follow the change on IPv4 by using jhash_1word().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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rtnetlink: Return int from rtnl_af_register().

The next patch will add init_srcu_struct() in rtnl_af_register(),
then we need to handle its error.

Let's add the error handling in advance to make th

rtnetlink: Return int from rtnl_af_register().

The next patch will add init_srcu_struct() in rtnl_af_register(),
then we need to handle its error.

Let's add the error handling in advance to make the following
patch cleaner.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Matt Johnston <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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ipv4: Use rtnl_register_many().

We will remove rtnl_register() in favour of rtnl_register_many().

When it succeeds, rtnl_register_many() guarantees all rtnetlink types
in the passed array are suppo

ipv4: Use rtnl_register_many().

We will remove rtnl_register() in favour of rtnl_register_many().

When it succeeds, rtnl_register_many() guarantees all rtnetlink types
in the passed array are supported, and there is no chance that a part
of message types is not supported.

Let's use rtnl_register_many() instead.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: give an IPv4 dev to blackhole_netdev

After commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to
invalidate dst entries"), blackhole_netdev was introduced to invalidate
dst cache ent

ipv4: give an IPv4 dev to blackhole_netdev

After commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to
invalidate dst entries"), blackhole_netdev was introduced to invalidate
dst cache entries on the TX path whenever the cache times out or is
flushed.

When two UDP sockets (sk1 and sk2) send messages to the same destination
simultaneously, they are using the same dst cache. If the dst cache is
invalidated on one path (sk2) while the other (sk1) is still transmitting,
sk1 may try to use the invalid dst entry.

CPU1 CPU2

udp_sendmsg(sk1) udp_sendmsg(sk2)
udp_send_skb()
ip_output()
<--- dst timeout or flushed
dst_dev_put()
ip_finish_output2()
ip_neigh_for_gw()

This results in a scenario where ip_neigh_for_gw() returns -EINVAL because
blackhole_dev lacks an in_dev, which is needed to initialize the neigh in
arp_constructor(). This error is then propagated back to userspace,
breaking the UDP application.

The patch fixes this issue by assigning an in_dev to blackhole_dev for
IPv4, similar to what was done for IPv6 in commit e5f80fcf869a ("ipv6:
give an IPv6 dev to blackhole_netdev"). This ensures that even when the
dst entry is invalidated with blackhole_dev, it will not fail to create
the neigh entry.

As devinet_init() is called ealier than blackhole_netdev_init() in system
booting, it can not assign the in_dev to blackhole_dev in devinet_init().
As Paolo suggested, add a separate late_initcall() in devinet.c to ensure
inet_blackhole_dev_init() is called after blackhole_netdev_init().

Fixes: 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to invalidate dst entries")
Signed-off-by: Xin Long <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/3000792d45ca44e16c785ebe2b092e610e5b3df1.1728499633.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Retire global IPv4 hash table inet_addr_lst.

No one uses inet_addr_lst anymore, so let's remove it.

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Kuniyuki Iwashima <kuniyu@am

ipv4: Retire global IPv4 hash table inet_addr_lst.

No one uses inet_addr_lst anymore, so let's remove it.

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Namespacify IPv4 address GC.

Each IPv4 address could have a lifetime, which is useful for DHCP,
and GC is periodically executed as check_lifetime_work.

check_lifetime() does the actual GC und

ipv4: Namespacify IPv4 address GC.

Each IPv4 address could have a lifetime, which is useful for DHCP,
and GC is periodically executed as check_lifetime_work.

check_lifetime() does the actual GC under RTNL.

1. Acquire RTNL
2. Iterate inet_addr_lst
3. Remove IPv4 address if expired
4. Release RTNL

Namespacifying the GC is required for per-netns RTNL, but using the
per-netns hash table will shorten the time on the hash bucket iteration
under RTNL.

Let's add per-netns GC work and use the per-netns hash table.

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Use per-netns hash table in inet_lookup_ifaddr_rcu().

Now, all IPv4 addresses are put in the per-netns hash table.

Let's use it in inet_lookup_ifaddr_rcu().

Reviewed-by: Eric Dumazet <edumaz

ipv4: Use per-netns hash table in inet_lookup_ifaddr_rcu().

Now, all IPv4 addresses are put in the per-netns hash table.

Let's use it in inet_lookup_ifaddr_rcu().

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Link IPv4 address to per-netns hash table.

As a prep for per-netns RTNL conversion, we want to namespacify
the IPv4 address hash table and the GC work.

Let's allocate the per-netns IPv4 addre

ipv4: Link IPv4 address to per-netns hash table.

As a prep for per-netns RTNL conversion, we want to namespacify
the IPv4 address hash table and the GC work.

Let's allocate the per-netns IPv4 address hash table to
net->ipv4.inet_addr_lst and link IPv4 addresses into it.

The actual users will be converted later.

Note that the IPv6 address hash table is already namespacified.

Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: delete redundant judgment statements

The initial value of err is -ENOBUFS, and err is guaranteed to be
less than 0 before all goto errout. Therefore, on the error path
of errout, there is no n

ipv4: delete redundant judgment statements

The initial value of err is -ENOBUFS, and err is guaranteed to be
less than 0 before all goto errout. Therefore, on the error path
of errout, there is no need to repeatedly judge that err is less than 0,
and delete redundant judgments to make the code more concise.

Signed-off-by: Li Zetao <[email protected]>
Reviewed-by: Petr Machata <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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ip: Move INFINITY_LIFE_TIME to addrconf.h.

INFINITY_LIFE_TIME is the common value used in IPv4 and IPv6 but defined
in both .c files.

Also, 0xffffffff used in addrconf_timeout_fixup() is INFINITY_L

ip: Move INFINITY_LIFE_TIME to addrconf.h.

INFINITY_LIFE_TIME is the common value used in IPv4 and IPv6 but defined
in both .c files.

Also, 0xffffffff used in addrconf_timeout_fixup() is INFINITY_LIFE_TIME.

Let's move INFINITY_LIFE_TIME's definition to addrconf.h

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Initialise ifa->hash in inet_alloc_ifa().

Whenever ifa is allocated, we call INIT_HLIST_NODE(&ifa->hash).

Let's move it to inet_alloc_ifa().

Signed-off-by: Kuniyuki Iwashima <[email protected]

ipv4: Initialise ifa->hash in inet_alloc_ifa().

Whenever ifa is allocated, we call INIT_HLIST_NODE(&ifa->hash).

Let's move it to inet_alloc_ifa().

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv4: Remove redundant !ifa->ifa_dev check.

Now, ifa_dev is only set in inet_alloc_ifa() and never
NULL after ifa gets visible.

Let's remove the unneeded NULL check for ifa->ifa_dev.

Signed-off-by

ipv4: Remove redundant !ifa->ifa_dev check.

Now, ifa_dev is only set in inet_alloc_ifa() and never
NULL after ifa gets visible.

Let's remove the unneeded NULL check for ifa->ifa_dev.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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