linux-stable.git/net/core/rtnetlink.c, branch v5.13.2 Linux kernel stable tree rtnetlink: avoid RCU read lock when holding RTNL 2021-07-14T15:06:56+00:00 Cong Wang cong.wang@bytedance.com 2021-05-08T18:00:33+00:00 4e953e501b9f0ce93480badfd96e01d1b288952a [ Upstream commit a100243d95a60d74ae9bb9df1f5f2192e9aed6a7 ] When we call af_ops->set_link_af() we hold a RCU read lock as we retrieve af_ops from the RCU protected list, but this is unnecessary because we already hold RTNL lock, which is the writer lock for protecting rtnl_af_ops, so it is safer than RCU read lock. Similar for af_ops->validate_link_af(). This was not a problem until we begin to take mutex lock down the path of ->set_link_af() in __ipv6_dev_mc_dec() recently. We can just drop the RCU read lock there and assert RTNL lock. Reported-and-tested-by: syzbot+7d941e89dd48bcf42573@syzkaller.appspotmail.com Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data") Tested-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a100243d95a60d74ae9bb9df1f5f2192e9aed6a7 ]

When we call af_ops->set_link_af() we hold a RCU read lock
as we retrieve af_ops from the RCU protected list, but this
is unnecessary because we already hold RTNL lock, which is
the writer lock for protecting rtnl_af_ops, so it is safer
than RCU read lock. Similar for af_ops->validate_link_af().

This was not a problem until we begin to take mutex lock
down the path of ->set_link_af() in __ipv6_dev_mc_dec()
recently. We can just drop the RCU read lock there and
assert RTNL lock.

Reported-and-tested-by: syzbot+7d941e89dd48bcf42573@syzkaller.appspotmail.com
Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data")
Tested-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rtnetlink: Fix regression in bridge VLAN configuration 2021-06-09T21:58:26+00:00 Ido Schimmel idosch@nvidia.com 2021-06-09T11:17:53+00:00 d2e381c4963663bca6f30c3b996fa4dbafe8fcb5 Cited commit started returning errors when notification info is not filled by the bridge driver, resulting in the following regression: # ip link add name br1 type bridge vlan_filtering 1 # bridge vlan add dev br1 vid 555 self pvid untagged RTNETLINK answers: Invalid argument As long as the bridge driver does not fill notification info for the bridge device itself, an empty notification should not be considered as an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send notification when skb->len == 0 in rtnl_bridge_notify"). Fix by removing the error and add a comment to avoid future bugs. Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Cited commit started returning errors when notification info is not
filled by the bridge driver, resulting in the following regression:

 # ip link add name br1 type bridge vlan_filtering 1
 # bridge vlan add dev br1 vid 555 self pvid untagged
 RTNETLINK answers: Invalid argument

As long as the bridge driver does not fill notification info for the
bridge device itself, an empty notification should not be considered as
an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send
notification when skb->len == 0 in rtnl_bridge_notify").

Fix by removing the error and add a comment to avoid future bugs.

Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rtnetlink: Fix missing error code in rtnl_bridge_notify() 2021-06-03T20:56:27+00:00 Jiapeng Chong jiapeng.chong@linux.alibaba.com 2021-06-02T10:15:04+00:00 a8db57c1d285c758adc7fb43d6e2bad2554106e1 The error code is missing in this code scenario, add the error code '-EINVAL' to the return value 'err'. Eliminate the follow smatch warning: net/core/rtnetlink.c:4834 rtnl_bridge_notify() warn: missing error code 'err'. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'err'.

Eliminate the follow smatch warning:

net/core/rtnetlink.c:4834 rtnl_bridge_notify() warn: missing error code
'err'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-04-10T03:48:35+00:00 Jakub Kicinski kuba@kernel.org 2021-04-10T03:46:01+00:00 8859a44ea0df92bccdc942ef15781ebbfe0ad9f3 Conflicts: MAINTAINERS - keep Chandrasekar drivers/net/ethernet/mellanox/mlx5/core/en_main.c - simple fix + trust the code re-added to param.c in -next is fine include/linux/bpf.h - trivial include/linux/ethtool.h - trivial, fix kdoc while at it include/linux/skmsg.h - move to relevant place in tcp.c, comment re-wrapped net/core/skmsg.c - add the sk = sk // sk = NULL around calls net/tipc/crypto.c - trivial Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Conflicts:

MAINTAINERS
 - keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
 - simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
 - trivial
include/linux/ethtool.h
 - trivial, fix kdoc while at it
include/linux/skmsg.h
 - move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
 - add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
 - trivial

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: report errors for iftoken via netlink extack 2021-04-08T20:52:36+00:00 Stephen Hemminger stephen@networkplumber.org 2021-04-07T15:59:12+00:00 3583a4e8d77d44697a21437227dd53fc6e7b2cb5 Setting iftoken can fail for several different reasons but there and there was no report to user as to the cause. Add netlink extended errors to the processing of the request. This requires adding additional argument through rtnl_af_ops set_link_af callback. Reported-by: Hongren Zheng <li@zenithal.me> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
Setting iftoken can fail for several different reasons but there
and there was no report to user as to the cause. Add netlink
extended errors to the processing of the request.

