kernel/linux.git/net/netfilter, branch v5.10.259

netfilter: nft_fib: fix stale stack leak via the OIFNAME register

2026-06-19T11:21:47+00:00

[ Upstream commit ab185e0c4fb82dfba6fb86f8271e06f931d9c64c ] For NFT_FIB_RESULT_OIFNAME the destination register is declared with len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail, RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one register via "*dest = 0". The remaining three registers are left as whatever was on the stack in nft_do_chain()'s struct nft_regs, and a downstream expression that loads the register span can leak that uninitialised kernel stack to userspace. The NFTA_FIB_F_PRESENT existence check has the same shape: it is only meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type while the eval stores a single byte via nft_reg_store8(), leaving the rest of the declared span stale. Fix both: - replace the bare "*dest = 0" in the eval with nft_fib_store_result(), which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already used on the other early-return path), and - restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its destination as a single u8, so the marked span matches the one byte the eval writes. Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression") Suggested-by: Florian Westphal Cc: stable@vger.kernel.org Signed-off-by: Davide Ornaghi Signed-off-by: Pablo Neira Ayuso [ kept the tree's existing `ip6_route_lookup`/`rt6_info` machinery (missing `fib6_lookup` refactor) and changed only `*dest = 0;` to `nft_fib_store_result(dest, priv, NULL)` ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

use less confusing names for iov_iter direction initializers

2026-06-19T11:21:45+00:00

[ Upstream commit de4eda9de2d957ef2d6a8365a01e26a435e958cb ] READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro Stable-dep-of: a4f0b001782b ("vsock/virtio: reset connection on receiving queue overflow") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

netfilter: nf_queue: hold bridge skb->dev while queued

2026-06-19T11:21:45+00:00

[ Upstream commit e196115ec330a18de415bdb9f5071aa9f08e53ce ] br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection. When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free. Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling. Fixes: ac2863445686 ("netfilter: bridge: add nf_afinfo to enable queuing to userspace") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Haoze Xie Signed-off-by: Ren Wei Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: Remove redundant if statements

2026-06-19T11:21:45+00:00

[ Upstream commit 1160dfa178eb848327e9dec39960a735f4dc1685 ] The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Yajun Deng Signed-off-by: David S. Miller Stable-dep-of: e196115ec330 ("netfilter: nf_queue: hold bridge skb->dev while queued") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipvs: skip ipv6 extension headers for csum checks

2026-06-19T11:21:40+00:00

commit 05cfe9863ef049d98141dc2969eefde72fb07625 upstream. Protocol checksum validation fails for IPv6 if there are extension headers before the protocol header. iph->len already contains its offset, so use it to fix the problem. Fixes: 2906f66a5682 ("ipvs: SCTP Trasport Loadbalancing Support") Fixes: 0bbdd42b7efa ("IPVS: Extend protocol DNAT/SNAT and state handlers") Signed-off-by: Julian Anastasov Signed-off-by: Florian Westphal Signed-off-by: Nazar Kalashnikov Signed-off-by: Greg Kroah-Hartman

netfilter: nft_tunnel: fix use-after-free on object destroy

2026-06-19T11:21:37+00:00

commit c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a upstream. nft_tunnel_obj_destroy() calls metadata_dst_free() which directly kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets that took a reference via dst_hold() in nft_tunnel_obj_eval() and are still queued (e.g. in a netem qdisc) are left with a dangling pointer. When these packets are eventually dequeued, dst_release() operates on freed memory. Replace metadata_dst_free() with dst_release() so the metadata_dst is freed only after all references are dropped. The dst subsystem already handles metadata_dst cleanup in dst_destroy() when DST_METADATA is set. Fixes: af308b94a2a4 ("netfilter: nf_tables: add tunnel support") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nft_exthdr: fix register tracking for F_PRESENT flag

2026-06-19T11:21:37+00:00

[ Upstream commit 772cecf198da732faebb5dcfc46d66a505be8495 ] nft_exthdr_init() passes user-controlled priv->len to nft_parse_register_store(), which marks that many bytes in the register bitmap as initialized. However, when NFT_EXTHDR_F_PRESENT is set, the eval paths write only 1 byte (nft_reg_store8) or 4 bytes (*dest = 0 on TCP/DCCP error path). When len > 4, registers beyond the first are never written, retaining uninitialized stack data from nft_regs. Bail out if userspace requests too much data when F_PRESENT is set. Reported-by: Ji'an Zhou Fixes: c078ca3b0c5b ("netfilter: nft_exthdr: Add support for existence check") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: conntrack_irc: fix possible out-of-bounds read

2026-06-19T11:21:34+00:00

[ Upstream commit 66eba0ffce3b7e11449946b4cbbef8ea36112f56 ] When parsing fails after we've matched the command string we should bail out instead of trying to match a different command. This helper should be deprecated, given prevalence of TLS I doubt it has any relevance in 2026. Fixes: 869f37d8e48f ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port") Closes: https://sashiko.dev/#/patchset/20260525182924.28456-1-fw%40strlen.de Signed-off-by: Florian Westphal Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: synproxy: add mutex to guard hook reference counting

2026-06-19T11:21:34+00:00

[ Upstream commit 2fcba19caaeb2a33017459d3430f057967bb91b6 ] As the synproxy infrastructure register netfilter hooks on-demand when a user adds the first iptables target or nftables expression, if done concurrently they can race each other. Introduce a mutex to serialize the refcount control blocks access from both frontends. While a per namespace mutex might be more efficient, it is not needed for target/expression like SYNPROXY. Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: clear the svc scheduler ptr early on edit

2026-06-19T11:21:34+00:00

[ Upstream commit 193989cc6d80dd8e0460fb3992e69fa03bf0ff9b ] ip_vs_edit_service() while unbinding the old scheduler clears the svc->scheduler ptr after the scheduler module initiates RCU callbacks. This can cause packets to use the old scheduler at the time when svc->sched_data is already freed after RCU grace period. Fix it by clearing the ptr early in ip_vs_unbind_scheduler(), before the done_service method schedules any RCU callbacks. Also, if the new scheduler fails to initialize when replacing the old scheduler, try to restore the old scheduler while still returning the error code. Link: https://sashiko.dev/#/patchset/20260519015506.634185-1-rosenp%40gmail.com Fixes: 05f00505a89a ("ipvs: fix crash if scheduler is changed") Signed-off-by: Julian Anastasov Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin