kernel/net/bridge, branch master

bridge: cfm: Fix race condition in peer_mep deletion

2026-03-13T01:33:52Z

When a peer MEP is being deleted, cancel_delayed_work_sync() is called on ccm_rx_dwork before freeing. However, br_cfm_frame_rx() runs in softirq context under rcu_read_lock (without RTNL) and can re-schedule ccm_rx_dwork via ccm_rx_timer_start() between cancel_delayed_work_sync() returning and kfree_rcu() being called. The following is a simple race scenario: cpu0 cpu1 mep_delete_implementation() cancel_delayed_work_sync(ccm_rx_dwork); br_cfm_frame_rx() // peer_mep still in hlist if (peer_mep->ccm_defect) ccm_rx_timer_start() queue_delayed_work(ccm_rx_dwork) hlist_del_rcu(&peer_mep->head); kfree_rcu(peer_mep, rcu); ccm_rx_work_expired() // on freed peer_mep To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync() in both peer MEP deletion paths, so that subsequent queue_delayed_work() calls from br_cfm_frame_rx() are silently rejected. The cc_peer_disable() helper retains cancel_delayed_work_sync() because it is also used for the CC enable/disable toggle path where the work must remain re-schedulable. Fixes: dc32cbb3dbd7 ("bridge: cfm: Kernel space implementation of CFM. CCM frame RX added.") Signed-off-by: Hyunwoo Kim Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/abBgYT5K_FI9rD1a@v4bel Signed-off-by: Jakub Kicinski

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled

2026-03-05T15:52:56Z

When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled. Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports") Reported-by: Guruprasad C P Closes: https://lore.kernel.org/netdev/CAHXs0ORzd62QOG-Fttqa2Cx_A_VFp=utE2H2VTX5nqfgs7LDxQ@mail.gmail.com/ Signed-off-by: Fernando Fernandez Mancera Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260304120357.9778-1-fmancera@suse.de Signed-off-by: Jakub Kicinski

bridge: Check relevant per-VLAN options in VLAN range grouping

2026-02-27T03:24:29Z

The br_vlan_opts_eq_range() function determines if consecutive VLANs can be grouped together in a range for compact netlink notifications. It currently checks state, tunnel info, and multicast router configuration, but misses two categories of per-VLAN options that affect the output: 1. User-visible priv_flags (neigh_suppress, mcast_enabled) 2. Port multicast context (mcast_max_groups, mcast_n_groups) When VLANs have different settings for these options, they are incorrectly grouped into ranges, causing netlink notifications to report only one VLAN's settings for the entire range. Fix by checking priv_flags equality, but only for flags that affect netlink output (BR_VLFLAG_NEIGH_SUPPRESS_ENABLED and BR_VLFLAG_MCAST_ENABLED), and comparing multicast context (mcast_max_groups and mcast_n_groups). Example showing the bugs before the fix: $ bridge vlan set vid 10 dev dummy1 neigh_suppress on $ bridge vlan set vid 11 dev dummy1 neigh_suppress off $ bridge -d vlan show dev dummy1 port vlan-id dummy1 10-11 ... neigh_suppress on $ bridge vlan set vid 10 dev dummy1 mcast_max_groups 100 $ bridge vlan set vid 11 dev dummy1 mcast_max_groups 200 $ bridge -d vlan show dev dummy1 port vlan-id dummy1 10-11 ... mcast_max_groups 100 After the fix, VLANs 10 and 11 are shown as separate entries with their correct individual settings. Fixes: a1aee20d5db2 ("net: bridge: Add netlink knobs for number / maximum MDB entries") Fixes: 83f6d600796c ("bridge: vlan: Allow setting VLAN neighbor suppression state") Signed-off-by: Danielle Ratson Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260225143956.3995415-2-danieller@nvidia.com Signed-off-by: Jakub Kicinski

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33Z

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

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

2026-02-22T01:09:51Z

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

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28Z

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

Merge tag 'net-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-02-19T18:39:08Z