This requires adding additional argument through rtnl_af_ops
set_link_af callback.

Reported-by: Hongren Zheng <li@zenithal.me>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: remove the new_ifindex argument from dev_change_net_namespace 2021-04-07T21:43:28+00:00 Andrei Vagin avagin@gmail.com 2021-04-07T06:40:51+00:00 0854fa82c96ca37a35e954b7079c0bfd795affb1 Here is only one place where we want to specify new_ifindex. In all other cases, callers pass 0 as new_ifindex. It looks reasonable to add a low-level function with new_ifindex and to convert dev_change_net_namespace to a static inline wrapper. Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace") Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Andrei Vagin <avagin@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
Here is only one place where we want to specify new_ifindex. In all
other cases, callers pass 0 as new_ifindex. It looks reasonable to add a
low-level function with new_ifindex and to convert
dev_change_net_namespace to a static inline wrapper.

Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: introduce nla_policy for IFLA_NEW_IFINDEX 2021-04-07T21:42:12+00:00 Andrei Vagin avagin@gmail.com 2021-04-07T06:40:03+00:00 7e4a51319d3a71ac8002c96f817bcbeb36789b07 In this case, we don't need to check that new_ifindex is positive in validate_linkmsg. Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace") Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Andrei Vagin <avagin@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
In this case, we don't need to check that new_ifindex is positive in
validate_linkmsg.

Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Allow to specify ifindex when device is moved to another namespace 2021-04-05T21:49:40+00:00 Andrei Vagin avagin@gmail.com 2021-04-05T07:12:23+00:00 eeb85a14ee3494febb85ccfbee0772eda0823b13 Currently, we can specify ifindex on link creation. This change allows to specify ifindex when a device is moved to another network namespace. Even now, a device ifindex can be changed if there is another device with the same ifindex in the target namespace. So this change doesn't introduce completely new behavior, it adds more control to the process. CRIU users want to restore containers with pre-created network devices. A user will provide network devices and instructions where they have to be restored, then CRIU will restore network namespaces and move devices into them. The problem is that devices have to be restored with the same indexes that they have before C/R. Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Suggested-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Currently, we can specify ifindex on link creation. This change allows
to specify ifindex when a device is moved to another network namespace.

Even now, a device ifindex can be changed if there is another device
with the same ifindex in the target namespace. So this change doesn't
introduce completely new behavior, it adds more control to the process.

CRIU users want to restore containers with pre-created network devices.
A user will provide network devices and instructions where they have to
be restored, then CRIU will restore network namespaces and move devices
into them. The problem is that devices have to be restored with the same
indexes that they have before C/R.

Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rtnetlink: using dev_base_seq from target net 2021-03-04T00:59:17+00:00 zhang kai zhangkaiheb@126.com 2021-03-02T10:16:07+00:00 a9ecb0cbf03746b17a7c13bd8e3464e6789f73e8 Signed-off-by: zhang kai <zhangkaiheb@126.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: zhang kai <zhangkaiheb@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fix dev_ifsioc_locked() race condition 2021-02-12T02:14:19+00:00 Cong Wang cong.wang@bytedance.com 2021-02-11T19:34:10+00:00 3b23a32a63219f51a5298bc55a65ecee866e79d0 dev_ifsioc_locked() is called with only RCU read lock, so when there is a parallel writer changing the mac address, it could get a partially updated mac address, as shown below: Thread 1 Thread 2 // eth_commit_mac_addr_change() memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); // dev_ifsioc_locked() memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,...); Close this race condition by guarding them with a RW semaphore, like netdev_get_name(). We can not use seqlock here as it does not allow blocking. The writers already take RTNL anyway, so this does not affect the slow path. To avoid bothering existing dev_set_mac_address() callers in drivers, introduce a new wrapper just for user-facing callers on ioctl and rtnetlink paths. Note, bonding also changes slave mac addresses but that requires a separate patch due to the complexity of bonding code. Fixes: 3710becf8a58 ("net: RCU locking for simple ioctl()") Reported-by: "Gong, Sishuai" <sishuai@purdue.edu> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
dev_ifsioc_locked() is called with only RCU read lock, so when
there is a parallel writer changing the mac address, it could
get a partially updated mac address, as shown below:

Thread 1			Thread 2
// eth_commit_mac_addr_change()
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
				// dev_ifsioc_locked()
				memcpy(ifr->ifr_hwaddr.sa_data,
					dev->dev_addr,...);

Close this race condition by guarding them with a RW semaphore,
like netdev_get_name(). We can not use seqlock here as it does not
allow blocking. The writers already take RTNL anyway, so this does
not affect the slow path. To avoid bothering existing
dev_set_mac_address() callers in drivers, introduce a new wrapper
just for user-facing callers on ioctl and rtnetlink paths.

Note, bonding also changes slave mac addresses but that requires
a separate patch due to the complexity of bonding code.

Fixes: 3710becf8a58 ("net: RCU locking for simple ioctl()")
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>