linux-stable.git/net, branch v6.9.4 Linux kernel stable tree ipv4: correctly iterate over the target netns in inet_dump_ifaddr() 2024-06-12T09:39:55+00:00 Alexander Mikhalitsyn aleksandr.mikhalitsyn@canonical.com 2024-05-28T20:30:30+00:00 c0b37b1cca2d62ea2d1398ba6943b229477cbe4e [ Upstream commit b8c8abefc07b47f0dc9342530b7618237df96724 ] A recent change to inet_dump_ifaddr had the function incorrectly iterate over net rather than tgt_net, resulting in the data coming for the incorrect network namespace. Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()") Reported-by: Stéphane Graber <stgraber@stgraber.org> Closes: https://github.com/lxc/incus/issues/892 Bisected-by: Stéphane Graber <stgraber@stgraber.org> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Tested-by: Stéphane Graber <stgraber@stgraber.org> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240528203030.10839-1-aleksandr.mikhalitsyn@canonical.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b8c8abefc07b47f0dc9342530b7618237df96724 ]

A recent change to inet_dump_ifaddr had the function incorrectly iterate
over net rather than tgt_net, resulting in the data coming for the
incorrect network namespace.

Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Stéphane Graber <stgraber@stgraber.org>
Closes: https://github.com/lxc/incus/issues/892
Bisected-by: Stéphane Graber <stgraber@stgraber.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Tested-by: Stéphane Graber <stgraber@stgraber.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240528203030.10839-1-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: fix __dst_negative_advice() race 2024-06-12T09:39:55+00:00 Eric Dumazet edumazet@google.com 2024-05-28T11:43:53+00:00 b8af8e6118a6605f0e495a58d591ca94a85a50fc [ Upstream commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e ] __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets. Fixes: a87cb3e48ee8 ("net: Facility to report route quality of connected sockets") Reported-by: Clement Lecigne <clecigne@google.com> Diagnosed-by: Clement Lecigne <clecigne@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <tom@herbertland.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e ]

__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.

RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).

Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.

Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.

Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.

Many thanks to Clement Lecigne for tracking this issue.

This old bug became visible after the blamed commit, using UDP sockets.

Fixes: a87cb3e48ee8 ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
inet: introduce dst_rtable() helper 2024-06-12T09:39:55+00:00 Eric Dumazet edumazet@google.com 2024-04-29T13:30:09+00:00 a97788b86d9d1531a0bee8b64b0c983889cbc899 [ Upstream commit 05d6d492097c55f2d153fc3fd33cbe78e1e28e0a ] I added dst_rt6_info() in commit e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper") This patch does a similar change for IPv4. Instead of (struct rtable *)dst casts, we can use : #define dst_rtable(_ptr) \ container_of_const(_ptr, struct rtable, dst) Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 92f1655aa2b2 ("net: fix __dst_negative_advice() race") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 05d6d492097c55f2d153fc3fd33cbe78e1e28e0a ]

I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")

This patch does a similar change for IPv4.

Instead of (struct rtable *)dst casts, we can use :

 #define dst_rtable(_ptr) \
             container_of_const(_ptr, struct rtable, dst)

Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 92f1655aa2b2 ("net: fix __dst_negative_advice() race")
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv6: introduce dst_rt6_info() helper 2024-06-12T09:39:54+00:00 Eric Dumazet edumazet@google.com 2024-04-26T15:19:52+00:00 30c83ed52fee13fd64bca8b08763fe98f3bea8a7 [ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ] Instead of (struct rt6_info *)dst casts, we can use : #define dst_rt6_info(_ptr) \ container_of_const(_ptr, struct rt6_info, dst) Some places needed missing const qualifiers : ip6_confirm_neigh(), ipv6_anycast_destination(), ipv6_unicast_destination(), has_gateway() v2: added missing parts (David Ahern) Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 92f1655aa2b2 ("net: fix __dst_negative_advice() race") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ]

Instead of (struct rt6_info *)dst casts, we can use :

 #define dst_rt6_info(_ptr) \
         container_of_const(_ptr, struct rt6_info, dst)

Some places needed missing const qualifiers :

ip6_confirm_neigh(), ipv6_anycast_destination(),
ipv6_unicast_destination(), has_gateway()

v2: added missing parts (David Ahern)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 92f1655aa2b2 ("net: fix __dst_negative_advice() race")
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/sched: taprio: extend minimum interval restriction to entire cycle too 2024-06-12T09:39:53+00:00 Vladimir Oltean vladimir.oltean@nxp.com 2024-05-27T15:39:55+00:00 91f249b01fe490fce11fbb4307952ca8cce78724 [ Upstream commit fb66df20a7201e60f2b13d7f95d031b31a8831d3 ] It is possible for syzbot to side-step the restriction imposed by the blamed commit in the Fixes: tag, because the taprio UAPI permits a cycle-time different from (and potentially shorter than) the sum of entry intervals. We need one more restriction, which is that the cycle time itself must be larger than N * ETH_ZLEN bit times, where N is the number of schedule entries. This restriction needs to apply regardless of whether the cycle time came from the user or was the implicit, auto-calculated value, so we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)" branch. This way covers both conditions and scenarios. Add a selftest which illustrates the issue triggered by syzbot. Fixes: b5b73b26b3ca ("taprio: Fix allowing too small intervals") Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/ Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fb66df20a7201e60f2b13d7f95d031b31a8831d3 ]

It is possible for syzbot to side-step the restriction imposed by the
blamed commit in the Fixes: tag, because the taprio UAPI permits a
cycle-time different from (and potentially shorter than) the sum of
entry intervals.

We need one more restriction, which is that the cycle time itself must
be larger than N * ETH_ZLEN bit times, where N is the number of schedule
entries. This restriction needs to apply regardless of whether the cycle
time came from the user or was the implicit, auto-calculated value, so
we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)"
branch. This way covers both conditions and scenarios.

Add a selftest which illustrates the issue triggered by syzbot.

Fixes: b5b73b26b3ca ("taprio: Fix allowing too small intervals")
Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/sched: taprio: make q->picos_per_byte available to fill_sched_entry() 2024-06-12T09:39:53+00:00 Vladimir Oltean vladimir.oltean@nxp.com 2024-05-27T15:39:54+00:00 6239e4cd1fde091d6f0502a4af3ba5153c8a1086 [ Upstream commit e634134180885574d1fe7aa162777ba41e7fcd5b ] In commit b5b73b26b3ca ("taprio: Fix allowing too small intervals"), a comparison of user input against length_to_duration(q, ETH_ZLEN) was introduced, to avoid RCU stalls due to frequent hrtimers. The implementation of length_to_duration() depends on q->picos_per_byte being set for the link speed. The blamed commit in the Fixes: tag has moved this too late, so the checks introduced above are ineffective. The q->picos_per_byte is zero at parse_taprio_schedule() -> parse_sched_list() -> parse_sched_entry() -> fill_sched_entry() time. Move the taprio_set_picos_per_byte() call as one of the first things in taprio_change(), before the bulk of the netlink attribute parsing is done. That's because it is needed there. Add a selftest to make sure the issue doesn't get reintroduced. Fixes: 09dbdf28f9f9 ("net/sched: taprio: fix calculation of maximum gate durations") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e634134180885574d1fe7aa162777ba41e7fcd5b ]

In commit b5b73b26b3ca ("taprio: Fix allowing too small intervals"), a
comparison of user input against length_to_duration(q, ETH_ZLEN) was
introduced, to avoid RCU stalls due to frequent hrtimers.

The implementation of length_to_duration() depends on q->picos_per_byte
being set for the link speed. The blamed commit in the Fixes: tag has
moved this too late, so the checks introduced above are ineffective.
The q->picos_per_byte is zero at parse_taprio_schedule() ->
parse_sched_list() -> parse_sched_entry() -> fill_sched_entry() time.

Move the taprio_set_picos_per_byte() call as one of the first things in
taprio_change(), before the bulk of the netlink attribute parsing is
done. That's because it is needed there.

Add a selftest to make sure the issue doesn't get reintroduced.

Fixes: 09dbdf28f9f9 ("net/sched: taprio: fix calculation of maximum gate durations")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: nft_fib: allow from forward/input without iif selector 2024-06-12T09:39:53+00:00 Eric Garver eric@garver.life 2024-05-21T14:25:05+00:00 c115b10e4f952f38b29d3c03d57354a7fbe9aa86 [ Upstream commit e8ded22ef0f4831279c363c264cd41cd9d59ca9e ] This removes the restriction of needing iif selector in the forward/input hooks for fib lookups when requested result is oif/oifname. Removing this restriction allows "loose" lookups from the forward hooks. Fixes: be8be04e5ddb ("netfilter: nft_fib: reverse path filter for policy-based routing on iif") Signed-off-by: Eric Garver <eric@garver.life> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e8ded22ef0f4831279c363c264cd41cd9d59ca9e ]

This removes the restriction of needing iif selector in the
forward/input hooks for fib lookups when requested result is
oif/oifname.

Removing this restriction allows "loose" lookups from the forward hooks.

Fixes: be8be04e5ddb ("netfilter: nft_fib: reverse path filter for policy-based routing on iif")
Signed-off-by: Eric Garver <eric@garver.life>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: tproxy: bail out if IP has been disabled on the device 2024-06-12T09:39:53+00:00 Florian Westphal fw@strlen.de 2024-05-13T10:27:15+00:00 819bfeca16eb9ad647ddcae25e7e12c30612147c [ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ] syzbot reports: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] [..] RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62 Call Trace: nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline] nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168 __in_dev_get_rcu() can return NULL, so check for this. Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ]

syzbot reports:
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
[..]
RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62
Call Trace:
 nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline]
 nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168

__in_dev_get_rcu() can return NULL, so check for this.

Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com
Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: nft_payload: skbuff vlan metadata mangle support 2024-06-12T09:39:53+00:00 Pablo Neira Ayuso pablo@netfilter.org 2024-05-08T20:50:34+00:00 06fa4c04e844e4d662c7d8a787b420b3da281d42 [ Upstream commit 33c563ebf8d3deed7d8addd20d77398ac737ef9a ] Userspace assumes vlan header is present at a given offset, but vlan offload allows to store this in metadata fields of the skbuff. Hence mangling vlan results in a garbled packet. Handle this transparently by adding a parser to the kernel. If vlan metadata is present and payload offset is over 12 bytes (source and destination mac address fields), then subtract vlan header present in vlan metadata, otherwise mangle vlan metadata based on offset and length, extracting data from the source register. This is similar to: 8cfd23e67401 ("netfilter: nft_payload: work around vlan header stripping") to deal with vlan payload mangling. Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 33c563ebf8d3deed7d8addd20d77398ac737ef9a ]

Userspace assumes vlan header is present at a given offset, but vlan
offload allows to store this in metadata fields of the skbuff. Hence
mangling vlan results in a garbled packet. Handle this transparently by
adding a parser to the kernel.

If vlan metadata is present and payload offset is over 12 bytes (source
and destination mac address fields), then subtract vlan header present
in vlan metadata, otherwise mangle vlan metadata based on offset and
length, extracting data from the source register.

This is similar to:

  8cfd23e67401 ("netfilter: nft_payload: work around vlan header stripping")

to deal with vlan payload mangling.

Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipv4: Fix address dump when IPv4 is disabled on an interface 2024-06-12T09:39:50+00:00 Ido Schimmel idosch@nvidia.com 2024-05-23T11:02:57+00:00 0e09218399e6ee371cfc55d545c93c620e27f8f9 [ Upstream commit 7b05ab85e28f615e70520d24c075249b4512044e ] Cited commit started returning an error when user space requests to dump the interface's IPv4 addresses and IPv4 is disabled on the interface. Restore the previous behavior and do not return an error. Before cited commit: # ip address show dev dummy1 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff inet6 fe80::e040:68ff:fe98:d018/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 67 # ip address show dev dummy1 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff After cited commit: # ip address show dev dummy1 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether 32:2d:69:f2:9c:99 brd ff:ff:ff:ff:ff:ff inet6 fe80::302d:69ff:fef2:9c99/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 67 # ip address show dev dummy1 RTNETLINK answers: No such device Dump terminated With this patch: # ip address show dev dummy1 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff inet6 fe80::dc17:56ff:febb:57c0/64 scope link proto kernel_ll valid_lft forever preferred_lft forever # ip link set dev dummy1 mtu 67 # ip address show dev dummy1 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff I fixed the exact same issue for IPv6 in commit c04f7dfe6ec2 ("ipv6: Fix address dump when IPv6 is disabled on an interface"), but noted [1] that I am not doing the change for IPv4 because I am not aware of a way to disable IPv4 on an interface other than unregistering it. I clearly missed the above case. [1] https://lore.kernel.org/netdev/20240321173042.2151756-1-idosch@nvidia.com/ Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()") Reported-by: Carolina Jubran <cjubran@nvidia.com> Reported-by: Yamen Safadi <ysafadi@nvidia.com> Tested-by: Carolina Jubran <cjubran@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240523110257.334315-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7b05ab85e28f615e70520d24c075249b4512044e ]

Cited commit started returning an error when user space requests to dump
the interface's IPv4 addresses and IPv4 is disabled on the interface.
Restore the previous behavior and do not return an error.

Before cited commit:

 # ip address show dev dummy1
 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::e040:68ff:fe98:d018/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff

After cited commit:

 # ip address show dev dummy1
 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether 32:2d:69:f2:9c:99 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::302d:69ff:fef2:9c99/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 RTNETLINK answers: No such device
 Dump terminated

With this patch:

 # ip address show dev dummy1
 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::dc17:56ff:febb:57c0/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 10: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff

I fixed the exact same issue for IPv6 in commit c04f7dfe6ec2 ("ipv6: Fix
address dump when IPv6 is disabled on an interface"), but noted [1] that
I am not doing the change for IPv4 because I am not aware of a way to
disable IPv4 on an interface other than unregistering it. I clearly
missed the above case.

[1] https://lore.kernel.org/netdev/20240321173042.2151756-1-idosch@nvidia.com/

Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Carolina Jubran <cjubran@nvidia.com>
Reported-by: Yamen Safadi <ysafadi@nvidia.com>
Tested-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240523110257.334315-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>