kernel/linux.git/net/ethtool/ioctl.c, branch v6.12.80

ethtool: Avoid overflowing userspace buffer on stats query

2026-01-08T09:14:02+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

ethtool: ntuple: fix rss + ring_cookie check

2025-02-08T08:58:19+00:00

commit 2b91cc1214b165c25ac9b0885db89a0d3224028a upstream. The info.flow_type is for RXFH commands, ntuple flow_type is inside the flow spec. The check currently does nothing, as info.flow_type is 0 (or even uninitialized by user space) for ETHTOOL_SRXCLSRLINS. Fixes: 9e43ad7a1ede ("net: ethtool: only allow set_rxnfc with rss + ring_cookie if driver opts in") Reviewed-by: Gal Pressman Reviewed-by: Joe Damato Link: https://patch.msgid.link/20250201013040.725123-3-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ethtool: Fix access to uninitialized fields in set RXNFC command

2025-02-08T08:58:18+00:00

commit 94071909477677fc2a1abf3fb281f203f66cf3ca upstream. The check for non-zero ring with RSS is only relevant for ETHTOOL_SRXCLSRLINS command, in other cases the check tries to access memory which was not initialized by the userspace tool. Only perform the check in case of ETHTOOL_SRXCLSRLINS. Without this patch, filter deletion (for example) could statistically result in a false error: # ethtool --config-ntuple eth3 delete 484 rmgr: Cannot delete RX class rule: Invalid argument Cannot delete classification rule Fixes: 9e43ad7a1ede ("net: ethtool: only allow set_rxnfc with rss + ring_cookie if driver opts in") Link: https://lore.kernel.org/netdev/871a9ecf-1e14-40dd-bbd7-e90c92f89d47@nvidia.com/ Reviewed-by: Dragos Tatulea Reviewed-by: Tariq Toukan Signed-off-by: Gal Pressman Reviewed-by: Edward Cree Link: https://patch.msgid.link/20241202164805.1637093-1-gal@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ethtool: Fix set RXNFC command with symmetric RSS hash

2025-02-08T08:58:06+00:00

[ Upstream commit 4f5a52adeb1ad675ca33f1e1eacd9c0bbaf393d4 ] The sanity check that both source and destination are set when symmetric RSS hash is requested is only relevant for ETHTOOL_SRXFH (rx-flow-hash), it should not be performed on any other commands (e.g. ETHTOOL_SRXCLSRLINS/ETHTOOL_SRXCLSRLDEL). This resolves accessing uninitialized 'info.data' field, and fixes false errors in rule insertion: # ethtool --config-ntuple eth2 flow-type ip4 dst-ip 255.255.255.255 action -1 loc 0 rmgr: Cannot insert RX class rule: Invalid argument Cannot insert classification rule Fixes: 13e59344fb9d ("net: ethtool: add support for symmetric-xor RSS hash") Cc: Ahmed Zaki Reviewed-by: Tariq Toukan Signed-off-by: Gal Pressman Reviewed-by: Michal Swiatkowski Reviewed-by: Edward Cree Reviewed-by: Ahmed Zaki Link: https://patch.msgid.link/20250126191845.316589-1-gal@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: ethtool: only allow set_rxnfc with rss + ring_cookie if driver opts in

2025-02-08T08:58:06+00:00

[ Upstream commit 9e43ad7a1edef268acac603e1975c8f50a20d02f ] Ethtool ntuple filters with FLOW_RSS were originally defined as adding the base queue ID (ring_cookie) to the value from the indirection table, so that the same table could distribute over more than one set of queues when used by different filters. However, some drivers / hardware ignore the ring_cookie, and simply use the indirection table entries as queue IDs directly. Thus, for drivers which have not opted in by setting ethtool_ops.cap_rss_rxnfc_adds to declare that they support the original (addition) semantics, reject in ethtool_set_rxnfc any filter which combines FLOW_RSS and a nonzero ring. (For a ring_cookie of zero, both behaviours are equivalent.) Set the cap bit in sfc, as it is known to support this feature. Signed-off-by: Edward Cree Reviewed-by: Martin Habets Link: https://patch.msgid.link/cc3da0844083b0e301a33092a6299e4042b65221.1731499022.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski Stable-dep-of: 4f5a52adeb1a ("ethtool: Fix set RXNFC command with symmetric RSS hash") Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-08-29T18:49:10+00:00

Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/faraday/ftgmac100.c 4186c8d9e6af ("net: ftgmac100: Ensure tx descriptor updates are visible") e24a6c874601 ("net: ftgmac100: Get link speed and duplex for NC-SI") https://lore.kernel.org/0b851ec5-f91d-4dd3-99da-e81b98c9ed28@kernel.org net/ipv4/tcp.c bac76cf89816 ("tcp: fix forever orphan socket caused by tcp_abort") edefba66d929 ("tcp: rstreason: introduce SK_RST_REASON_TCP_STATE for active reset") https://lore.kernel.org/20240828112207.5c199d41@canb.auug.org.au No adjacent changes. Link: https://patch.msgid.link/20240829130829.39148-1-pabeni@redhat.com Signed-off-by: Jakub Kicinski

ethtool: check device is present when getting link settings

2024-08-26T21:03:02+00:00

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

ethtool: rss: don't report key if device doesn't support it

2024-08-12T13:16:24+00:00

marvell/otx2 and mvpp2 do not support setting different keys for different RSS contexts. Contexts have separate indirection tables but key is shared with all other contexts. This is likely fine, indirection table is the most important piece. Don't report the key-related parameters from such drivers. This prevents driver-errors, e.g. otx2 always writes the main key, even when user asks to change per-context key. The second reason is that without this change tracking the keys by the core gets complicated. Even if the driver correctly reject setting key with rss_context != 0, change of the main key would have to be reflected in the XArray for all additional contexts. Since the additional contexts don't have their own keys not including the attributes (in Netlink speak) seems intuitive. ethtool CLI seems to deal with it just fine. Having to set the flag in majority of the drivers is a bit tedious but not reporting the key is a safer default. Reviewed-by: Edward Cree Reviewed-by: Joe Damato Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

ethtool: make ethtool_ops::cap_rss_ctx_supported optional

2024-08-12T13:16:24+00:00

cap_rss_ctx_supported was created because the API for creating and configuring additional contexts is mux'ed with the normal RSS API. Presence of ops does not imply driver can actually support rss_context != 0 (in fact drivers mostly ignore that field). cap_rss_ctx_supported lets core check that the driver is context-aware before calling it. Now that we have .create_rxfh_context, there is no such ambiguity. We can depend on presence of the op. Make setting the bit optional. Reviewed-by: Gal Pressman Reviewed-by: Edward Cree Reviewed-by: Joe Damato Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

ethtool: refactor checking max channels

2024-08-10T04:52:13+00:00

Currently ethtool_set_channel calls separate functions to check whether the new channel number violates rss configuration or flow steering configuration. Very soon we need to check whether the new channel number violates memory provider configuration as well. To do all 3 checks cleanly, add a wrapper around ethtool_get_max_rxnfc_channel() and ethtool_get_max_rxfh_channel(), which does both checks. We can later extend this wrapper to add the memory provider check in one place. Note that in the current code, we put a descriptive genl error message when we run into issues. To preserve the error message, we pass the genl_info* to the common helper. The ioctl calls can pass NULL instead. Suggested-by: Jakub Kicinski Signed-off-by: Mina Almasry Link: https://patch.msgid.link/20240808205345.2141858-1-almasrymina@google.com Signed-off-by: Jakub Kicinski