kernel/linux.git/net/core, branch master

page_pool: fix memory-provider leak in page_pool_create_percpu() error path

2026-04-30T02:11:49+00:00

When page_pool_create_percpu() fails on page_pool_list(), it falls through to its err_uninit: label, which calls page_pool_uninit(). At that point page_pool_init() has already taken two references when the user requested PP_FLAG_ALLOW_UNREADABLE_NETMEM: pool->mp_ops->init(pool) static_branch_inc(&page_pool_mem_providers); Neither is undone by page_pool_uninit(); both are only undone by __page_pool_destroy() (success-side teardown). The error path therefore leaks the per-provider reference taken by mp_ops->init (io_zcrx_ifq->refs in the io_uring zcrx provider, the dmabuf binding refcount in the devmem provider) plus one increment of the page_pool_mem_providers static branch on every failure of xa_alloc_cyclic() inside page_pool_list(). The leaked io_zcrx_ifq->refs in turn pins everything io_zcrx_ifq_free() would release on cleanup: ifq->user (uid), ifq->mm_account (mmdrop), ifq->dev (device refcount), ifq->netdev_tracker (netdev refcount), and the rbuf region. The leaked static branch increment forces all subsequent page_pool_alloc_netmems() and page_pool_return_page() callers to take the slow mp_ops branch for the lifetime of the kernel. Reachable via the io_uring zcrx path: io_uring_register(IORING_REGISTER_ZCRX_IFQ) /* CAP_NET_ADMIN */ -> __io_uring_register -> io_register_zcrx -> zcrx_register_netdev -> netif_mp_open_rxq -> driver ndo_queue_mem_alloc -> page_pool_create_percpu -> page_pool_init succeeds (mp_ops->init runs, branch++) -> page_pool_list fails (xa_alloc_cyclic -ENOMEM) -> goto err_uninit <-- leak The same shape applies to the devmem dmabuf provider via mp_dmabuf_devmem_init()/mp_dmabuf_devmem_destroy(). Restore the cleanup symmetry by moving the mp_ops->destroy() and static_branch_dec() calls out of __page_pool_destroy() and into page_pool_uninit(), so page_pool_uninit() is again the strict inverse of page_pool_init(). page_pool_uninit() has only two callers (the err_uninit: path and __page_pool_destroy()), so this preserves the single-call invariant on the success path while fixing the err path. The error path of page_pool_init() itself still skips the mp_ops cleanup correctly: mp_ops->init is the last action that takes a reference before page_pool_init() returns 0, so when it returns an error neither the refcount nor the static branch has been touched. Triggering the bug requires xa_alloc_cyclic() to fail with -ENOMEM, which under normal GFP_KERNEL retry behaviour is rare. It is deterministic under CONFIG_FAULT_INJECTION with fail_page_alloc / xa fault injection, or under sustained memory pressure. The leak is silent: there is no warning, and the released kernel build continues running with a permanently-incremented static branch. Fixes: 0f9214046893 ("memory-provider: dmabuf devmem memory provider") Signed-off-by: Hasan Basbunar Link: https://patch.msgid.link/20260428170739.34881-1-basbunarhasan@gmail.com Signed-off-by: Jakub Kicinski

net: add net_iov_init() and use it to initialize ->page_type

2026-04-29T23:40:08+00:00

Commit db359fccf212 ("mm: introduce a new page type for page pool in page type") added a page_type field to struct net_iov at the same offset as struct page::page_type, so that page_pool_set_pp_info() can call __SetPageNetpp() uniformly on both pages and net_iovs. The page-type API requires the field to hold the UINT_MAX "no type" sentinel before a type can be set; for real struct page that invariant is established by the page allocator on free. struct net_iov is not allocated through the page allocator, so the field is left as zero (io_uring zcrx, which uses __GFP_ZERO) or as slab garbage (devmem, which uses kvmalloc_objs() without zeroing). When the page pool then calls page_pool_set_pp_info() on a freshly-bound niov, __SetPageNetpp()'s VM_BUG_ON_PAGE(page->page_type != UINT_MAX) fires and the kernel BUGs. Triggered in selftests by io_uring zcrx setup through the fbnic queue restart path: kernel BUG at ./include/linux/page-flags.h:1062! RIP: 0010:page_pool_set_pp_info (./include/linux/page-flags.h:1062 net/core/page_pool.c:716) Call Trace: net_mp_niov_set_page_pool (net/core/page_pool.c:1360) io_pp_zc_alloc_netmems (io_uring/zcrx.c:1089 io_uring/zcrx.c:1110) fbnic_fill_bdq (./include/net/page_pool/helpers.h:160 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:906) __fbnic_nv_restart (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2470 drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2874) fbnic_queue_start (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2903) netdev_rx_queue_reconfig (net/core/netdev_rx_queue.c:137) __netif_mp_open_rxq (net/core/netdev_rx_queue.c:234) io_register_zcrx (io_uring/zcrx.c:818 io_uring/zcrx.c:903) __io_uring_register (io_uring/register.c:931) __do_sys_io_uring_register (io_uring/register.c:1029) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) The same path is reachable through devmem dmabuf binding via netdev_nl_bind_rx_doit() -> net_devmem_bind_dmabuf_to_queue(). Add a net_iov_init() helper that stamps ->owner, ->type and the ->page_type sentinel, and use it from both the devmem and io_uring zcrx niov init loops. Fixes: db359fccf212 ("mm: introduce a new page type for page pool in page type") Acked-by: Vlastimil Babka (SUSE) Acked-by: Byungchul Park Reviewed-by: Jens Axboe Acked-by: Pavel Begunkov Link: https://patch.msgid.link/20260428025320.853452-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

netpoll: fix IPv6 local-address corruption

2026-04-28T02:16:18+00:00

netpoll_setup() decides whether to auto-populate the local source address by testing np->local_ip.ip, which only inspects the first 4 bytes of the union inet_addr storage. For an IPv6 netpoll whose caller-supplied local address has a zero high-32 bits (::1, ::, IPv4-mapped ::ffff:a.b.c.d, etc.), this misdetects the address as unset (which they are not, but the first 4 bytes are empty), calls netpoll_take_ipv6() and overwrites it with whatever matching link-local/global address the device happens to expose first. Introduce a helper netpoll_local_ip_unset() that picks the correct family-aware test (ipv6_addr_any() for IPv6, !.ip for IPv4) and use it from netpoll_setup(). Reproducer is something like: echo "::2" > local_ip echo 1 > enabled cat local_ip # before this fix: 2001:db8::1 (caller-supplied ::2 was clobbered) # after this fix: ::2 Fixes: b7394d2429c1 ("netpoll: prepare for ipv6") Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20260424-netpoll_fix-v1-1-3a55348c625f@debian.org Signed-off-by: Jakub Kicinski

neigh: let neigh_xmit take skb ownership

2026-04-28T02:02:11+00:00

neigh_xmit always releases the skb, except when no neighbour table is found. But even the first added user of neigh_xmit (mpls) relied on neigh_xmit to release the skb (or queue it for tx). sashiko reported: If neigh_xmit() is called with an uninitialized neighbor table (for example, NEIGH_ND_TABLE when IPv6 is disabled), it returns -EAFNOSUPPORT and bypasses its internal out_kfree_skb error path. Because the return value of neigh_xmit() is ignored here, does this leak the SKB? Assume full ownership and remove the last code path that doesn't xmit or free skb. Fixes: 4fd3d7d9e868 ("neigh: Add helper function neigh_xmit") Signed-off-by: Florian Westphal Reviewed-by: Kuniyuki Iwashima Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260424145843.74055-1-fw@strlen.de Signed-off-by: Jakub Kicinski

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

Merge tag 'net-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-04-23T23:50:42+00:00

Pull networking fixes from Jakub Kicinski: "Including fixes from Netfilter. Steady stream of fixes. Last two weeks feel comparable to the two weeks before the merge window. Lots of AI-aided bug discovery. A newer big source is Sashiko/Gemini (Roman Gushchin's system), which points out issues in existing code during patch review (maybe 25% of fixes here likely originating from Sashiko). Nice thing is these are often fixed by the respective maintainers, not drive-bys. Current release - new code bugs: - kconfig: MDIO_PIC64HPSC should depend on ARCH_MICROCHIP Previous releases - regressions: - add async ndo_set_rx_mode and switch drivers which we promised to be called under the per-netdev mutex to it - dsa: remove duplicate netdev_lock_ops() for conduit ethtool ops - hv_sock: report EOF instead of -EIO for FIN - vsock/virtio: fix MSG_PEEK calculation on bytes to copy Previous releases - always broken: - ipv6: fix possible UAF in icmpv6_rcv() - icmp: validate reply type before using icmp_pointers - af_unix: drop all SCM attributes for SOCKMAP - netfilter: fix a number of bugs in the osf (OS fingerprinting) - eth: intel: fix timestamp interrupt configuration for E825C Misc: - bunch of data-race annotations" * tag 'net-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (148 commits) rxrpc: Fix error handling in rxgk_extract_token() rxrpc: Fix re-decryption of RESPONSE packets rxrpc: Fix rxrpc_input_call_event() to only unshare DATA packets rxrpc: Fix missing validation of ticket length in non-XDR key preparsing rxgk: Fix potential integer overflow in length check rxrpc: Fix conn-level packet handling to unshare RESPONSE packets rxrpc: Fix potential UAF after skb_unshare() failure rxrpc: Fix rxkad crypto unalignment handling rxrpc: Fix memory leaks in rxkad_verify_response() net: rds: fix MR cleanup on copy error m68k: mvme147: Make me the maintainer net: txgbe: fix firmware version check selftests/bpf: check epoll readiness during reuseport migration tcp: call sk_data_ready() after listener migration vhost_net: fix sleeping with preempt-disabled in vhost_net_busy_poll() ipv6: Cap TLV scan in ip6_tnl_parse_tlv_enc_lim tipc: fix double-free in tipc_buf_append() llc: Return -EINPROGRESS from llc_ui_connect() ipv4: icmp: validate reply type before using icmp_pointers selftests/net: packetdrill: cover RFC 5961 5.2 challenge ACK on both edges ...

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: warn ops-locked drivers still using ndo_set_rx_mode

2026-04-21T10:50:25+00:00

Now that all in-tree ops-locked drivers have been converted to ndo_set_rx_mode_async, add a warning in register_netdevice to catch any remaining or newly added drivers that use ndo_set_rx_mode with ops locking. This ensures future driver authors are guided toward the async path. Also route ops-locked devices through netdev_rx_mode_work even if they lack rx_mode NDOs, to ensure netdev_ops_assert_locked() does not fire on the legacy path where only RTNL is held. Reviewed-by: Aleksandr Loktionov Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260416185712.2155425-14-sdf@fomichev.me Signed-off-by: Paolo Abeni

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: cache snapshot entries for ndo_set_rx_mode_async

2026-04-21T10:50:13+00:00

Add a per-device netdev_hw_addr_list cache (rx_mode_addr_cache) that allows __hw_addr_list_snapshot() and __hw_addr_list_reconcile() to reuse previously allocated entries instead of hitting GFP_ATOMIC on every snapshot cycle. snapshot pops entries from the cache when available, falling back to __hw_addr_create(). reconcile splices both snapshot lists back into the cache via __hw_addr_splice(). The cache is flushed in free_netdev(). Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260416185712.2155425-4-sdf@fomichev.me Signed-off-by: Paolo Abeni