linux-stable.git/net/dcb, branch v4.14.331 Linux kernel stable tree net: dcb: disable softirqs in dcbnl_flush_dev() 2022-03-08T18:01:58+00:00 Vladimir Oltean vladimir.oltean@nxp.com 2022-03-02T19:39:39+00:00 3210dd5bcea96769c53f8c1f5e15aeb915999e36 commit 10b6bb62ae1a49ee818fc479cf57b8900176773e upstream. Ido Schimmel points out that since commit 52cff74eef5d ("dcbnl : Disable software interrupts before taking dcb_lock"), the DCB API can be called by drivers from softirq context. One such in-tree example is the chelsio cxgb4 driver: dcb_rpl -> cxgb4_dcb_handle_fw_update -> dcb_ieee_setapp If the firmware for this driver happened to send an event which resulted in a call to dcb_ieee_setapp() at the exact same time as another DCB-enabled interface was unregistering on the same CPU, the softirq would deadlock, because the interrupted process was already holding the dcb_lock in dcbnl_flush_dev(). Fix this unlikely event by using spin_lock_bh() in dcbnl_flush_dev() as in the rest of the dcbnl code. Fixes: 91b0383fef06 ("net: dcb: flush lingering app table entries for unregistered devices") Reported-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20220302193939.1368823-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 10b6bb62ae1a49ee818fc479cf57b8900176773e upstream.

Ido Schimmel points out that since commit 52cff74eef5d ("dcbnl : Disable
software interrupts before taking dcb_lock"), the DCB API can be called
by drivers from softirq context.

One such in-tree example is the chelsio cxgb4 driver:
dcb_rpl
-> cxgb4_dcb_handle_fw_update
   -> dcb_ieee_setapp

If the firmware for this driver happened to send an event which resulted
in a call to dcb_ieee_setapp() at the exact same time as another
DCB-enabled interface was unregistering on the same CPU, the softirq
would deadlock, because the interrupted process was already holding the
dcb_lock in dcbnl_flush_dev().

Fix this unlikely event by using spin_lock_bh() in dcbnl_flush_dev() as
in the rest of the dcbnl code.

Fixes: 91b0383fef06 ("net: dcb: flush lingering app table entries for unregistered devices")
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220302193939.1368823-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dcb: flush lingering app table entries for unregistered devices 2022-03-08T18:01:57+00:00 Vladimir Oltean vladimir.oltean@nxp.com 2022-02-24T16:01:54+00:00 5950e969812e59d71fa880f14d3229c4572d9d46 commit 91b0383fef06f20b847fa9e4f0e3054ead0b1a1b upstream. If I'm not mistaken (and I don't think I am), the way in which the dcbnl_ops work is that drivers call dcb_ieee_setapp() and this populates the application table with dynamically allocated struct dcb_app_type entries that are kept in the module-global dcb_app_list. However, nobody keeps exact track of these entries, and although dcb_ieee_delapp() is supposed to remove them, nobody does so when the interface goes away (example: driver unbinds from device). So the dcb_app_list will contain lingering entries with an ifindex that no longer matches any device in dcb_app_lookup(). Reclaim the lost memory by listening for the NETDEV_UNREGISTER event and flushing the app table entries of interfaces that are now gone. In fact something like this used to be done as part of the initial commit (blamed below), but it was done in dcbnl_exit() -> dcb_flushapp(), essentially at module_exit time. That became dead code after commit 7a6b6f515f77 ("DCB: fix kconfig option") which essentially merged "tristate config DCB" and "bool config DCBNL" into a single "bool config DCB", so net/dcb/dcbnl.c could not be built as a module anymore. Commit 36b9ad8084bd ("net/dcb: make dcbnl.c explicitly non-modular") recognized this and deleted dcbnl_exit() and dcb_flushapp() altogether, leaving us with the version we have today. Since flushing application table entries can and should be done as soon as the netdevice disappears, fundamentally the commit that is to blame is the one that introduced the design of this API. Fixes: 9ab933ab2cc8 ("dcbnl: add appliction tlv handlers") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 91b0383fef06f20b847fa9e4f0e3054ead0b1a1b upstream.

If I'm not mistaken (and I don't think I am), the way in which the
dcbnl_ops work is that drivers call dcb_ieee_setapp() and this populates
the application table with dynamically allocated struct dcb_app_type
entries that are kept in the module-global dcb_app_list.

However, nobody keeps exact track of these entries, and although
dcb_ieee_delapp() is supposed to remove them, nobody does so when the
interface goes away (example: driver unbinds from device). So the
dcb_app_list will contain lingering entries with an ifindex that no
longer matches any device in dcb_app_lookup().

Reclaim the lost memory by listening for the NETDEV_UNREGISTER event and
flushing the app table entries of interfaces that are now gone.

In fact something like this used to be done as part of the initial
commit (blamed below), but it was done in dcbnl_exit() -> dcb_flushapp(),
essentially at module_exit time. That became dead code after commit
7a6b6f515f77 ("DCB: fix kconfig option") which essentially merged
"tristate config DCB" and "bool config DCBNL" into a single "bool config
DCB", so net/dcb/dcbnl.c could not be built as a module anymore.

Commit 36b9ad8084bd ("net/dcb: make dcbnl.c explicitly non-modular")
recognized this and deleted dcbnl_exit() and dcb_flushapp() altogether,
leaving us with the version we have today.

Since flushing application table entries can and should be done as soon
as the netdevice disappears, fundamentally the commit that is to blame
is the one that introduced the design of this API.

Fixes: 9ab933ab2cc8 ("dcbnl: add appliction tlv handlers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dcb: Accept RTM_GETDCB messages carrying set-like DCB commands 2021-01-23T14:48:46+00:00 Petr Machata petrm@nvidia.com 2021-01-11T17:07:07+00:00 faebcfeba362a183d3cbc984fd0119249de5cda6 [ Upstream commit df85bc140a4d6cbaa78d8e9c35154e1a2f0622c7 ] In commit 826f328e2b7e ("net: dcb: Validate netlink message in DCB handler"), Linux started rejecting RTM_GETDCB netlink messages if they contained a set-like DCB_CMD_ command. The reason was that privileges were only verified for RTM_SETDCB messages, but the value that determined the action to be taken is the command, not the message type. And validation of message type against the DCB command was the obvious missing piece. Unfortunately it turns out that mlnx_qos, a somewhat widely deployed tool for configuration of DCB, accesses the DCB set-like APIs through RTM_GETDCB. Therefore do not bounce the discrepancy between message type and command. Instead, in addition to validating privileges based on the actual message type, validate them also based on the expected message type. This closes the loophole of allowing DCB configuration on non-admin accounts, while maintaining backward compatibility. Fixes: 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver") Fixes: 826f328e2b7e ("net: dcb: Validate netlink message in DCB handler") Signed-off-by: Petr Machata <petrm@nvidia.com> Link: https://lore.kernel.org/r/a3edcfda0825f2aa2591801c5232f2bbf2d8a554.1610384801.git.me@pmachata.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit df85bc140a4d6cbaa78d8e9c35154e1a2f0622c7 ]

In commit 826f328e2b7e ("net: dcb: Validate netlink message in DCB
handler"), Linux started rejecting RTM_GETDCB netlink messages if they
contained a set-like DCB_CMD_ command.

The reason was that privileges were only verified for RTM_SETDCB messages,
but the value that determined the action to be taken is the command, not
the message type. And validation of message type against the DCB command
was the obvious missing piece.

Unfortunately it turns out that mlnx_qos, a somewhat widely deployed tool
for configuration of DCB, accesses the DCB set-like APIs through
RTM_GETDCB.

Therefore do not bounce the discrepancy between message type and command.
Instead, in addition to validating privileges based on the actual message
type, validate them also based on the expected message type. This closes
the loophole of allowing DCB configuration on non-admin accounts, while
maintaining backward compatibility.

Fixes: 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver")
Fixes: 826f328e2b7e ("net: dcb: Validate netlink message in DCB handler")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/a3edcfda0825f2aa2591801c5232f2bbf2d8a554.1610384801.git.me@pmachata.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dcb: Validate netlink message in DCB handler 2021-01-23T14:48:46+00:00 Petr Machata me@pmachata.org 2020-12-22T21:49:44+00:00 9591d6a21f402237b980c943a4b6895aed4c84a5 [ Upstream commit 826f328e2b7e8854dd42ea44e6519cd75018e7b1 ] DCB uses the same handler function for both RTM_GETDCB and RTM_SETDCB messages. dcb_doit() bounces RTM_SETDCB mesasges if the user does not have the CAP_NET_ADMIN capability. However, the operation to be performed is not decided from the DCB message type, but from the DCB command. Thus DCB_CMD_*_GET commands are used for reading DCB objects, the corresponding SET and DEL commands are used for manipulation. The assumption is that set-like commands will be sent via an RTM_SETDCB message, and get-like ones via RTM_GETDCB. However, this assumption is not enforced. It is therefore possible to manipulate DCB objects without CAP_NET_ADMIN capability by sending the corresponding command in an RTM_GETDCB message. That is a bug. Fix it by validating the type of the request message against the type used for the response. Fixes: 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver") Signed-off-by: Petr Machata <me@pmachata.org> Link: https://lore.kernel.org/r/a2a9b88418f3a58ef211b718f2970128ef9e3793.1608673640.git.me@pmachata.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 826f328e2b7e8854dd42ea44e6519cd75018e7b1 ]

DCB uses the same handler function for both RTM_GETDCB and RTM_SETDCB
messages. dcb_doit() bounces RTM_SETDCB mesasges if the user does not have
the CAP_NET_ADMIN capability.

However, the operation to be performed is not decided from the DCB message
type, but from the DCB command. Thus DCB_CMD_*_GET commands are used for
reading DCB objects, the corresponding SET and DEL commands are used for
manipulation.

The assumption is that set-like commands will be sent via an RTM_SETDCB
message, and get-like ones via RTM_GETDCB. However, this assumption is not
enforced.

It is therefore possible to manipulate DCB objects without CAP_NET_ADMIN
capability by sending the corresponding command in an RTM_GETDCB message.
That is a bug. Fix it by validating the type of the request message against
the type used for the response.

Fixes: 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver")
Signed-off-by: Petr Machata <me@pmachata.org>
Link: https://lore.kernel.org/r/a2a9b88418f3a58ef211b718f2970128ef9e3793.1608673640.git.me@pmachata.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: dcb: For wild-card lookups, use priority -1, not 0 2018-09-19T20:43:43+00:00 Petr Machata petrm@mellanox.com 2018-07-27T12:26:55+00:00 94f885db2a18b9c6d36b31f1f4af7c1c820fac60 [ Upstream commit 08193d1a893c802c4b807e4d522865061f4e9f4f ] The function dcb_app_lookup walks the list of specified DCB APP entries, looking for one that matches a given criteria: ifindex, selector, protocol ID and optionally also priority. The "don't care" value for priority is set to 0, because that priority has not been allowed under CEE regime, which predates the IEEE standardization. Under IEEE, 0 is a valid priority number. But because dcb_app_lookup considers zero a wild card, attempts to add an APP entry with priority 0 fail when other entries exist for a given ifindex / selector / PID triplet. Fix by changing the wild-card value to -1. Signed-off-by: Petr Machata <petrm@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 08193d1a893c802c4b807e4d522865061f4e9f4f ]

The function dcb_app_lookup walks the list of specified DCB APP entries,
looking for one that matches a given criteria: ifindex, selector,
protocol ID and optionally also priority. The "don't care" value for
priority is set to 0, because that priority has not been allowed under
CEE regime, which predates the IEEE standardization.

Under IEEE, 0 is a valid priority number. But because dcb_app_lookup
considers zero a wild card, attempts to add an APP entry with priority 0
fail when other entries exist for a given ifindex / selector / PID
triplet.

Fix by changing the wild-card value to -1.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rtnetlink: make rtnl_register accept a flags parameter 2017-08-09T23:57:38+00:00 Florian Westphal fw@strlen.de 2017-08-09T18:41:48+00:00 b97bac64a589d0158cf866e8995e831030f68f4f This change allows us to later indicate to rtnetlink core that certain doit functions should be called without acquiring rtnl_mutex. This change should have no effect, we simply replace the last (now unused) calcit argument with the new flag. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
This change allows us to later indicate to rtnetlink core that certain
doit functions should be called without acquiring rtnl_mutex.

This change should have no effect, we simply replace the last (now
unused) calcit argument with the new flag.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
dcb: enforce minimum length on IEEE_APPS attribute 2017-05-21T17:42:33+00:00 stephen hemminger stephen@networkplumber.org 2017-05-19T16:55:48+00:00 332b4fc88698dd0429924a61e09d1734940d80a0 Found by reviewing the warning about unused policy table. The code implies that it meant to check for size, but since it unrolled the loop for attribute validation that is never used. Instead do explicit check for attribute. Compile tested only. Needs review by original author. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Found by reviewing the warning about unused policy table.
The code implies that it meant to check for size, but since
it unrolled the loop for attribute validation that is never used.
Instead do explicit check for attribute.

Compile tested only. Needs review by original author.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: rtnetlink: plumb extended ack to doit function 2017-04-17T19:35:38+00:00 David Ahern dsa@cumulusnetworks.com 2017-04-16T16:48:24+00:00 c21ef3e343ae916ad3cfd4dc6ef6791c1f80a010 Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse for doit functions that call it directly. This is the first step to using extended error reporting in rtnetlink. >From here individual subsystems can be updated to set netlink_ext_ack as needed. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
for doit functions that call it directly.

This is the first step to using extended error reporting in rtnetlink.
>From here individual subsystems can be updated to set netlink_ext_ack as
needed.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: pass extended ACK struct to parsing functions 2017-04-13T17:58:22+00:00 Johannes Berg johannes.berg@intel.com 2017-04-12T12:34:07+00:00 fceb6435e85298f747fee938415057af837f5a8a Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: dcb: set error code on failures 2016-12-04T04:54:25+00:00 Pan Bian bianpan2016@163.com 2016-12-03T13:49:08+00:00 c66ebf2db555c6ed705044eabd2b37dcd546f68b In function dcbnl_cee_fill(), returns the value of variable err on errors. However, on some error paths (e.g. nla put fails), its value may be 0. It may be better to explicitly set a negative errno to variable err before returning. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188881 Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In function dcbnl_cee_fill(), returns the value of variable err on
errors. However, on some error paths (e.g. nla put fails), its value may
be 0. It may be better to explicitly set a negative errno to variable
err before returning.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188881

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>