kernel/linux.git/net/bridge, branch v6.12.107

netfilter: bridge: release template ct on non-IP path

2026-08-19T16:14:26+00:00

commit d45cc8020d7c0a9f01dee42ff5c40bc14c9af72f upstream. A bridge nftables ct zone set rule can attach a conntrack template to an skb before nf_ct_bridge_pre() sees it. For non-IPv4 and non-IPv6 EtherTypes, nf_ct_bridge_pre() currently overwrites skb->_nfct with IP_CT_UNTRACKED without releasing the existing template reference. That makes the per-cpu template, and any temporary templates allocated for concurrent use, unreachable and leaks memory until the host runs out of slab. Reset the skb conntrack state before marking the frame untracked so the existing template reference is dropped on the non-IP path. Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

net: bridge: mrp: fix uninitialised bytes on the wire

2026-08-19T16:14:20+00:00

commit 63488dba65ef91373ef616575b32eb0eb21459f4 upstream. br_mrp_alloc_test_skb() builds MRP test frames on an skb from dev_alloc_skb(), which does not clear the linear data area. On the MRA ring-role branch the sub-option TLV header is appended with sub_tlv = skb_put(skb, sizeof(*sub_tlv)); sub_tlv->type = BR_MRP_SUB_TLV_HEADER_TEST_AUTO_MGR; so sub_tlv->length is never written, and the two trailing alignment bytes are appended with a bare skb_put() that does not clear them either. The neighbouring oui and sub_opt regions are explicitly zeroed, so three uninitialised bytes are left in every MRA MRP_Test frame that goes out. Put the sub-option TLV header and the alignment padding in a single skb_put_zero(), which clears both. The AUTO_MGR sub-TLV carries no payload, so the zeroed length field is already the value it should have. Fixes: f7458934b079 ("net: bridge: mrp: Update the Test frames for MRA") Suggested-by: Nikolay Aleksandrov Cc: stable@vger.kernel.org Signed-off-by: Baul Lee Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260729131941.10254-1-baul.lee@xbow.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

netfilter: ebt_nflog: pin the NFLOG backend

2026-08-19T16:14:19+00:00

commit 30825970339c107bacaf7f61af90fcdb1f597ca1 upstream. nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the ULOG logger module reference when an ebt_nflog rule is validated and release it when the rule is destroyed. Request the NFLOG backend for legacy callers when needed, matching xt_NFLOG. This prevents module teardown until all ebt_nflog rules have stopped using the logger. Fixes: c83fa19603bd ("netfilter: nf_log: don't call synchronize_rcu in nf_log_unset") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

net: bridge: stop fast-leave after deleting a port group

2026-08-09T18:23:14+00:00

commit a39789f211b8a4125f0c70e05b30cf715f4f187d upstream. br_multicast_leave_group() iterates mp->ports with pp = &p->next in its fast-leave path. After br_multicast_del_pg() removes p, continuing the loop advances pp through the deleted entry. If multicast-to-unicast was enabled, the bridge can hold multiple port groups for the same port and group with different source MAC addresses. Once multicast-to-unicast is disabled, br_port_group_equal() matches those entries by port only. A fast leave can then delete one entry and continue from its stale next pointer, leaving mp->ports pointing at a deleted port group. Fast leave only needs to remove one matching port group. Break after br_multicast_del_pg() so the loop stops before dereferencing the removed entry. Fixes: 6db6f0eae605 ("bridge: multicast to unicast") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Signed-off-by: Ren Wei Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/1cf0898872ef7c72d5f4c0304414a192c6dac591.1784707712.git.zhilinz@nebusec.ai Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: bridge: mrp: fix Option TLV length in MRP_Test frames

2026-08-09T18:23:05+00:00

[ Upstream commit 5546da86894d5906f131b05890705a7abf949d84 ] oui is a pointer, so sizeof(oui) is the pointer size. The MRA Option TLV thus advertises a wrong length (15 vs 10 on x86_64), causing misparsing of the frame on peers. Fix is to replace with sizeof(*oui). Fixes: f7458934b079 ("net: bridge: mrp: Update the Test frames for MRA") Signed-off-by: David Corvaglia Acked-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20260726062605.2746-1-david@corvaglia.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: br_netfilter: Reallocate headroom if necessary in neigh_hh_bridge()

2026-08-09T18:23:00+00:00

[ Upstream commit b2870fc21601db9133bc70c48c603b487614fa3b ] neigh_hh_bridge() assumes the skb always has sufficient headroom to copy the aligned L2 header. This assumption can trigger the crash reported below using the following netfilter setup: $modprobe br_netfilter $sysctl -w net.bridge.bridge-nf-call-iptables=1 $root@OpenWrt:~# nft list ruleset table ip nat { chain prerouting { type nat hook prerouting priority dstnat; policy accept; ip daddr 192.168.83.123 dnat to 192.168.83.120 } } - iperf3 client (192.168.83.119) --> bridge (192.168.83.118) --> iperf3 server (192.168.83.120) the iperf3 client is sending packet for 192.168.83.123 to the bridge device. [ 1579.036575] Unable to handle kernel write to read-only memory at virtual address ffffff8004d76ffe [ 1579.045482] Mem abort info: [ 1579.048273] ESR = 0x000000009600004f [ 1579.052024] EC = 0x25: DABT (current EL), IL = 32 bits [ 1579.057363] SET = 0, FnV = 0 [ 1579.060417] EA = 0, S1PTW = 0 [ 1579.063550] FSC = 0x0f: level 3 permission fault [ 1579.068345] Data abort info: [ 1579.071224] ISV = 0, ISS = 0x0000004f, ISS2 = 0x00000000 [ 1579.076720] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 [ 1579.081770] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 1579.087092] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000080dc4000 [ 1579.093794] [ffffff8004d76ffe] pgd=180000009ffff003, p4d=180000009ffff003, pud=180000009ffff003, pmd=180000009ffe3003, pte=0060000084d76787 [ 1579.106343] Internal error: Oops: 000000009600004f [#1] SMP [ 1579.193824] CPU: 0 UID: 0 PID: 235 Comm: napi/qdma_eth-3 Tainted: G O 6.12.57 #0 [ 1579.202614] Tainted: [O]=OOT_MODULE [ 1579.206102] Hardware name: Airoha AN7581 Evaluation Board (DT) [ 1579.211929] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1579.218889] pc : br_nf_pre_routing_finish_bridge+0x1ac/0xcc8 [br_netfilter] [ 1579.225859] lr : br_nf_pre_routing_finish_bridge+0x18c/0xcc8 [br_netfilter] [ 1579.232822] sp : ffffffc0817cba20 [ 1579.236128] x29: ffffffc0817cba20 x28: 0000000000000000 x27: ffffff8002b89000 [ 1579.243273] x26: ffffff8004d7700e x25: 0000000000000008 x24: 0000000000000000 [ 1579.250416] x23: ffffffc08179d4c0 x22: 0000000000000000 x21: ffffffc08179d4c0 [ 1579.257561] x20: ffffff8004d9b800 x19: ffffff8015010000 x18: 0000000000000014 [ 1579.264704] x17: ffffffbf9e930000 x16: ffffffc0817c8000 x15: 0000000000000070 [ 1579.271848] x14: 0000000000000080 x13: 0000000000000001 x12: 0000000000000000 [ 1579.278993] x11: ffffffc0798caae0 x10: ffffff8014db6fd8 x9 : 0000000000000000 [ 1579.286136] x8 : 0000000000000003 x7 : ffffffc08171f628 x6 : 000000001a3b83d3 [ 1579.293281] x5 : 0000000000000000 x4 : 1beb76f22fee0000 x3 : ffffff8004d7700e [ 1579.300425] x2 : 0000000000000000 x1 : ffffff8004d9b8bc x0 : ffffff80026ed000 [ 1579.307570] Call trace: [ 1579.310018] br_nf_pre_routing_finish_bridge+0x1ac/0xcc8 [br_netfilter] [ 1579.316632] br_nf_hook_thresh+0xd4/0x14bc [br_netfilter] [ 1579.322032] br_nf_hook_thresh+0x250/0x14bc [br_netfilter] [ 1579.327517] br_nf_hook_thresh+0x76c/0x14bc [br_netfilter] [ 1579.333003] br_handle_frame+0x180/0x480 [ 1579.336935] __netif_receive_skb_core.constprop.0+0x540/0xf40 [ 1579.342682] __netif_receive_skb_one_core+0x28/0x50 [ 1579.347561] process_backlog+0x98/0x1e0 [ 1579.351398] __napi_poll+0x34/0x1c4 [ 1579.354887] net_rx_action+0x178/0x330 [ 1579.358638] handle_softirqs+0x108/0x2d4 [ 1579.362560] __do_softirq+0x10/0x18 [ 1579.366051] ____do_softirq+0xc/0x20 [ 1579.369627] call_on_irq_stack+0x30/0x4c [ 1579.373550] do_softirq_own_stack+0x18/0x20 [ 1579.377734] do_softirq+0x4c/0x60 [ 1579.381050] __local_bh_enable_ip+0x88/0x98 [ 1579.385234] napi_threaded_poll_loop+0x188/0x21c [ 1579.389853] napi_threaded_poll+0x70/0x80 [ 1579.393863] kthread+0xd8/0xdc [ 1579.396918] ret_from_fork+0x10/0x20 [ 1579.400499] Code: 88dffc22 3707ffc2 f9406663 f9406684 (f81f0064) [ 1579.406589] ---[ end trace 0000000000000000 ]--- [ 1579.411209] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 1579.418083] SMP: stopping secondary CPUs [ 1579.422012] Kernel Offset: disabled Fix the issue reallocating the skb headroom if necessary in neigh_hh_bridge routine. Fixes: e179e6322ac33 ("netfilter: bridge-netfilter: Fix MAC header handling with IP DNAT") Reviewed-by: Ido Schimmel Signed-off-by: Lorenzo Bianconi Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nf_tables: remove register tracking infrastructure

2026-08-03T09:17:33+00:00

[ Upstream commit 6b94d081f81dd524626f7aab2b98a9de335edb72 ] This facility was disabled in commit 9e539c5b6d9c ("netfilter: nf_tables: disable expression reduction infra"), because not all nft_exprs guarantee they will update the destination register: some may set NFT_BREAK instead to cancel evaluation of the rule. This has been dead code ever since. There are no plans to salvage this at this time, so remove this. Signed-off-by: Florian Westphal Link: https://patch.msgid.link/20260224205048.4718-10-fw@strlen.de Signed-off-by: Jakub Kicinski Stable-dep-of: d07955dd34ec ("netfilter: nft_fib: reject fib expression on the netdev egress hook") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: bridge: vlan: fix vlan range dumps starting with pvid

2026-08-03T09:17:13+00:00

[ Upstream commit 43171c97e4714bf601b468401b37732244639c21 ] There is a bug in all range dumps that rely on br_vlan_can_enter_range() when the PVID is a range starting VLAN, all following VLANs that match its flags can enter the range, but when the range is filled in only the PVID VLAN is dumped and the rest of the range is discarded because br_vlan_fill_vids() checks for the PVID flag. Since the PVID VLAN can be only one, we need to break ranges around it, the best way to do that consistently for all is to alter br_vlan_can_enter_range() to take into account the PVID and return false to break the range when it's matched. Before the fix: $ ip l add br0 type bridge vlan_filtering 1 $ ip l add dumdum type dummy $ ip l set dumdum master br0 $ ip l set br0 up $ ip l set dumdum up $ bridge vlan add dev dumdum vid 1 pvid untagged master $ bridge vlan add dev dumdum vid 2 untagged master $ bridge vlan show dev dumdum # use legacy dump to show all vlans port vlan-id dumdum 1 PVID Egress Untagged 2 Egress Untagged $ bridge -d vlan show dev dumdum # use the new dump (RTM_GETVLAN) port vlan-id dumdum 1 PVID Egress Untagged state forwarding mcast_router 1 VLAN 2 is missing, and if there are more matching VLANs afterwards they'd be missing too. After the fix: [ same setup steps ] $ bridge vlan show dev dumdum port vlan-id dumdum 1 PVID Egress Untagged 2 Egress Untagged $ bridge -d vlan show dev dumdum # use the new dump (RTM_GETVLAN) port vlan-id dumdum 1 PVID Egress Untagged state forwarding mcast_router 1 2 Egress Untagged state forwarding mcast_router 1 Fixes: 0ab558795184 ("net: bridge: vlan: add rtm range support") Signed-off-by: Nikolay Aleksandrov Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260721140922.682265-2-razor@blackwall.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: ebtables: zero chainstack array

2026-07-24T14:11:49+00:00

[ Upstream commit cbfe53599eebffd188938ab6774cc41794f6f9d5 ] sashiko reports: looking at ebtables table translation, could a sparse cpu_possible_mask lead to an uninitialized pointer free? If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible, but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at CPU 2, the cleanup loop will blindly decrement and call vfree() on newinfo->chainstack[1]. Not a real-world bug, such allocation isn't expected to fail in the first place. Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

netfilter: ebtables: Use vmalloc_array() to improve code

2026-07-24T14:11:49+00:00

[ Upstream commit 46015e6b3ea75297b28d4806564f3f692cf11861 ] Remove array_size() calls and replace vmalloc() with vmalloc_array() to simplify the code. vmalloc_array() is also optimized better, uses fewer instructions, and handles overflow more concisely[1]. [1]: https://lore.kernel.org/lkml/abc66ec5-85a4-47e1-9759-2f60ab111971@vivo.com/ Signed-off-by: Qianfeng Rong Signed-off-by: Florian Westphal Stable-dep-of: cbfe53599eeb ("netfilter: ebtables: zero chainstack array") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman