linux-stable.git/net/core/net-sysfs.c, branch linux-5.8.y Linux kernel stable tree net-sysfs: add a newline when printing 'tx_timeout' by sysfs 2020-07-21T22:35:58+00:00 Xiongfeng Wang wangxiongfeng2@huawei.com 2020-07-21T07:02:57+00:00 9bb5fbea59f36a589ef886292549ca4052fe676c When I cat 'tx_timeout' by sysfs, it displays as follows. It's better to add a newline for easy reading. root@syzkaller:~# cat /sys/devices/virtual/net/lo/queues/tx-0/tx_timeout 0root@syzkaller:~# Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When I cat 'tx_timeout' by sysfs, it displays as follows. It's better to
add a newline for easy reading.

root@syzkaller:~# cat /sys/devices/virtual/net/lo/queues/tx-0/tx_timeout
0root@syzkaller:~#

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: core: recursively find netdev by device node 2020-05-15T17:18:49+00:00 Tobias Waldekranz tobias@waldekranz.com 2020-05-15T09:52:52+00:00 2e186a2cf8c785f38ef3237e83f8921f82f6e2b7 The assumption that a device node is associated either with the netdev's device, or the parent of that device, does not hold for all drivers. E.g. Freescale's DPAA has two layers of platform devices above the netdev. Instead, recursively walk up the tree from the netdev, allowing any parent to match against the sought after node. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The assumption that a device node is associated either with the
netdev's device, or the parent of that device, does not hold for all
drivers. E.g. Freescale's DPAA has two layers of platform devices
above the netdev. Instead, recursively walk up the tree from the
netdev, allowing any parent to match against the sought after node.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: napi: use READ_ONCE()/WRITE_ONCE() 2020-04-23T19:43:20+00:00 Eric Dumazet edumazet@google.com 2020-04-22T16:13:28+00:00 7e417a66b86c110f4b282945dac82e21e0b08328 gro_flush_timeout and napi_defer_hard_irqs can be read from napi_complete_done() while other cpus write the value, whithout explicit synchronization. Use READ_ONCE()/WRITE_ONCE() to annotate the races. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
gro_flush_timeout and napi_defer_hard_irqs can be read
from napi_complete_done() while other cpus write the value,
whithout explicit synchronization.

Use READ_ONCE()/WRITE_ONCE() to annotate the races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: napi: add hard irqs deferral feature 2020-04-23T19:43:20+00:00 Eric Dumazet edumazet@google.com 2020-04-22T16:13:27+00:00 6f8b12d661d09b488b9ac879b8eafbd2cc4a1450 Back in commit 3b47d30396ba ("net: gro: add a per device gro flush timer") we added the ability to arm one high resolution timer, that we used to keep not-complete packets in GRO engine a bit longer, hoping that further frames might be added to them. Since then, we added the napi_complete_done() interface, and commit 364b6055738b ("net: busy-poll: return busypolling status to drivers") allowed drivers to avoid re-arming NIC interrupts if we made a promise that their NAPI poll() handler would be called in the near future. This infrastructure can be leveraged, thanks to a new device parameter, which allows to arm the napi hrtimer, instead of re-arming the device hard IRQ. We have noticed that on some servers with 32 RX queues or more, the chit-chat between the NIC and the host caused by IRQ delivery and re-arming could hurt throughput by ~20% on 100Gbit NIC. In contrast, hrtimers are using local (percpu) resources and might have lower cost. The new tunable, named napi_defer_hard_irqs, is placed in the same hierarchy than gro_flush_timeout (/sys/class/net/ethX/) By default, both gro_flush_timeout and napi_defer_hard_irqs are zero. This patch does not change the prior behavior of gro_flush_timeout if used alone : NIC hard irqs should be rearmed as before. One concrete usage can be : echo 20000 >/sys/class/net/eth1/gro_flush_timeout echo 10 >/sys/class/net/eth1/napi_defer_hard_irqs If at least one packet is retired, then we will reset napi counter to 10 (napi_defer_hard_irqs), ensuring at least 10 periodic scans of the queue. On busy queues, this should avoid NIC hard IRQ, while before this patch IRQ avoidance was only possible if napi->poll() was exhausting its budget and not call napi_complete_done(). This feature also can be used to work around some non-optimal NIC irq coalescing strategies. Having the ability to insert XX usec delays between each napi->poll() can increase cache efficiency, since we increase batch sizes. It also keeps serving cpus not idle too long, reducing tail latencies. Co-developed-by: Luigi Rizzo <lrizzo@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Back in commit 3b47d30396ba ("net: gro: add a per device gro flush timer")
we added the ability to arm one high resolution timer, that we used
to keep not-complete packets in GRO engine a bit longer, hoping that further
frames might be added to them.

Since then, we added the napi_complete_done() interface, and commit
364b6055738b ("net: busy-poll: return busypolling status to drivers")
allowed drivers to avoid re-arming NIC interrupts if we made a promise
that their NAPI poll() handler would be called in the near future.

This infrastructure can be leveraged, thanks to a new device parameter,
which allows to arm the napi hrtimer, instead of re-arming the device
hard IRQ.

We have noticed that on some servers with 32 RX queues or more, the chit-chat
between the NIC and the host caused by IRQ delivery and re-arming could hurt
throughput by ~20% on 100Gbit NIC.

In contrast, hrtimers are using local (percpu) resources and might have lower
cost.

The new tunable, named napi_defer_hard_irqs, is placed in the same hierarchy
than gro_flush_timeout (/sys/class/net/ethX/)

By default, both gro_flush_timeout and napi_defer_hard_irqs are zero.

This patch does not change the prior behavior of gro_flush_timeout
if used alone : NIC hard irqs should be rearmed as before.

One concrete usage can be :

echo 20000 >/sys/class/net/eth1/gro_flush_timeout
echo 10 >/sys/class/net/eth1/napi_defer_hard_irqs

If at least one packet is retired, then we will reset napi counter
to 10 (napi_defer_hard_irqs), ensuring at least 10 periodic scans
of the queue.

On busy queues, this should avoid NIC hard IRQ, while before this patch IRQ
avoidance was only possible if napi->poll() was exhausting its budget
and not call napi_complete_done().

This feature also can be used to work around some non-optimal NIC irq
coalescing strategies.

Having the ability to insert XX usec delays between each napi->poll()
can increase cache efficiency, since we increase batch sizes.

It also keeps serving cpus not idle too long, reducing tail latencies.

Co-developed-by: Luigi Rizzo <lrizzo@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Add testing sysfs attribute 2020-04-20T19:43:24+00:00 Andrew Lunn andrew@lunn.ch 2020-04-19T22:11:51+00:00 db30a57779b18b7cef092c21887ed2d23ad2bd35 Similar to speed, duplex and dorment, report the testing status in sysfs. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Similar to speed, duplex and dorment, report the testing status
in sysfs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-sysfs: remove redundant assignment to variable ret 2020-04-09T17:14:53+00:00 Colin Ian King colin.king@canonical.com 2020-04-09T13:41:26+00:00 5f0224a6ddc3101ab9664a5f7a6287047934a079 The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The variable ret is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-sysfs: add queue_change_owner() 2020-02-27T04:07:26+00:00 Christian Brauner christian.brauner@ubuntu.com 2020-02-27T03:37:18+00:00 d755407d4444c3e0fbd7d7c3aa666d595e9ab217 Add a function to change the owner of the queue entries for a network device when it is moved between network namespaces. Currently, when moving network devices between network namespaces the ownership of the corresponding queue sysfs entries are not changed. This leads to problems when tools try to operate on the corresponding sysfs files. Fix this. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add a function to change the owner of the queue entries for a network device
when it is moved between network namespaces.

