kernel/linux.git/net/ethtool/ioctl.c, branch v7.1-rc5

net, ethtool: Disallow leased real rxqs to be resized

2026-04-10T01:21:46+00:00

Similar to AF_XDP, do not allow queues in a physical netdev to be resized by ethtool -L when they are leased. Cover channel resize paths (both netlink and ioctl) to reject resizing when the queues would be affected. Given we need to have different checks for RX vs TX, detangle the code into a two-loop version rather than the range of new_combined + min(new_rx, new_tx) to old_combined + max(old_rx, old_tx). Signed-off-by: Daniel Borkmann Co-developed-by: David Wei Signed-off-by: David Wei Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260402231031.447597-5-daniel@iogearbox.net Signed-off-by: Jakub Kicinski

ethtool: Track user-provided RSS indirection table size

2026-03-24T00:59:53+00:00

Track the number of indirection table entries the user originally provided (context 0/default as well!). Replace IFF_RXFH_CONFIGURED with rss_indir_user_size: the flag is redundant now that user_size captures the same information. Add ethtool_rxfh_indir_lost() for drivers that must reset the indirection table. Convert bnxt and mlx5 to use it. Signed-off-by: Björn Töpel Link: https://patch.msgid.link/20260320085826.1957255-2-bjorn@kernel.org 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

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ethtool: Avoid overflowing userspace buffer on stats query

2025-12-18T11:24:25+00:00

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

net: ethtool: update set_rxfh_indir to use ethtool_get_rx_ring_count helper

2025-09-18T14:07:38+00:00

Modify ethtool_set_rxfh() to use the new ethtool_get_rx_ring_count() helper function for retrieving the number of RX rings instead of directly calling get_rxnfc with ETHTOOL_GRXRINGS. This way, we can leverage the new helper if it is available in ethtool_ops. Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20250917-gxrings-v4-6-dae520e2e1cb@debian.org Signed-off-by: Jakub Kicinski

net: ethtool: update set_rxfh to use ethtool_get_rx_ring_count helper

2025-09-18T14:07:38+00:00

Modify ethtool_set_rxfh() to use the new ethtool_get_rx_ring_count() helper function for retrieving the number of RX rings instead of directly calling get_rxnfc with ETHTOOL_GRXRINGS. This way, we can leverage the new helper if it is available in ethtool_ops. Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20250917-gxrings-v4-5-dae520e2e1cb@debian.org Signed-off-by: Jakub Kicinski

net: ethtool: add get_rx_ring_count callback to optimize RX ring queries

2025-09-18T14:07:37+00:00

Add a new optional get_rx_ring_count callback in ethtool_ops to allow drivers to provide the number of RX rings directly without going through the full get_rxnfc flow classification interface. Create ethtool_get_rx_ring_count() to use .get_rx_ring_count if available, falling back to get_rxnfc() otherwise. It needs to be non-static, given it will be called by other ethtool functions laters, as those calling get_rxfh(). Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20250917-gxrings-v4-4-dae520e2e1cb@debian.org Signed-off-by: Jakub Kicinski

net: ethtool: remove the duplicated handling from ethtool_get_rxrings

2025-09-18T14:07:37+00:00

ethtool_get_rxrings() was a copy of ethtool_get_rxnfc(). Clean the code that will never be executed for GRXRINGS specifically. Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20250917-gxrings-v4-3-dae520e2e1cb@debian.org Signed-off-by: Jakub Kicinski