linux-stable.git/net/ipv4/devinet.c, branch linux-5.4.y

ipv4: Fix NULL vs error pointer check in inet_blackhole_dev_init()

2025-09-09T16:43:58+00:00

[ Upstream commit a51160f8da850a65afbf165f5bbac7ffb388bf74 ]

The inetdev_init() function never returns NULL.  Check for error
pointers instead.

Fixes: 22600596b675 ("ipv4: give an IPv4 dev to blackhole_netdev")
Signed-off-by: Dan Carpenter 
Reviewed-by: Simon Horman 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/aLaQWL9NguWmeM1i@stanley.mountain
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv4: use RCU protection in inet_select_addr()

2025-03-13T11:43:17+00:00

[ Upstream commit 719817cd293e4fa389e1f69c396f3f816ed5aa41 ]

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 
Link: https://patch.msgid.link/20250205155120.1676781-7-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv4: give an IPv4 dev to blackhole_netdev

2024-11-08T15:20:49+00:00

[ Upstream commit 22600596b6756b166fd052d5facb66287e6f0bad ]

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 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/3000792d45ca44e16c785ebe2b092e610e5b3df1.1728499633.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv4: Check !in_dev earlier for ioctl(SIOCSIFADDR).

2024-11-08T15:20:37+00:00

[ Upstream commit e3af3d3c5b26c33a7950e34e137584f6056c4319 ]

dev->ip_ptr could be NULL if we set an invalid MTU.

Even then, if we issue ioctl(SIOCSIFADDR) for a new IPv4 address,
devinet_ioctl() allocates struct in_ifaddr and fails later in
inet_set_ifa() because in_dev is NULL.

Let's move the check earlier.

Signed-off-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20240809235406.50187-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid

2024-03-01T12:13:37+00:00

[ Upstream commit 081a0e3b0d4c061419d3f4679dec9f68725b17e4 ]

net->dev_base_seq and ipv4.dev_addr_genid are monotonically increasing.

If we XOR their values, we could miss to detect if both values
were changed with the same amount.

Fixes: 0465277f6b3f ("ipv4: provide addr and netconf dump consistency info")
Signed-off-by: Eric Dumazet 
Cc: Nicolas Dichtel 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipv4: fix one memleak in __inet_del_ifa()

2023-09-23T09:00:01+00:00

[ Upstream commit ac28b1ec6135649b5d78b028e47264cb3ebca5ea ]

I got the below warning when do fuzzing test:
unregister_netdevice: waiting for bond0 to become free. Usage count = 2

It can be repoduced via:

ip link add bond0 type bond
sysctl -w net.ipv4.conf.bond0.promote_secondaries=1
ip addr add 4.117.174.103/0 scope 0x40 dev bond0
ip addr add 192.168.100.111/255.255.255.254 scope 0 dev bond0
ip addr add 0.0.0.4/0 scope 0x40 secondary dev bond0
ip addr del 4.117.174.103/0 scope 0x40 dev bond0
ip link delete bond0 type bond

In this reproduction test case, an incorrect 'last_prim' is found in
__inet_del_ifa(), as a result, the secondary address(0.0.0.4/0 scope 0x40)
is lost. The memory of the secondary address is leaked and the reference of
in_device and net_device is leaked.

Fix this problem:
Look for 'last_prim' starting at location of the deleted IP and inserting
the promoted IP into the location of 'last_prim'.

Fixes: 0ff60a45678e ("[IPV4]: Fix secondary IP addresses after promotion")
Signed-off-by: Liu Jian 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: return correct error code

2021-12-08T08:01:09+00:00

[ Upstream commit 6def480181f15f6d9ec812bca8cbc62451ba314c ]

When kmemdup called failed and register_net_sysctl return NULL, should
return ENOMEM instead of ENOBUFS

Signed-off-by: liuguoqiang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: ipv4: Remove unneed BUG() function

2021-06-30T12:47:46+00:00

[ Upstream commit 5ac6b198d7e312bd10ebe7d58c64690dc59cc49a ]

When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.

Signed-off-by: Zheng Yongjun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

devinet: fix memleak in inetdev_init()

2020-06-10T18:24:54+00:00

[ Upstream commit 1b49cd71b52403822731dc9f283185d1da355f97 ]

When devinet_sysctl_register() failed, the memory allocated
in neigh_parms_alloc() should be freed.

Fixes: 20e61da7ffcf ("ipv4: fail early when creating netdev named all or default")
Signed-off-by: Yang Yingliang 
Acked-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv4: devinet: Fix crash when add/del multicast IP with autojoin

2020-04-21T07:04:45+00:00

[ Upstream commit 690cc86321eb9bcee371710252742fb16fe96824 ]

When CONFIG_IP_MULTICAST is not set and multicast ip is added to the device
with autojoin flag or when multicast ip is deleted kernel will crash.

steps to reproduce:

ip addr add 224.0.0.0/32 dev eth0
ip addr del 224.0.0.0/32 dev eth0

or

ip addr add 224.0.0.0/32 dev eth0 autojoin

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088
 pc : _raw_write_lock_irqsave+0x1e0/0x2ac
 lr : lock_sock_nested+0x1c/0x60
 Call trace:
  _raw_write_lock_irqsave+0x1e0/0x2ac
  lock_sock_nested+0x1c/0x60
  ip_mc_config.isra.28+0x50/0xe0
  inet_rtm_deladdr+0x1a8/0x1f0
  rtnetlink_rcv_msg+0x120/0x350
  netlink_rcv_skb+0x58/0x120
  rtnetlink_rcv+0x14/0x20
  netlink_unicast+0x1b8/0x270
  netlink_sendmsg+0x1a0/0x3b0
  ____sys_sendmsg+0x248/0x290
  ___sys_sendmsg+0x80/0xc0
  __sys_sendmsg+0x68/0xc0
  __arm64_sys_sendmsg+0x20/0x30
  el0_svc_common.constprop.2+0x88/0x150
  do_el0_svc+0x20/0x80
 el0_sync_handler+0x118/0x190
  el0_sync+0x140/0x180

Fixes: 93a714d6b53d ("multicast: Extend ip address command to enable multicast group join/leave on")
Signed-off-by: Taras Chornyi 
Signed-off-by: Vadym Kochan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman