kernel/linux.git/Documentation/networking, branch master

Merge tag 'net-deletions' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2026-04-24T16:41:58+00:00

Pull networking deletions from Jakub Kicinski: "Delete some obsolete networking code Old code like amateur radio and NFC have long been a burden to core networking developers. syzbot loves to find bugs in BKL-era code, and noobs try to fix them. If we want to have a fighting chance of surviving the LLM-pocalypse this code needs to find a dedicated owner or get deleted. We've talked about these deletions multiple times in the past and every time someone wanted the code to stay. It is never very clear to me how many of those people actually use the code vs are just nostalgic to see it go. Amateur radio did have occasional users (or so I think) but most users switched to user space implementations since its all super slow stuff. Nobody stepped up to maintain the kernel code. We were lucky enough to find someone who wants to help with NFC so we're giving that a chance. Let's try to put the rest of this code behind us" * tag 'net-deletions' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: drivers: net: 8390: wd80x3: Remove this driver drivers: net: 8390: ultra: Remove this driver drivers: net: 8390: AX88190: Remove this driver drivers: net: fujitsu: fmvj18x: Remove this driver drivers: net: smsc: smc91c92: Remove this driver drivers: net: smsc: smc9194: Remove this driver drivers: net: amd: nmclan: Remove this driver drivers: net: amd: lance: Remove this driver drivers: net: 3com: 3c589: Remove this driver drivers: net: 3com: 3c574: Remove this driver drivers: net: 3com: 3c515: Remove this driver drivers: net: 3com: 3c509: Remove this driver net: packetengines: remove obsolete yellowfin driver and vendor dir net: packetengines: remove obsolete hamachi driver net: remove unused ATM protocols and legacy ATM device drivers net: remove ax25 and amateur radio (hamradio) subsystem net: remove ISDN subsystem and Bluetooth CMTP caif: remove CAIF NETWORK LAYER

drivers: net: smsc: smc91c92: Remove this driver

2026-04-23T22:57:06+00:00

The smc91c92 was written by David A Hinds in 1999. It is an PCMCIA device, so unlikely to be used with modern kernels. Remove the Documentation as well, since it refers to kernel versions 1.2.13 until 1.3.71 and FTP sites which no longer exist. Signed-off-by: Andrew Lunn Link: https://patch.msgid.link/20260422-v7-0-0-net-next-driver-removal-v1-v2-8-08a5b59784d5@lunn.ch Signed-off-by: Jakub Kicinski

drivers: net: 3com: 3c509: Remove this driver

2026-04-23T22:56:43+00:00

The 3c509 was written by Donald Becker between 1993-2000. It is an ISA device, so unlikely to be used with modern kernels. Signed-off-by: Andrew Lunn Link: https://patch.msgid.link/20260422-v7-0-0-net-next-driver-removal-v1-v2-1-08a5b59784d5@lunn.ch Signed-off-by: Jakub Kicinski

net: remove unused ATM protocols and legacy ATM device drivers

2026-04-23T19:21:14+00:00

Remove the ATM protocol modules and PCI/SBUS ATM device drivers that are no longer in active use. The ATM core protocol stack, PPPoATM, BR2684, and USB DSL modem drivers (drivers/usb/atm/) are retained in-tree to maintain PPP over ATM (PPPoA) and PPPoE-over-BR2684 support for DSL connections. The Solos ADSL2+ PCI driver is also retained. Removed ATM protocol modules: - net/atm/clip.c - Classical IP over ATM (RFC 2225) - net/atm/lec.c - LAN Emulation Client (LANE) - net/atm/mpc.c, mpoa_caches.c, mpoa_proc.c - Multi-Protocol Over ATM Removed PCI/SBUS ATM device drivers (drivers/atm/): - adummy, atmtcp - software/testing ATM devices - eni - Efficient Networks ENI155P (OC-3, ~1995) - fore200e - FORE Systems 200E PCI/SBUS (OC-3, ~1999) - he - ForeRunner HE (OC-3/OC-12, ~2000) - idt77105 - IDT 77105 25 Mbps ATM PHY - idt77252 - IDT 77252 NICStAR II (OC-3, ~2000) - iphase - Interphase ATM PCI (OC-3/DS3/E3) - lanai - Efficient Networks Speedstream 3010 - nicstar - IDT 77201 NICStAR (155/25 Mbps, ~1999) - suni - PMC S/UNI SONET PHY library Also clean up references in: - net/bridge/ - remove ATM LANE hook (br_fdb_test_addr_hook, br_fdb_test_addr) - net/core/dev.c - remove br_fdb_test_addr_hook export - defconfig files - remove ATM driver config options The removed code is moved to an out-of-tree module package (mod-orphan). Acked-by: Andy Shevchenko Reviewed-by: Simon Horman Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260422041846.2035118-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: remove ax25 and amateur radio (hamradio) subsystem

2026-04-23T17:24:02+00:00

Remove the amateur radio (AX.25, NET/ROM, ROSE) protocol implementation and all associated hamradio device drivers from the kernel tree. This set of protocols has long been a huge bug/syzbot magnet, and since nobody stepped up to help us deal with the influx of the AI-generated bug reports we need to move it out of tree to protect our sanity. The code is moved to an out-of-tree repo: https://github.com/linux-netdev/mod-orphan if it's cleaned up and reworked there we can accept it back. Minimal stub headers are kept for include/net/ax25.h (AX25_P_IP, AX25_ADDR_LEN, ax25_address) and include/net/rose.h (ROSE_ADDR_LEN) so that the conditional integration code in arp.c and tun.c continues to compile and work when the out-of-tree modules are loaded. Signed-off-by: Jakub Kicinski Acked-by: Greg Kroah-Hartman Acked-by: Stephen Hemminger Acked-by: Carlos Bilbao Reviewed-by: Simon Horman Reviewed-by: Kuniyuki Iwashima Acked-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20260421021824.1293976-1-kuba@kernel.org Signed-off-by: Paolo Abeni

caif: remove CAIF NETWORK LAYER

2026-04-23T17:23:44+00:00

Remove CAIF (Communication CPU to Application CPU Interface), the ST-Ericsson modem protocol. The subsystem has been orphaned since 2013. The last meaningful changes from the maintainers were in March 2013: a8c7687bf216 ("caif_virtio: Check that vringh_config is not null") b2273be8d2df ("caif_virtio: Use vringh_notify_enable correctly") 0d2e1a2926b1 ("caif_virtio: Introduce caif over virtio") Not-so-coincidentally, according to "the Internet" ST-Ericsson officially shut down its modem joint venture in Aug 2013. If anyone is using this code please yell! In the 13 years since, the code has accumulated 200 non-merge commits, of which 71 were cross-tree API changes, 21 carried Fixes: tags, and the remaining ~110 were cleanups, doc conversions, treewide refactors, and one partial removal (caif_hsi, ca75bcf0a83b). We are still getting fixes to this code, in the last 10 days there were 3 reports on security@ about CAIF that I have been CCed on. UAPI constants (AF_CAIF, ARPHRD_CAIF, N_CAIF, VIRTIO_ID_CAIF) and the SELinux classmap entry are intentionally kept for ABI stability. Acked-by: Michael S. Tsirkin Acked-by: Greg Kroah-Hartman Reviewed-by: Linus Walleij Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260416182829.1440262-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: move promiscuity handling into netdev_rx_mode_work

2026-04-21T10:50:24+00:00

Move unicast promiscuity tracking into netdev_rx_mode_work so it runs under netdev_ops_lock instead of under the addr_lock spinlock. This is required because __dev_set_promiscuity calls dev_change_rx_flags and __dev_notify_flags, both of which may need to sleep. Change ASSERT_RTNL() to netdev_ops_assert_locked() in __dev_set_promiscuity, netif_set_allmulti and __dev_change_flags since these are now called from the work queue under the ops lock. Link: https://lore.kernel.org/netdev/20260214033859.43857-1-jiayuan.chen@linux.dev/ Fixes: 78cd408356fe ("net: add missing instance lock to dev_set_promiscuity") Reported-by: syzbot+2b3391f44313b3983e91@syzkaller.appspotmail.com Reviewed-by: Aleksandr Loktionov Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260416185712.2155425-5-sdf@fomichev.me Signed-off-by: Paolo Abeni

net: introduce ndo_set_rx_mode_async and netdev_rx_mode_work

2026-04-21T10:50:03+00:00

Add ndo_set_rx_mode_async callback that drivers can implement instead of the legacy ndo_set_rx_mode. The legacy callback runs under the netif_addr_lock spinlock with BHs disabled, preventing drivers from sleeping. The async variant runs from a work queue with rtnl_lock and netdev_lock_ops held, in fully sleepable context. When __dev_set_rx_mode() sees ndo_set_rx_mode_async, it schedules netdev_rx_mode_work instead of calling the driver inline. The work function takes two snapshots of each address list (uc/mc) under the addr_lock, then drops the lock and calls the driver with the work copies. After the driver returns, it reconciles the snapshots back to the real lists under the lock. Add netif_rx_mode_sync() to opportunistically execute the pending workqueue update inline, so that rx mode changes are committed before returning to userspace: - dev_change_flags (SIOCSIFFLAGS / RTM_NEWLINK) - dev_set_promiscuity - dev_set_allmulti - dev_ifsioc SIOCADDMULTI / SIOCDELMULTI - do_setlink (RTM_SETLINK) Note that some deep hierarchies still do skip the lower updates via: - dev_uc_sync - dev_mc_sync If we do end up hitting user-visible issues, we can add more calls to netif_rx_mode_sync in specific places. But hopefully we should not, the actual user-visible lists are still synced, it's that just HW state that might be lagging. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260416185712.2155425-3-sdf@fomichev.me Signed-off-by: Paolo Abeni

Merge tag 'nf-next-26-04-10' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next

2026-04-12T16:39:21+00:00

Florian Westphal says: ==================== netfilter: updates for net-next 1-3) IPVS updates from Julian Anastasov to enhance visibility into IPVS internal state by exposing hash size, load factor etc and allows userspace to tune the load factor used for resizing hash tables. 4) reject empty/not nul terminated device names from xt_physdev. This isn't a bug fix; existing code doesn't require a c-string. But clean this up anyway because conceptually the interface name definitely should be a c-string. 5) Switch nfnetlink to skb_mac_header helpers that didn't exist back when this code was written. This gives us additional debug checks but is not intended to change functionality. 6) Let the xt ttl/hoplimit match reject unknown operator modes. This is a cleanup, the evaluation function simply returns false when the mode is out of range. From Marino Dzalto. 7) xt_socket match should enable defrag after all other checks. This bug is harmless, historically defrag could not be disabled either except by rmmod. 8) remove UDP-Lite conntrack support, from Fernando Fernandez Mancera. 9) Avoid a couple -Wflex-array-member-not-at-end warnings in the old xtables 32bit compat code, from Gustavo A. R. Silva. 10) nftables fwd expression should drop packets when their ttl/hl has expired. This is a bug fix deferred, its not deemed important enough for -rc8. 11) Add additional checks before assuming the mac header is an ethernet header, from Zhengchuan Liang. * tag 'nf-next-26-04-10' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: require Ethernet MAC header before using eth_hdr() netfilter: nft_fwd_netdev: check ttl/hl before forwarding netfilter: x_tables: Avoid a couple -Wflex-array-member-not-at-end warnings netfilter: conntrack: remove UDP-Lite conntrack support netfilter: xt_socket: enable defrag after all other checks netfilter: xt_HL: add pr_fmt and checkentry validation netfilter: nfnetlink: prefer skb_mac_header helpers netfilter: x_physdev: reject empty or not-nul terminated device names ipvs: add conn_lfactor and svc_lfactor sysctl vars ipvs: add ip_vs_status info ipvs: show the current conn_tab size to users ==================== Link: https://patch.msgid.link/20260410112352.23599-1-fw@strlen.de Signed-off-by: Jakub Kicinski

docs: net: bridge: document stp_mode attribute

2026-04-10T22:52:25+00:00

Add documentation for the IFLA_BR_STP_MODE bridge attribute in the "User space STP helper" section of the bridge documentation. Reference the BR_STP_MODE_* values via kernel-doc and describe the use case for network namespace environments. Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Signed-off-by: Andy Roulin Link: https://patch.msgid.link/20260405205224.3163000-3-aroulin@nvidia.com Signed-off-by: Jakub Kicinski