linux.git/net/ethtool/strset.c, branch v7.1-rc4

ethtool: strset: check nla_len overflow

2026-04-12T18:23:50+00:00

The netlink attribute length field nla_len is a __u16, which can only
represent values up to 65535 bytes. NICs with a large number of
statistics strings (e.g. mlx5_core with thousands of ETH_SS_STATS
entries) can produce a ETHTOOL_A_STRINGSET_STRINGS nest that exceeds
this limit.

When nla_nest_end() writes the actual nest size back to nla_len, the
value is silently truncated. This results in a corrupted netlink message
being sent to userspace: the parser reads a wrong (truncated) attribute
length and misaligns all subsequent attribute boundaries, causing decode
errors.

Fix this by using the new helper nla_nest_end_safe and error out if
the size exceeds U16_MAX.

Signed-off-by: Hangbin Liu 
Link: https://patch.msgid.link/20260408-b4-ynl_ethtool-v2-5-7623a5e8f70b@gmail.com
Signed-off-by: Jakub Kicinski

net: ethtool: pass genl_info to the ethnl parse_request operation

2026-03-25T03:14:29+00:00

The .parse_request() ethnl operation extracts the relevant attributes
from the netlink request to populate the private req_info.

By passing genl_info as a parameter to this callback, we can use
the GENL_REQ_ATTR_CHECK() macro to check for missing mandatory
parameters.

This macro has the advantage of returning a better error explanation
through the netlink_ext_ack struct.

Convert the eeprom ethnl code to this macro, as it's the only command
yet that has mandatory request parameters.

Suggested-by: Jakub Kicinski 
Signed-off-by: Maxime Chevallier 
Link: https://patch.msgid.link/20260323095833.136266-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski

net: ethtool: re-order local includes

2026-03-21T02:10:18+00:00

Most local #include in the ethtool command handling is out of order,
with either :

 #include "netlink.h"
 #include "common.h"

or even :

 #include "netlink.h"
 #include "common.h"
 #include "bitset.h"

One of the reasons is because bitset.h s lacking definitions for
nlattr, netlink_ext_ack, ETH_GSTRING_LEN, and types such as u32, bool,
etc.

Make bitset.h standalone by including  for
ETH_GSTRING_LEN, and  for nlattr, netlink_ext_ack and
the rest.

While at it, take a pass on ethnl sources to re-order the local
includes :
 - put them after the global includes
 - add a newline between global and local includes
 - alpha-sort the local includes

One notable exception is the cmis.h include, that needs definitions from
module_fw.h. Keep them in this order for now.

Signed-off-by: Maxime Chevallier 
Link: https://patch.msgid.link/20260319180555.1531386-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski

net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device

2025-03-05T01:12:01+00:00

ethnl_req_get_phydev() is used to lookup a phy_device, in the case an
ethtool netlink command targets a specific phydev within a netdev's
topology.

It takes as a parameter a const struct nlattr *header that's used for
error handling :

       if (!phydev) {
               NL_SET_ERR_MSG_ATTR(extack, header,
                                   "no phy matching phyindex");
               return ERR_PTR(-ENODEV);
       }

In the notify path after a ->set operation however, there's no request
attributes available.

The typical callsite for the above function looks like:

	phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_XXX_HEADER],
				      info->extack);

So, when tb is NULL (such as in the ethnl notify path), we have a nice
crash.

It turns out that there's only the PLCA command that is in that case, as
the other phydev-specific commands don't have a notification.

This commit fixes the crash by passing the cmd index and the nlattr
array separately, allowing NULL-checking it directly inside the helper.

Fixes: c15e065b46dc ("net: ethtool: Allow passing a phy index for some commands")
Signed-off-by: Maxime Chevallier 
Reviewed-by: Kory Maincent 
Reported-by: Parthiban Veerasooran 
Link: https://patch.msgid.link/20250301141114.97204-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski

net: ethtool: tsconfig: Fix netlink type of hwtstamp flags

2025-02-07T00:35:21+00:00

Fix the netlink type for hardware timestamp flags, which are represented
as a bitset of flags. Although only one flag is supported currently, the
correct netlink bitset type should be used instead of u32 to keep
consistency with other fields. Address this by adding a new named string
set description for the hwtstamp flag structure.

The code has been introduced in the current release so the uAPI change is
still okay.

Signed-off-by: Kory Maincent 
Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config")
Link: https://patch.msgid.link/20250205110304.375086-1-kory.maincent@bootlin.com
Signed-off-by: Jakub Kicinski

net: ethtool: add support for structured PHY statistics

2025-01-14T10:44:19+00:00

Introduce a new way to report PHY statistics in a structured and
standardized format using the netlink API. This new method does not
replace the old driver-specific stats, which can still be accessed with
`ethtool -S `. The structured stats are available with
`ethtool -S  --all-groups`.

This new method makes it easier to diagnose problems by organizing stats
in a consistent and documented way.

Signed-off-by: Jakub Kicinski 
Signed-off-by: Oleksij Rempel 
Signed-off-by: Paolo Abeni

net: ethtool: strset: Allow querying phy stats by index

2024-08-23T12:04:35+00:00

The ETH_SS_PHY_STATS command gets PHY statistics. Use the phydev pointer
from the ethnl request to allow query phy stats from each PHY on the
link.

Signed-off-by: Maxime Chevallier 
Reviewed-by: Christophe Leroy 
Tested-by: Christophe Leroy 
Signed-off-by: David S. Miller

ethtool: Don't check for NULL info in prepare_data callbacks

2024-08-01T16:03:52+00:00

Since commit f946270d05c2 ("ethtool: netlink: always pass genl_info to
.prepare_data") the info argument of prepare_data callbacks is never
NULL. Remove checks present in callback implementations.

Link: https://lore.kernel.org/netdev/20240703121237.3f8b9125@kernel.org/
Signed-off-by: Simon Horman 
Link: https://patch.msgid.link/20240731-prepare_data-null-check-v1-1-627f2320678f@kernel.org
Signed-off-by: Jakub Kicinski

ethtool: netlink: always pass genl_info to .prepare_data

2023-08-15T22:01:03+00:00

We had a number of bugs in the past because developers forgot
to fully test dumps, which pass NULL as info to .prepare_data.
.prepare_data implementations would try to access info->extack
leading to a null-deref.

Now that dumps and notifications can access struct genl_info
we can pass it in, and remove the info null checks.

Reviewed-by: Vladimir Oltean 
Tested-by: Vladimir Oltean  # pause
Reviewed-by: Jiri Pirko 
Link: https://lore.kernel.org/r/20230814214723.2924989-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski

ethtool: strset: report missing ETHTOOL_A_STRINGSET_ID via ext_ack

2022-08-30T10:20:43+00:00

Strset needs ETHTOOL_A_STRINGSET_ID, use it as an example of
reporting attrs missing in nests.

Reviewed-by: Johannes Berg 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Paolo Abeni