Currently, when moving network devices between network namespaces the
ownership of the corresponding queue sysfs entries are not changed. This leads
to problems when tools try to operate on the corresponding sysfs files. Fix
this.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-sysfs: add netdev_change_owner() 2020-02-27T04:07:25+00:00 Christian Brauner christian.brauner@ubuntu.com 2020-02-27T03:37:17+00:00 e6dee9f3893c823dff9c7f33fe0a598ee25c78f7 Add a function to change the owner of a network device when it is moved between network namespaces. Currently, when moving network devices between network namespaces the ownership of the corresponding sysfs entries is not changed. This leads to problems when tools try to operate on the corresponding sysfs files. This leads to a bug whereby a network device that is created in a network namespaces owned by a user namespace will have its corresponding sysfs entry owned by the root user of the corresponding user namespace. If such a network device has to be moved back to the host network namespace the permissions will still be set to the user namespaces. This means unprivileged users can e.g. trigger uevents for such incorrectly owned devices. They can also modify the settings of the device itself. Both of these things are unwanted. For example, workloads will create network devices in the host network namespace. Other tools will then proceed to move such devices between network namespaces owner by other user namespaces. While the ownership of the device itself is updated in net/core/net-sysfs.c:dev_change_net_namespace() the corresponding sysfs entry for the device is not: drwxr-xr-x 5 nobody nobody 0 Jan 25 18:08 . drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 .. -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_assign_type -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_len -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 address -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 broadcast -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_changes -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_down_count -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_up_count -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_id -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_port -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dormant -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 duplex -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 flags -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 gro_flush_timeout -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifalias -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifindex -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 iflink -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 link_mode -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 mtu -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 name_assign_type -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 netdev_group -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 operstate -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_id -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_name -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_switch_id drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 power -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 proto_down drwxr-xr-x 4 nobody nobody 0 Jan 25 18:09 queues -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 speed drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 statistics lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:08 subsystem -> ../../../../class/net -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 tx_queue_len -r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 type -rw-r--r-- 1 nobody nobody 4096 Jan 25 18:08 uevent However, if a device is created directly in the network namespace then the device's sysfs permissions will be correctly updated: drwxr-xr-x 5 root root 0 Jan 25 18:12 . drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 .. -r--r--r-- 1 root root 4096 Jan 25 18:12 addr_assign_type -r--r--r-- 1 root root 4096 Jan 25 18:12 addr_len -r--r--r-- 1 root root 4096 Jan 25 18:12 address -r--r--r-- 1 root root 4096 Jan 25 18:12 broadcast -rw-r--r-- 1 root root 4096 Jan 25 18:12 carrier -r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_changes -r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_down_count -r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_up_count -r--r--r-- 1 root root 4096 Jan 25 18:12 dev_id -r--r--r-- 1 root root 4096 Jan 25 18:12 dev_port -r--r--r-- 1 root root 4096 Jan 25 18:12 dormant -r--r--r-- 1 root root 4096 Jan 25 18:12 duplex -rw-r--r-- 1 root root 4096 Jan 25 18:12 flags -rw-r--r-- 1 root root 4096 Jan 25 18:12 gro_flush_timeout -rw-r--r-- 1 root root 4096 Jan 25 18:12 ifalias -r--r--r-- 1 root root 4096 Jan 25 18:12 ifindex -r--r--r-- 1 root root 4096 Jan 25 18:12 iflink -r--r--r-- 1 root root 4096 Jan 25 18:12 link_mode -rw-r--r-- 1 root root 4096 Jan 25 18:12 mtu -r--r--r-- 1 root root 4096 Jan 25 18:12 name_assign_type -rw-r--r-- 1 root root 4096 Jan 25 18:12 netdev_group -r--r--r-- 1 root root 4096 Jan 25 18:12 operstate -r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_id -r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_name -r--r--r-- 1 root root 4096 Jan 25 18:12 phys_switch_id drwxr-xr-x 2 root root 0 Jan 25 18:12 power -rw-r--r-- 1 root root 4096 Jan 25 18:12 proto_down drwxr-xr-x 4 root root 0 Jan 25 18:12 queues -r--r--r-- 1 root root 4096 Jan 25 18:12 speed drwxr-xr-x 2 root root 0 Jan 25 18:12 statistics lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:12 subsystem -> ../../../../class/net -rw-r--r-- 1 root root 4096 Jan 25 18:12 tx_queue_len -r--r--r-- 1 root root 4096 Jan 25 18:12 type -rw-r--r-- 1 root root 4096 Jan 25 18:12 uevent Now, when creating a network device in a network namespace owned by a user namespace and moving it to the host the permissions will be set to the id that the user namespace root user has been mapped to on the host leading to all sorts of permission issues: 458752 drwxr-xr-x 5 458752 458752 0 Jan 25 18:12 . drwxr-xr-x 9 root root 0 Jan 25 18:08 .. -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_assign_type -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_len -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 address -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 broadcast -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_changes -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_down_count -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_up_count -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_id -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_port -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dormant -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 duplex -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 flags -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 gro_flush_timeout -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 ifalias -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 ifindex -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 iflink -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 link_mode -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 mtu -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 name_assign_type -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 netdev_group -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 operstate -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_id -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_name -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_switch_id drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 power -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 proto_down drwxr-xr-x 4 458752 458752 0 Jan 25 18:12 queues -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 speed drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 statistics lrwxrwxrwx 1 root root 0 Jan 25 18:12 subsystem -> ../../../../class/net -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 tx_queue_len -r--r--r-- 1 458752 458752 4096 Jan 25 18:12 type -rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 uevent Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add a function to change the owner of a network device when it is moved
between network namespaces.

Currently, when moving network devices between network namespaces the
ownership of the corresponding sysfs entries is not changed. This leads
to problems when tools try to operate on the corresponding sysfs files.
This leads to a bug whereby a network device that is created in a
network namespaces owned by a user namespace will have its corresponding
sysfs entry owned by the root user of the corresponding user namespace.
If such a network device has to be moved back to the host network
namespace the permissions will still be set to the user namespaces. This
means unprivileged users can e.g. trigger uevents for such incorrectly
owned devices. They can also modify the settings of the device itself.
Both of these things are unwanted.

For example, workloads will create network devices in the host network
namespace. Other tools will then proceed to move such devices between
network namespaces owner by other user namespaces. While the ownership
of the device itself is updated in
net/core/net-sysfs.c:dev_change_net_namespace() the corresponding sysfs
entry for the device is not:

drwxr-xr-x 5 nobody nobody    0 Jan 25 18:08 .
drwxr-xr-x 9 nobody nobody    0 Jan 25 18:08 ..
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_assign_type
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 address
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 broadcast
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_changes
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_down_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_up_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_port
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dormant
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 duplex
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 flags
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 gro_flush_timeout
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifalias
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifindex
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 iflink
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 link_mode
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 mtu
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 name_assign_type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 netdev_group
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 operstate
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_name
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_switch_id
drwxr-xr-x 2 nobody nobody    0 Jan 25 18:09 power
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 proto_down
drwxr-xr-x 4 nobody nobody    0 Jan 25 18:09 queues
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 speed
drwxr-xr-x 2 nobody nobody    0 Jan 25 18:09 statistics
lrwxrwxrwx 1 nobody nobody    0 Jan 25 18:08 subsystem -> ../../../../class/net
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 tx_queue_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:08 uevent

However, if a device is created directly in the network namespace then
the device's sysfs permissions will be correctly updated:

drwxr-xr-x 5 root   root      0 Jan 25 18:12 .
drwxr-xr-x 9 nobody nobody    0 Jan 25 18:08 ..
-r--r--r-- 1 root   root   4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 root   root   4096 Jan 25 18:12 addr_len
-r--r--r-- 1 root   root   4096 Jan 25 18:12 address
-r--r--r-- 1 root   root   4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 carrier
-r--r--r-- 1 root   root   4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 root   root   4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 root   root   4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 root   root   4096 Jan 25 18:12 dev_id
-r--r--r-- 1 root   root   4096 Jan 25 18:12 dev_port
-r--r--r-- 1 root   root   4096 Jan 25 18:12 dormant
-r--r--r-- 1 root   root   4096 Jan 25 18:12 duplex
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 flags
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 ifalias
-r--r--r-- 1 root   root   4096 Jan 25 18:12 ifindex
-r--r--r-- 1 root   root   4096 Jan 25 18:12 iflink
-r--r--r-- 1 root   root   4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 mtu
-r--r--r-- 1 root   root   4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 root   root   4096 Jan 25 18:12 operstate
-r--r--r-- 1 root   root   4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 root   root   4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 root   root   4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 root   root      0 Jan 25 18:12 power
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 root   root      0 Jan 25 18:12 queues
-r--r--r-- 1 root   root   4096 Jan 25 18:12 speed
drwxr-xr-x 2 root   root      0 Jan 25 18:12 statistics
lrwxrwxrwx 1 nobody nobody    0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 root   root   4096 Jan 25 18:12 type
-rw-r--r-- 1 root   root   4096 Jan 25 18:12 uevent

Now, when creating a network device in a network namespace owned by a
user namespace and moving it to the host the permissions will be set to
the id that the user namespace root user has been mapped to on the host
leading to all sorts of permission issues:

458752
drwxr-xr-x 5 458752 458752      0 Jan 25 18:12 .
drwxr-xr-x 9 root   root        0 Jan 25 18:08 ..
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 addr_len
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 address
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 carrier
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 dev_id
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 dev_port
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 dormant
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 duplex
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 flags
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 ifalias
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 ifindex
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 iflink
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 mtu
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 operstate
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 458752 458752      0 Jan 25 18:12 power
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 458752 458752      0 Jan 25 18:12 queues
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 speed
drwxr-xr-x 2 458752 458752      0 Jan 25 18:12 statistics
lrwxrwxrwx 1 root   root        0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 458752 458752   4096 Jan 25 18:12 type
-rw-r--r-- 1 458752 458752   4096 Jan 25 18:12 uevent

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-sysfs: Call dev_hold always in rx_queue_add_kobject 2019-12-18T06:57:11+00:00 Jouni Hogander jouni.hogander@unikie.com 2019-12-17T11:46:34+00:00 ddd9b5e3e765d8ed5a35786a6cb00111713fe161 Dev_hold has to be called always in rx_queue_add_kobject. Otherwise usage count drops below 0 in case of failure in kobject_init_and_add. Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject") Reported-by: syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Miller <davem@davemloft.net> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dev_hold has to be called always in rx_queue_add_kobject.
Otherwise usage count drops below 0 in case of failure in
kobject_init_and_add.

Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Reported-by: syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-sysfs: Call dev_hold always in netdev_queue_add_kobject 2019-12-07T04:37:28+00:00 Jouni Hogander jouni.hogander@unikie.com 2019-12-05T13:57:07+00:00 e0b60903b434a7ee21ba8d8659f207ed84101e89 Dev_hold has to be called always in netdev_queue_add_kobject. Otherwise usage count drops below 0 in case of failure in kobject_init_and_add. Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject") Reported-by: Hulk Robot <hulkci@huawei.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Miller <davem@davemloft.net> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dev_hold has to be called always in netdev_queue_add_kobject.
Otherwise usage count drops below 0 in case of failure in
kobject_init_and_add.

Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>