Pull networking fixes from Jakub Kicinski: "Including fixes from Netfilter. Current release - new code bugs: - net: fix backlog_unlock_irq_restore() vs CONFIG_PREEMPT_RT - eth: mlx5e: XSK, Fix unintended ICOSQ change - phy_port: correctly recompute the port's linkmodes - vsock: prevent child netns mode switch from local to global - couple of kconfig fixes for new symbols Previous releases - regressions: - nfc: nci: fix false-positive parameter validation for packet data - net: do not delay zero-copy skbs in skb_attempt_defer_free() Previous releases - always broken: - mctp: ensure our nlmsg responses to user space are zero-initialised - ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data() - fixes for ICMP rate limiting Misc: - intel: fix PCI device ID conflict between i40e and ipw2200" * tag 'net-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (85 commits) net: nfc: nci: Fix parameter validation for packet data net/mlx5e: Use unsigned for mlx5e_get_max_num_channels net/mlx5e: Fix deadlocks between devlink and netdev instance locks net/mlx5e: MACsec, add ASO poll loop in macsec_aso_set_arm_event net/mlx5: Fix misidentification of write combining CQE during poll loop net/mlx5e: Fix misidentification of ASO CQE during poll loop net/mlx5: Fix multiport device check over light SFs bonding: alb: fix UAF in rlb_arp_recv during bond up/down bnge: fix reserving resources from FW eth: fbnic: Advertise supported XDP features. rds: tcp: fix uninit-value in __inet_bind net/rds: Fix NULL pointer dereference in rds_tcp_accept_one octeontx2-af: Fix default entries mcam entry action net/mlx5e: XSK, Fix unintended ICOSQ change ipv6: icmp: icmpv6_xrlim_allow() optimization if net.ipv6.icmp.ratelimit is zero ipv4: icmp: icmpv4_xrlim_allow() optimization if net.ipv4.icmp_ratelimit is zero ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() inet: move icmp_global_{credit,stamp} to a separate cache line icmp: prevent possible overflow in icmp_global_allow() selftests/net: packetdrill: add ipv4-mapped-ipv6 tests ...

net: bridge: mcast: always update mdb_n_entries for vlan contexts

2026-02-17T12:00:14Z

syzbot triggered a warning[1] about the number of mdb entries in a context. It turned out that there are multiple ways to trigger that warning today (some got added during the years), the root cause of the problem is that the increase is done conditionally, and over the years these different conditions increased so there were new ways to trigger the warning, that is to do a decrease which wasn't paired with a previous increase. For example one way to trigger it is with flush: $ ip l add br0 up type bridge vlan_filtering 1 mcast_snooping 1 $ ip l add dumdum up master br0 type dummy $ bridge mdb add dev br0 port dumdum grp 239.0.0.1 permanent vid 1 $ ip link set dev br0 down $ ip link set dev br0 type bridge mcast_vlan_snooping 1 ^^^^ this will enable snooping, but will not update mdb_n_entries because in __br_multicast_enable_port_ctx() we check !netif_running $ bridge mdb flush dev br0 ^^^ this will trigger the warning because it will delete the pg which we added above, which will try to decrease mdb_n_entries Fix the problem by removing the conditional increase and always keep the count up-to-date while the vlan exists. In order to do that we have to first initialize it on port-vlan context creation, and then always increase or decrease the value regardless of mcast options. To keep the current behaviour we have to enforce the mdb limit only if the context is port's or if the port-vlan's mcast snooping is enabled. [1] ------------[ cut here ]------------ n == 0 WARNING: net/bridge/br_multicast.c:718 at br_multicast_port_ngroups_dec_one net/bridge/br_multicast.c:718 [inline], CPU#0: syz.4.4607/22043 WARNING: net/bridge/br_multicast.c:718 at br_multicast_port_ngroups_dec net/bridge/br_multicast.c:771 [inline], CPU#0: syz.4.4607/22043 WARNING: net/bridge/br_multicast.c:718 at br_multicast_del_pg+0x1bbe/0x1e20 net/bridge/br_multicast.c:825, CPU#0: syz.4.4607/22043 Modules linked in: CPU: 0 UID: 0 PID: 22043 Comm: syz.4.4607 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:br_multicast_port_ngroups_dec_one net/bridge/br_multicast.c:718 [inline] RIP: 0010:br_multicast_port_ngroups_dec net/bridge/br_multicast.c:771 [inline] RIP: 0010:br_multicast_del_pg+0x1bbe/0x1e20 net/bridge/br_multicast.c:825 Code: 41 5f 5d e9 04 7a 48 f7 e8 3f 73 5c f7 90 0f 0b 90 e9 cf fd ff ff e8 31 73 5c f7 90 0f 0b 90 e9 16 fd ff ff e8 23 73 5c f7 90 <0f> 0b 90 e9 60 fd ff ff e8 15 73 5c f7 eb 05 e8 0e 73 5c f7 48 8b RSP: 0018:ffffc9000c207220 EFLAGS: 00010293 RAX: ffffffff8a68042d RBX: ffff88807c6f1800 RCX: ffff888066e90000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff888066e90000 R09: 000000000000000c R10: 000000000000000c R11: 0000000000000000 R12: ffff8880303ef800 R13: dffffc0000000000 R14: ffff888050eb11c4 R15: 1ffff1100a1d6238 FS: 00007fa45921b6c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa4591f9ff8 CR3: 0000000081df2000 CR4: 00000000003526f0 Call Trace: br_mdb_flush_pgs net/bridge/br_mdb.c:1525 [inline] br_mdb_flush net/bridge/br_mdb.c:1544 [inline] br_mdb_del_bulk+0x5e2/0xb20 net/bridge/br_mdb.c:1561 rtnl_mdb_del+0x48a/0x640 net/core/rtnetlink.c:-1 rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:6967 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa45839aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa45921b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa458615fa0 RCX: 00007fa45839aeb9 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007fa458408c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa458616038 R14: 00007fa458615fa0 R15: 00007fff0b59fae8 Fixes: b57e8d870d52 ("net: bridge: Maintain number of MDB entries in net_bridge_mcast_port") Reported-by: syzbot+d5d1b7343531d17bd3c5@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/aYrWbRp83MQR1ife@debil/T/#t Reviewed-by: Ido Schimmel Signed-off-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260213070031.1400003-2-nikolay@nvidia.com Signed-off-by: Paolo Abeni

Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-12T20:13:01Z

Pull non-MM updates from Andrew Morton: - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves disk space by teaching ocfs2 to reclaim suballocator block group space (Heming Zhao) - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the ARRAY_END() macro and uses it in various places (Alejandro Colomar) - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the page size (Pnina Feder) - "kallsyms: Prevent invalid access when showing module buildid" cleans up kallsyms code related to module buildid and fixes an invalid access crash when printing backtraces (Petr Mladek) - "Address page fault in ima_restore_measurement_list()" fixes a kexec-related crash that can occur when booting the second-stage kernel on x86 (Harshit Mogalapalli) - "kho: ABI headers and Documentation updates" updates the kexec handover ABI documentation (Mike Rapoport) - "Align atomic storage" adds the __aligned attribute to atomic_t and atomic64_t definitions to get natural alignment of both types on csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain) - "kho: clean up page initialization logic" simplifies the page initialization logic in kho_restore_page() (Pratyush Yadav) - "Unload linux/kernel.h" moves several things out of kernel.h and into more appropriate places (Yury Norov) - "don't abuse task_struct.group_leader" removes the usage of ->group_leader when it is "obviously unnecessary" (Oleg Nesterov) - "list private v2 & luo flb" adds some infrastructure improvements to the live update orchestrator (Pasha Tatashin) * tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits) watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency procfs: fix missing RCU protection when reading real_parent in do_task_stat() watchdog/softlockup: fix sample ring index wrap in need_counting_irqs() kcsan, compiler_types: avoid duplicate type issues in BPF Type Format kho: fix doc for kho_restore_pages() tests/liveupdate: add in-kernel liveupdate test liveupdate: luo_flb: introduce File-Lifecycle-Bound global state liveupdate: luo_file: Use private list list: add kunit test for private list primitives list: add primitives for private list manipulations delayacct: fix uapi timespec64 definition panic: add panic_force_cpu= parameter to redirect panic to a specific CPU netclassid: use thread_group_leader(p) in update_classid_task() RDMA/umem: don't abuse current->group_leader drm/pan*: don't abuse current->group_leader drm/amd: kill the outdated "Only the pthreads threading model is supported" checks drm/amdgpu: don't abuse current->group_leader android/binder: use same_thread_group(proc->tsk, current) in binder_mmap() android/binder: don't abuse current->group_leader kho: skip memoryless NUMA nodes when reserving scratch areas ...

net/ipv6: Introduce payload_len helpers

2026-02-07T04:50:03Z

The next commits will transition away from using the hop-by-hop extension header to encode packet length for BIG TCP. Add wrappers around ip6->payload_len that return the actual value if it's non-zero, and calculate it from skb->len if payload_len is set to zero (and a symmetrical setter). The new helpers are used wherever the surrounding code supports the hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h). No behavioral change in this commit. Signed-off-by: Alice Mikityanska Acked-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260205133925.526371-2-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski