kernel/linux.git/net/ethtool, branch v6.6.131

ethtool: Avoid overflowing userspace buffer on stats query

2026-01-11T14:21:47+00:00

[ Upstream commit 7b07be1ff1cb6c49869910518650e8d0abc7d25f ] The ethtool -S command operates across three ioctl calls: ETHTOOL_GSSET_INFO for the size, ETHTOOL_GSTRINGS for the names, and ETHTOOL_GSTATS for the values. If the number of stats changes between these calls (e.g., due to device reconfiguration), userspace's buffer allocation will be incorrect, potentially leading to buffer overflow. Drivers are generally expected to maintain stable stat counts, but some drivers (e.g., mlx5, bnx2x, bna, ksz884x) use dynamic counters, making this scenario possible. Some drivers try to handle this internally: - bnad_get_ethtool_stats() returns early in case stats.n_stats is not equal to the driver's stats count. - micrel/ksz884x also makes sure not to write anything beyond stats.n_stats and overflow the buffer. However, both use stats.n_stats which is already assigned with the value returned from get_sset_count(), hence won't solve the issue described here. Change ethtool_get_strings(), ethtool_get_stats(), ethtool_get_phy_stats() to not return anything in case of a mismatch between userspace's size and get_sset_size(), to prevent buffer overflow. The returned n_stats value will be equal to zero, to reflect that nothing has been returned. This could result in one of two cases when using upstream ethtool, depending on when the size change is detected: 1. When detected in ethtool_get_strings(): # ethtool -S eth2 no stats available 2. When detected in get stats, all stats will be reported as zero. Both cases are presumably transient, and a subsequent ethtool call should succeed. Other than the overflow avoidance, these two cases are very evident (no output/cleared stats), which is arguably better than presenting incorrect/shifted stats. I also considered returning an error instead of a "silent" response, but that seems more destructive towards userspace apps. Notes: - This patch does not claim to fix the inherent race, it only makes sure that we do not overflow the userspace buffer, and makes for a more predictable behavior. - RTNL lock is held during each ioctl, the race window exists between the separate ioctl calls when the lock is released. - Userspace ethtool always fills stats.n_stats, but it is likely that these stats ioctls are implemented in other userspace applications which might not fill it. The added code checks that it's not zero, to prevent any regressions. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Dragos Tatulea Reviewed-by: Tariq Toukan Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20251208121901.3203692-1-gal@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: ethtool: Don't call .cleanup_data when prepare_data fails

2025-04-25T08:45:07+00:00

[ Upstream commit 4f038a6a02d20859a3479293cbf172b0f14cbdd6 ] There's a consistent pattern where the .cleanup_data() callback is called when .prepare_data() fails, when it should really be called to clean after a successful .prepare_data() as per the documentation. Rewrite the error-handling paths to make sure we don't cleanup un-prepared data. Fixes: c781ff12a2f3 ("ethtool: Allow network drivers to dump arbitrary EEPROM data") Reviewed-by: Kory Maincent Reviewed-by: Simon Horman Reviewed-by: Michal Kubecek Signed-off-by: Maxime Chevallier Link: https://patch.msgid.link/20250407130511.75621-1-maxime.chevallier@bootlin.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: avoid race between device unregistration and ethnl ops

2025-02-08T08:52:03+00:00

[ Upstream commit 12e070eb6964b341b41677fd260af5a305316a1f ] The following trace can be seen if a device is being unregistered while its number of channels are being modified. DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 3 PID: 3754 at kernel/locking/mutex.c:564 __mutex_lock+0xc8a/0x1120 CPU: 3 UID: 0 PID: 3754 Comm: ethtool Not tainted 6.13.0-rc6+ #771 RIP: 0010:__mutex_lock+0xc8a/0x1120 Call Trace: ethtool_check_max_channel+0x1ea/0x880 ethnl_set_channels+0x3c3/0xb10 ethnl_default_set_doit+0x306/0x650 genl_family_rcv_msg_doit+0x1e3/0x2c0 genl_rcv_msg+0x432/0x6f0 netlink_rcv_skb+0x13d/0x3b0 genl_rcv+0x28/0x40 netlink_unicast+0x42e/0x720 netlink_sendmsg+0x765/0xc20 __sys_sendto+0x3ac/0x420 __x64_sys_sendto+0xe0/0x1c0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e This is because unregister_netdevice_many_notify might run before the rtnl lock section of ethnl operations, eg. set_channels in the above example. In this example the rss lock would be destroyed by the device unregistration path before being used again, but in general running ethnl operations while dismantle has started is not a good idea. Fix this by denying any operation on devices being unregistered. A check was already there in ethnl_ops_begin, but not wide enough. Note that the same issue cannot be seen on the ioctl version (__dev_ethtool) because the device reference is retrieved from within the rtnl lock section there. Once dismantle started, the net device is unlisted and no reference will be found. Fixes: dde91ccfa25f ("ethtool: do not perform operations on net devices being unregistered") Signed-off-by: Antoine Tenart Reviewed-by: Przemek Kitszel Reviewed-by: Edward Cree Link: https://patch.msgid.link/20250116092159.50890-1-atenart@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ethtool: Fix wrong mod state in case of verbose and no_mask bitset

2024-12-14T18:59:39+00:00

[ Upstream commit 910c4788d6155b2202ec88273376cd7ecdc24f0a ] A bitset without mask in a _SET request means we want exactly the bits in the bitset to be set. This works correctly for compact format but when verbose format is parsed, ethnl_update_bitset32_verbose() only sets the bits present in the request bitset but does not clear the rest. The commit 6699170376ab ("ethtool: fix application of verbose no_mask bitset") fixes this issue by clearing the whole target bitmap before we start iterating. The solution proposed brought an issue with the behavior of the mod variable. As the bitset is always cleared the old value will always differ to the new value. Fix it by adding a new function to compare bitmaps and a temporary variable which save the state of the old bitmap. Fixes: 6699170376ab ("ethtool: fix application of verbose no_mask bitset") Signed-off-by: Kory Maincent Link: https://patch.msgid.link/20241202153358.1142095-1-kory.maincent@bootlin.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ethtool: check device is present when getting link settings

2024-09-04T11:28:26+00:00

[ Upstream commit a699781c79ecf6cfe67fb00a0331b4088c7c8466 ] A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd7fb65 ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17e2d01 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd7fb65 ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ethtool: netlink: do not return SQI value if link is down

2024-07-18T11:21:14+00:00

[ Upstream commit c184cf94e73b04ff7048d045f5413899bc664788 ] Do not attach SQI value if link is down. "SQI values are only valid if link-up condition is present" per OpenAlliance specification of 100Base-T1 Interoperability Test suite [1]. The same rule would apply for other link types. [1] https://opensig.org/automotive-ethernet-specifications/# Fixes: 806602191592 ("ethtool: provide UAPI for PHY Signal Quality Index (SQI)") Signed-off-by: Oleksij Rempel Reviewed-by: Andrew Lunn Reviewed-by: Woojung Huh Link: https://patch.msgid.link/20240709061943.729381-1-o.rempel@pengutronix.de Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: ethtool: fix the error condition in ethtool_get_phy_stats_ethtool()

2024-06-21T12:38:20+00:00

[ Upstream commit 0dcc53abf58d572d34c5313de85f607cd33fc691 ] Clang static checker (scan-build) warning: net/ethtool/ioctl.c:line 2233, column 2 Called function pointer is null (null dereference). Return '-EOPNOTSUPP' when 'ops->get_ethtool_phy_stats' is NULL to fix this typo error. Fixes: 201ed315f967 ("net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers") Signed-off-by: Su Hui Reviewed-by: Przemek Kitszel Reviewed-by: Hariprasad Kelam Link: https://lore.kernel.org/r/20240605034742.921751-1-suhui@nfschina.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

ethtool: netlink: Add missing ethnl_ops_begin/complete

2024-01-25T23:36:00+00:00

[ Upstream commit f1172f3ee3a98754d95b968968920a7d03fdebcc ] Accessing an ethernet device that is powered off or clock gated might cause the CPU to hang. Add ethnl_ops_begin/complete in ethnl_set_features() to protect against this. Fixes: 0980bfcd6954 ("ethtool: set netdev features with FEATURES_SET request") Signed-off-by: Ludvig Pärsson Link: https://lore.kernel.org/r/20240117-etht2-v2-1-1a96b6e8c650@axis.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

ethtool: don't propagate EOPNOTSUPP from dumps

2023-12-08T07:52:23+00:00

[ Upstream commit cbeb989e41f4094f54bec2cecce993f26f547bea ] The default dump handler needs to clear ret before returning. Otherwise if the last interface returns an inconsequential error this error will propagate to user space. This may confuse user space (ethtool CLI seems to ignore it, but YNL doesn't). It will also terminate the dump early for mutli-skb dump, because netlink core treats EOPNOTSUPP as a real error. Fixes: 728480f12442 ("ethtool: default handlers for GET requests") Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20231126225806.2143528-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Revert "ethtool: Fix mod state of verbose no_mask bitset"

2023-10-19T16:27:12+00:00

This reverts commit 108a36d07c01edbc5942d27c92494d1c6e4d45a0. It was reported that this fix breaks the possibility to remove existing WoL flags. For example: ~$ ethtool lan2 ... Supports Wake-on: pg Wake-on: d ... ~$ ethtool -s lan2 wol gp ~$ ethtool lan2 ... Wake-on: pg ... ~$ ethtool -s lan2 wol d ~$ ethtool lan2 ... Wake-on: pg ... This worked correctly before this commit because we were always updating a zero bitmap (since commit 6699170376ab ("ethtool: fix application of verbose no_mask bitset"), that is) so that the rest was left zero naturally. But now the 1->0 change (old_val is true, bit not present in netlink nest) no longer works. Reported-by: Oleksij Rempel Reported-by: Michal Kubecek Closes: https://lore.kernel.org/netdev/20231019095140.l6fffnszraeb6iiw@lion.mk-sys.cz/ Cc: stable@vger.kernel.org Fixes: 108a36d07c01 ("ethtool: Fix mod state of verbose no_mask bitset") Signed-off-by: Kory Maincent Reviewed-by: Michal Kubecek Link: https://lore.kernel.org/r/20231019-feature_ptp_bitset_fix-v1-1-70f3c429a221@bootlin.com Signed-off-by: Jakub Kicinski