kernel/linux.git/net/bridge, branch v6.6.148

netfilter: nf_tables: remove register tracking infrastructure

2026-08-03T09:15:37+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

2026-08-03T09:15:21+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

2026-07-24T14:03:49+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

2026-07-24T14:03:49+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

bridge: stp: Fix a potential use-after-free when deleting a bridge

2026-07-24T14:03:25+00:00

[ Upstream commit 2a00517db8de4be7df3d483b215c5544fb30a191 ] The three STP timers are not supposed to be armed while the bridge is administratively down. They are synchronously deactivated when the bridge is put administratively down and the various call sites check for 'IFF_UP' before arming them. This check is missing from br_topology_change_detection() and it is possible to engineer a situation in which the topology change timer is armed while the bridge is administratively down, resulting in a use-after-free [1] when the bridge is deleted. Fix by adding the missing check and for good measures synchronously shutdown the three timers when the bridge is deleted. [1] ODEBUG: free active (active state 0) object: ffff88811662b9b0 object type: timer_list hint: br_topology_change_timer_expired (net/bridge/br_stp_timer.c:120) WARNING: lib/debugobjects.c:629 at debug_print_object+0x1bc/0x450, CPU#9: ip/359 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Noam Rathaus Reported-by: Neil Young Acked-by: Nikolay Aleksandrov Signed-off-by: Ido Schimmel Reviewed-by: Breno Leitao Link: https://patch.msgid.link/20260629072117.497959-1-idosch@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

netfilter: nft_meta_bridge: fix NFT_META_BRI_IIFPVID stack leak

2026-07-24T14:03:20+00:00

[ Upstream commit 27dd2997746d54ebc079bb13161cc1bdd401d4a6 ] This needs to test for nonzero retval. Fixes: c54c7c685494 ("netfilter: nft_meta_bridge: add NFT_META_BRI_IIFPVID support") Closes: https://sashiko.dev/#/patchset/20260618061631.21919-1-fw%40strlen.de Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

bridge: cfm: reject invalid CCM interval at configuration time

2026-07-24T14:03:11+00:00

[ Upstream commit f3e02edd8322b31b8e6517faa6ba053bf29d1e26 ] ccm_tx_work_expired() re-arms itself via queue_delayed_work() using the configured exp_interval converted by interval_to_us(). When exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range, interval_to_us() returns 0, causing the worker to fire immediately in a tight loop that allocates skbs until OOM. Fix this by validating exp_interval at configuration time: - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the netlink policy so userspace cannot set an invalid value. - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has not yet been configured (defaults to 0 from kzalloc). Fixes: 2be665c3940d ("bridge: cfm: Netlink SET configuration Interface.") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Acked-by: Nikolay Aleksandrov Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260609065116.2818837-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: ebtables: terminate table name before find_table_lock()

2026-07-24T14:02:45+00:00

commit a622d2e9608c9dff47fc2e5759ac7aa3a836b45d upstream. update_counters() and compat_update_counters() forward a user-supplied 32-byte table name to find_table_lock() without NUL-terminating it. On a lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s", "ebtable_", name), and vsnprintf() reads past the name field and the stack object until it hits a zero byte. BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730) Read of size 1 at addr ffff8880119dfb20 by task exploit/147 Call Trace: ... string (lib/vsprintf.c:648 lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) __request_module (kernel/module/kmod.c:150) do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380) update_counters (net/bridge/netfilter/ebtables.c:1440) do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573) nf_setsockopt (net/netfilter/nf_sockopt.c:101) ip_setsockopt (net/ipv4/ip_sockglue.c:1424) raw_setsockopt (net/ipv4/raw.c:847) __sys_setsockopt (net/socket.c:2393) ... compat_do_replace() shares the same unterminated name via compat_copy_ebt_replace_from_user(); terminate it there too so all find_table_lock() callers behave alike. The other callers already terminate the name after the copy. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support") Cc: stable@vger.kernel.org Reported-by: Weiming Shi Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman

netfilter: ebtables: module names must be null-terminated

2026-07-24T14:02:45+00:00

commit 084d23f818321390509e9738a0b08bbf46df6425 upstream. We need to explicitly check the length, else we may pass non-null terminated string to request_module(). Cc: stable@vger.kernel.org Fixes: bcf493428840 ("netfilter: ebtables: Fix extension lookup with identical name") Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman

netfilter: bridge: make ebt_snat ARP rewrite writable

2026-06-19T11:39:26+00:00

[ Upstream commit 67ba971ae02514d85818fe0c32549ab4bfa3bf49 ] The ebtables SNAT target keeps the Ethernet source address rewrite behind skb_ensure_writable(skb, 0). This is intentional: at the bridge ebtables hooks the Ethernet header is addressed through skb_mac_header()/eth_hdr(), while skb->data points at the Ethernet payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check the payload, not the Ethernet header, and would reintroduce the small packet regression fixed by commit 63137bc5882a. However, the optional ARP sender hardware address rewrite is different. It writes through skb_store_bits() at an offset relative to skb->data: skb_store_bits(skb, sizeof(struct arphdr), info->mac, ETH_ALEN) skb_header_pointer() only safely reads the ARP header; it does not make the later sender hardware address range writable. If that range is still held in a nonlinear skb fragment backed by a splice-imported file page, skb_store_bits() maps the frag page and copies the new MAC address directly into it. Ensure the ARP SHA range is writable before reading the ARP header and before calling skb_store_bits(). Fixes: 63137bc5882a ("netfilter: ebtables: Fixes dropping of small packets in bridge nat") Reported-by: Yiming Qian Signed-off-by: Yiming Qian Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin