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18 hoursMerge branch 'main' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
19 hoursMerge branch 'for-next' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/mm/linux.git
19 hoursMerge branch 'master' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec.git
19 hoursMerge branch 'main' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
23 hoursMerge https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git ↵David Hildenbrand (Arm)
mm-unstable into for-next Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
24 hourstcp: remove mmap_lock fallback pathDave Hansen
Previously, the per-VMA locking could fail in the face of writers which necessitates a fallback to mmap_lock. The new vma_start_read_unlocked() will wait for writers instead of failing. Use the new helper. Wait for writers. Remove the fallback to mmap_lock. The fallback removal does not affect NOMMU case because TCP_ZEROCOPY is gated on CONFIG_MMU. This really is a nice cleanup. It removes the need to pass the lock state back and forth to find_tcp_vma(). Link: https://lore.kernel.org/20260831203056.838265-6-surenb@google.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Tested-by: syzbot@syzkaller.appspotmail.com Cc: Liam R. Howlett <liam@infradead.org> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Arve Hjønnevåg <arve@android.com> Cc: Todd Kjos <tkjos@android.com> Cc: Christian Brauner <christian@brauner.io> Cc: Carlos Llamas <cmllamas@google.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: David Ahern <dsahern@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
34 hoursMerge tag 'nf-26-09-07' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter/IPVS fixes for net The following patchset contains Netfilter/IPVS fixes for net: 1) Reject malformed messages in IPVS sync, from Kyle Zeng. 2) Fix possible stale infoleak in IPVS sync, also from Kyle Zeng. 3) Out-of-bound read in the SIP conntrack helper, from Joas Antonio dos Santos. 4) UaF on cttimeout module removal, from Chengfeng Ye. 5) Unregister nf_loggers before netns teardown to fix UaF, also from Chengfeng Ye. 6) Fix race in nfnetlink_log due to concurrent instance destruction, from Florian Westphal. 7) Remove arp_table 32bit compat interface, this is already off in many distributions, from Florian Westphal. 8) Set IP6T_F_PROTO flag is e->ipv6.proto is set on to deal with insufficient validation of xtables extensions when used from legacy ip6tables, from Florian. 9) Set on the NLM_F_DUMP_FILTERED flag when all is filtering out in ctnetlink, from Ilya Maximets. * tag 'nf-26-09-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: report NLM_F_DUMP_FILTERED when all is filtered out netfilter: ip6_tables: set F_PROTO when proto value is nonzero netfilter: arp_tables: remove the 32bit compat interface netfilter: nfnetlink_log: cope with concurrent instance destruction netfilter: nf_log: unregister loggers before per-net teardown netfilter: cttimeout: prevent UAF during module unload netfilter: nf_conntrack_sip: fix OOB read in sip_skip_whitespace() ipvs: fix reversed sequence option serialization ipvs: reject invalid states in connection template sync records ==================== Link: https://patch.msgid.link/20260907171732.1407739-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
44 hoursnetlink: specs: fou: link the type attribute to the encap-type enumJakub Kicinski
The spec defines encap-type (unspec / direct / gue), but no attribute references it, so the definition exists only to emit FOU_ENCAP_* into the uAPI header - while FOU_ATTR_TYPE is exactly that value space: fou_create() switches on FOU_ENCAP_DIRECT / FOU_ENCAP_GUE and returns -EINVAL for anything else. Python YNL could not accept or display the names and the generated C exposed a raw __u8 setter. The global policy entry becomes NLA_POLICY_MAX(NLA_U8, 2). For add that only moves the existing fou_create() rejection earlier; del and get ignore FOU_ATTR_TYPE altogether, so a bogus type there now fails validation instead of being dropped on the floor. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Link: https://patch.msgid.link/20260904191412.3872344-4-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
44 hoursnetlink: specs: fou: local-v4 and peer-v4 are big endianJakub Kicinski
fou_core.c uses nla_get_in_addr() / nla_put_in_addr() on both, i.e. they are __be32, and port / peer-port in the same spec are already annotated. Without byte-order YNL swaps them on little endian hosts. The generated policy goes from NLA_U32 to NLA_BE32, which changes nothing: lib/nlattr.c gives the two the same length in nla_attr_len[] and the same range handling, and neither attribute has a range check. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Link: https://patch.msgid.link/20260904191412.3872344-3-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2 daysipv6: Remove IPV6_ADDRFORM.Kuniyuki Iwashima
Recently, IPV6_ADDRFORM has received many AI-driven bug reports. Fixing them properly would needlessly churn the fast paths in TCP and UDP. IPV6_ADDRFORM was initially introduced in RFC 2133 in 1997, but only two years later, it was removed from RFC 2553 in 1999. In 2026, modern applications natively support dual-stack sockets; notably, systemd's socket activation does not use IPV6_ADDRFORM. Also, getsockopt(IPV6_ADDRFORM) can be replaced with SO_DOMAIN. Let's remove IPV6_ADDRFORM. Later, we can remove sk->sk_prot_creator and revert commit c26c192c3d48 ("udp: properly deal with xfrm encap and ADDRFORM"). Reported-by: Daehyeon Ko <4ncienth@gmail.com> Closes: https://lore.kernel.org/netdev/20260902010408.1057857-1-4ncienth@gmail.com/ Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Closes: https://lore.kernel.org/netdev/20260824033331.1084971-1-imv4bel@gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260904033543.2635540-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2 daystcp: Do not allow buggy transitions between ehash and lhash2.Kuniyuki Iwashima
The following state transitions have long been a playground for syzbot, and recently AI joined in, reporting a lot more bugs. * listen() + shutdown() + connect() * connect() + connect(AF_UNSPEC) + listen() All the fix attempts would add more code to the fast path, which is not worth it. Instead of playing whack-a-mole with these edge-case bugs, let's disallow these transitions. Note that unhashed_state is placed in the 4-byte hole after icsk_pmtu_cookie. $ pahole -C inet_connection_sock vmlinux struct inet_connection_sock { ... __u32 icsk_pmtu_cookie; /* 1208 4 */ unsigned char unhashed_state; /* 1212 1 */ /* XXX 3 bytes hole, try to pack */ Reported-by: Kyle Zeng <kylebot@openai.com> Closes: https://lore.kernel.org/netdev/20260731140512.566464-1-david.lee@trailofbits.com/ Reported-by: Michal Luczaj <mhal@rbox.co> Closes: https://lore.kernel.org/netdev/20260803-sockmap-lookup-tcp-leak-v2-0-306e025bfe66@rbox.co/ Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Closes: https://lore.kernel.org/netdev/20260824033331.1084971-1-imv4bel@gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260904033543.2635540-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2 daysnet: ipv4: Fix UDP length overflow with PMTU discover and big MTUAlice Mikityanska
This commit bounds cork->base.fragsize to IP_MAX_MTU to avoid a possible overflow of UDP length that triggers a WARN in udp_set_len_short when setsockopt IP_MTU_DISCOVER is set to IP_PMTUDISC_PROBE, and a large packet is sent over a netdev with an unusually large MTU. Steps to reproduce: 1. Set device MTU bigger than IP_MAX_MTU + 20. cork->base.fragsize will be set to that MTU in ip_setup_cork. 2. Set IP_MTU_DISCOVER to IP_PMTUDISC_PROBE. It lets maxnonfragsize be set to device MTU (cork->fragsize) in __ip_append_data, rather than to IP_MAX_MTU. 3. Send 65528 bytes of payload (+8 bytes of UDP header, +20 bytes of IPv4 header). Device MTU allows it (it's only one byte bigger than IP_MAX_MTU + IPv4 header, and the device MTU is bigger than that). 4. The UDP length in the built packet is 65536, which overflows the 16-bit length field and triggers the WARN in udp_set_len_short. Note: IP_PMTUDISC_DO with IPv4 is safe, because ip_dst_mtu_maybe_forward always clamps at IP_MAX_MTU, unlike ip6_dst_mtu_maybe_forward. The Fixes tag points at the first commit where I could reproduce the overflow with IPv4 and IP_PMTUDISC_PROBE. Fixes: daba287b299e ("ipv4: fix DO and PROBE pmtu mode regarding local fragmentation with UFO/CORK") Reported-by: syzbot+ce13c07d96d04716eaa2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a6a966c.86abc875.e5c3d.0054.GAE@google.com/ Signed-off-by: Alice Mikityanska <alice@isovalent.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260901195714.673548-2-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
3 daysnetfilter: arp_tables: remove the 32bit compat interfaceFlorian Westphal
This feature is required to use 32bit arptables binary on 64bit kernels. It's already off in many distributions including Debian and Fedora for many years. Zap arptables first, it's the most esoteric of the 4 flavors. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
5 daysbpf: make tcp_tso_autosize() available to BPF congestion controlsChia-Yu Chang
Expose tcp_tso_autosize() as a BPF kfunc and register it in the TCP congestion-control kfunc set. This allows BPF congestion controls to reuse the kernel TSO autosizing logic while applying their own minimum TSO segment policy. To make the kfunc robust against BPF-provided inputs, min_tso_segs is sanitized to at least 1 and mss_now == 0 returns the sanitized minimum value instead of performing autosizing. Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daystcp: Replace min_tso_segs() with tso_segs() CC callbackChia-Yu Chang
This patch replaces the existing min_tso_segs() callback with a new tso_segs() callback, allowing congestion control algorithms to provide an explicit TSO segment count for each data burst and bypass tcp_tso_autosize(). The resulting tso_segs value is clamped to [1, sk->sk_gso_max_segs], preventing congestion-control implementations from returning an invalid zero-segment value. This change has the following impacts on BPF struct_ops users: - The callback is renamed from min_tso_segs() to tso_segs() - The signature gains an extra u32 mss_now argument - The return value semantics is changed from "floor value passed into tcp_tso_autosize()" to "final tso_segs value", bypassing autosizing As a result, existing BPF programs must be updated, because returning a small constant will now directly limit the final tso_segs value instead of specifying the minimum value passed to tcp_tso_autosize(). Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Ilpo Järvinen <ij@kernel.org> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daystreewide: refresh kmalloc_obj() conversionsKees Cook
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
5 daysnexthop: Initialize extack in remove_nh_grp_entry()Ido Schimmel
remove_nh_grp_entry() prints the extack message when a listener fails to replace the reduced nexthop group. However, extack is not initialized and listeners are not required to set a message when returning an error. Neither netdevsim nor mlxsw do so when an allocation fails, resulting in the dereference of an uninitialized stack pointer. Fix by zero-initializing extack, as was done in commit 6347c5314cee ("nexthop: initialize extack in nh_res_bucket_migrate()"). Fixes: 833a1065eeb1 ("nexthop: Emit a notification when a nexthop group is reduced") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260903080259.10378-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysneighbour: Don't store net in struct pneigh_entry.Kuniyuki Iwashima
neigh_table is now per-netns, so struct pneigh_entry does not need to store a net pointer. Let's remove it and net comparison for pneigh_entry. We no longer need to pass net to pneigh_create(), pneigh_delete(), and pneigh_lookup(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-14-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysneighbour: Namespacify neigh_tables.Kuniyuki Iwashima
Now, neigh_table is ready to be namespacified. Let's allocate per-netns neigh_table in neigh_table_register() and call neigh_table_init() and neigh_sysctl_register() for it. proc_create_seq_data() is changed to proc_create_net_data(). Since each netns has its own sysctl knobs, RTM_SETNEIGHTBL can configure the default table param (ifindex==0) and GC parameters per netns. To avoid potential regression, all the default parameters under /proc/sys/net/ipv{4,6}/neigh/default/, are inherited from init_net by default. This behaviour is controlled by a new sysctl knob, net.core.neigh_inherit_init_net: # sysctl net.core.neigh_inherit_init_net net.core.neigh_inherit_init_net = 1 # sysctl net.ipv4.neigh.default.gc_thresh1 net.ipv4.neigh.default.gc_thresh1 = 128 # sysctl net.ipv4.neigh.default.gc_thresh1=129 net.ipv4.neigh.default.gc_thresh1 = 129 # unshare -n sysctl net.ipv4.neigh.default.gc_thresh1 net.ipv4.neigh.default.gc_thresh1 = 129 If it is turned off, all settings are reset in the new netns: # sysctl net.core.neigh_inherit_init_net=0 net.core.neigh_inherit_init_net = 0 # unshare -n sysctl net.ipv4.neigh.default.gc_thresh1 net.ipv4.neigh.default.gc_thresh1 = 128 The next patch will remove other unnecessary net_eq(). Note that CONFIG_SYSCTL cannot be enabled without CONFIG_PROC_FS. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-13-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysipv6: Replace &nd_tbl with nd_table(net).Kuniyuki Iwashima
We will allocate per-netns neigh_table in net->neigh_tables[]. Let's replace &nd_tbl with nd_table(net). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-10-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysipv4: Replace &arp_tbl with arp_table(net).Kuniyuki Iwashima
We will allocate per-netns neigh_table in net->neigh_tables[]. Let's replace &arp_tbl with arp_table(net) and remove extern definition for arp_tbl. Three notes: 1. mlx5e_rep_netevent_event() and nfp_tun_neigh_event_handler() have code assuming neigh_table other than &arp_tbl and &nb_tbl, and the part is removed as it will be false once per-netns table is allocated. 2. prestera and rocker uses init_net because they set dev->netns_immutable to true. 3. mlx5e_tc_update_neigh_used_value() dereferences nhe->neigh_dev in trace_mlx5e_tc_update_neigh_used_value(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-9-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysneighbour: Remove neigh_tables[].Kuniyuki Iwashima
Now, &arp_tbl and &nd_tbl are stored in net->neigh_tables[]. Let's use net->neigh_tables[] in neighbour.c and remove the global neigh_tables[]. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysneighbour: Store arp_tbl and nd_tbl in net->neigh_tables[].Kuniyuki Iwashima
We will remove RTNL for neigh_add() and neigh_delete(), but they are still serialised by per-protocol neigh_table.lock. We can avoid contention by converting neigh_tables[] to per-netns, but arp_tbl and nd_tbl are directly used in many places. As a prep, let's store &arp_tbl and &nd_tbl in net->neigh_tables[]. We will replace such users with arp_table(net) and nd_table(net) and then allocate per-netns neigh_table. Note that nd_table() still returns &nd_tbl in case disable_ipv6_mod is 1 because some buggy drivers use nd_tbl without checking it. proc_create_net() is guarded with CONFIG_PROC_FS because it returns NULL when =n and setup_net() fails and panic()s. Also a later patch moves neigh_sysctl_register() under the guard. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
6 daystunnels: Drop stale dst when building an ICMP error for PMTUDIdo Schimmel
Bridged UDP tunnels such as VXLAN and GENEVE build an ICMP error packet around an overlay packet if the packet is going to exceed the underlay path MTU. The ICMP error packet is then injected back into the Rx path with the source and destination addresses swapped, so that it will be delivered to the overlay source. If the overlay packet was routed to the UDP tunnel or locally generated, then it is already carrying a valid dst entry and this entry is not dropped when transforming the packet to an ICMP error packet. This causes the IP layer to reuse the dst entry, leading to the ICMP error packet being dropped or routed out of the UDP tunnel interface in case of forwarding. Prior to the blamed commit this could not happen, as skb_tunnel_check_pmtu() did not build ICMP errors for PACKET_HOST packets. Such packets were instead encapsulated and, unless the DF bit was set in the outer header, fragmented by the underlay. Fix this by making sure that the ICMP error packet does not have a valid dst entry, thereby forcing the IP layer to perform a route lookup. Adjust the bridged PMTU exception selftests accordingly. When the local sender in ns_a pings the overlay destination with a deadline (-w), ping exits on the first socket error before any reply is received and returns a non-zero exit code. The test therefore only passed because the ICMP error was never delivered. Use a packet count (-c) like the ns_c line above it, so that the ICMP error counts against the packet budget and the exit code depends on whether echo replies were received. This passes with and without the fix. Fixes: 8930424777e4 ("tunnels: Accept PACKET_HOST in skb_tunnel_check_pmtu().") Cc: stable@vger.kernel.org Reported-by: Laika Price <laikabcprice@gmail.com> Closes: https://lore.kernel.org/netdev/20260614-master-v3-1-9f5060ba1ed1@gmail.com/ Reported-by: Yaroslav Dudkov <aroslavdudkov622@gmail.com> Closes: https://lore.kernel.org/netdev/20260901081825.287173-1-aroslavdudkov622@gmail.com/ Reported-by: Charles Bordet <rough.rock3059@datachamp.fr> Closes: https://lore.kernel.org/netdev/aHVhQLPJIhq-SYPM@eldamar.lan/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Yaroslav Dudkov <aroslavdudkov622@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20260902190112.4126199-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
6 daysipv4: fib: bound automatic table ID allocationZihan Xi
fib_empty_table() probes every table ID from 1 until it finds a free one. IPv4 tables are stored in a 256-bucket hash table, so a dense set of IDs makes each probe walk a growing hash chain while RTNL is held. Automatic table assignment ("ip rule ... table 0") is an IPv4-only legacy path. Bound the automatically allocated ID to 4096 so the RTNL hold stays bounded, without changing lookups of explicitly specified table IDs. This changes user-visible behavior. A table-0 rule previously received the lowest free ID in 1..RT_TABLE_MAX (0xFFFFFFFF). After this patch the search stops at 4096 and the rule add fails with ENOBUFS if that range is fully occupied. Explicit table IDs above 4096 remain usable. The automatic path is unused in practice: it is IPv4-only, not documented by ip-rule, uncovered by kernel selftests, and both NetworkManager and systemd refuse table 0. Fixes: b801f54917b7 ("[NET]: Increate RT_TABLE_MAX to 2^32") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Vorel <pvorel@suse.cz> Link: https://patch.msgid.link/6f2f2a7a136aee005512a2e1ac8ede62ac8c7bb6.1788258884.git.zihanx@nebusec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org>
7 daysMerge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.3-rc2). No conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
7 daysnet: gro: Fix nesting of TCP GSO SKBs in skb_gro_receive_list()HW He
Fraglist GRO and hardware GRO can create an fraglist of HW-GRO packets. This cannot be segmented back into the original form on TCP tethering scenario. Avoid constructing such a GSO packet, by flushing an already built fraglist GRO packet if a hardware GRO packet arrives. Scenario (Tethering/Forwarding): 1.Driver submits a single TCP packet, P1. P1 is kept in the gro_list as the first packet. 2. The driver submits a TCP GSO skb, P2. P2 has already aggregated multiple TCP packets by HW_GRO, and its non-linear data is stored in frags[]. 3. P1 and P2 match the GRO rules, and since there is no local socket, they are aggregated by skb_gro_receive_list(). The resulting skb, P3, has a frag_list entry that still contains frags[]: P3: [ Linear Data ] -> frag_list -> [ Linear Data ] [ frag[1] ] [ frag[2] ] ... 4. Later, tcp4_gso_segment() or tcp6_gso_segment() calls skb_segment_list() to segment P3. However, skb_segment_list() only segments the entries in frag_list. It does not segment the frags[] inside P2, so P3 is not restored to the original packets, which leads to IP fragmentation or packet drop in the following path. Check skb_is_gso(skb) and current GRO method, make sure fraglist GRO applies to consecutive non-GSO skb, others adopt regular GRO path. Fixes: 8d95dc474f85 ("net: add code for TCP fraglist GRO") Signed-off-by: Zhaoping Shu <zhaoping.shu@mediatek.com> Signed-off-by: HW He <hw.he@mediatek.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260901082312.14596-1-zhaoping.shu@mediatek.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
7 daysnet: Replace %pK output with 0Sebastian Andrzej Siewior
Commit 71338aa7d050c ("net: convert %p usage to %pK") which is from 2011 and changed the %p annotation for pointer to %pK. Back then the default behaviour for %p was to print the pointer. The %pK modifier was introduced to able to control the behaviour of specific pointer values without changing the behaviour of %p for everyone. It was dedicated to avoid leaking pointers via /proc. There was also the idea to remove the check from formatting the string and move to the open callback with some helpers but this did not happen. Things changed over time. The default behaviour for %p is now to print a hash pointer which does not leak the address but allows to correlate if two pointers are equal. The policy on %p is to not introduce new ones. This is somehow in between since it already exists. The pointer are usually socket pointers and I don't see any value in exposing them. Therefore I am following the recommendation of removing them. Since their usage in /proc/ can be considered ABI I replace the pointer with a 0. Replace the %pK annotation with 0 value. Correct the spacing for the cases where pointer is at the beginning. Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20260901160345.eeknHmY2@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
9 daysipv4: udp: Create exceptions before socket matchingIdo Schimmel
Currently, when ICMP Fragmentation Needed and Redirect Message packets are locally delivered and quote a UDP packet, a FIB nexthop exception (FNHE) is only created if the kernel can match the UDP packet to an existing socket. This behavior allows off-path attackers to conduct a side-channel attack on the FNHE cache in order to discover the ephemeral port used by a connected UDP socket. Commit 6457378fe796 ("ipv4: use siphash instead of Jenkins in fnhe_hashfun()") and commit 67d6d681e15b ("ipv4: make exception cache less predictible") tried to mitigate such attacks by making it harder for attackers to discover hash collisions in the FNHE cache and by randomizing the number of exceptions a hash bucket can hold, respectively. Unfortunately, both of the mitigations can be bypassed. Instead, mitigate such attacks by always creating a FNHE, even before trying to find a matching socket. Do that by calling ipv4_update_pmtu() and ipv4_redirect(), the helpers used when the quoted packet did not originate from a socket. This means that guesses (right or wrong) from an off-path attacker will always result in a FNHE being created or updated in the cache that the attacker can observe. Pass an oif of 0, in a similar fashion to icmp_err(). This is also the oif used by the socket path for sockets that are not bound to a device. Note that this does not allow attackers to create FNHEs that they could not create before, as both helpers can already be reached with little to no validation. For example, by sending an ICMP error that quotes an ICMP Echo Reply or one that quotes a UDP source port that matches a wildcard socket. Also note that in the good case (matched socket) the above scheme comes at the cost of an extra route lookup, as the no socket helpers perform their own lookup before the one performed by ipv4_sk_update_pmtu() / ipv4_sk_redirect(). When the two resolve to different nexthops, it also results in two exceptions being created for the same destination IP. One in the FNHE cache of the nexthop resolved by the no socket helpers and another in the FNHE cache of the nexthop used by the socket. Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.") Cc: stable@vger.kernel.org Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Noam Caspi <noam.caspi@mail.huji.ac.il> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260828192344.2596928-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
9 daysigmp: convert struct ip_sf_list to RCUEric Dumazet
Commit 23d2b94043ca ("igmp: Add ip_mc_list lock in ip_check_mc_rcu") added spin_lock_bh(&im->lock) to ip_check_mc_rcu() to prevent a use-after-free while iterating im->sources during concurrent deletions. However, ip_check_mc_rcu() is called from RCU read-side critical sections in packet receive and route lookup fast paths (e.g. __mkroute_output(), ip_route_input_rcu(), and __udp4_lib_rcv()). When igmpv3_send_cr() or igmpv3_send_report() holds &pmc->lock and calls add_grec() -> igmpv3_newpack() -> ip_route_output_ports(), an XFRM policy matching a multicast destination triggers xfrm_tmpl_resolve_one() -> xfrm4_get_saddr() -> __mkroute_output() -> ip_check_mc_rcu(). This attempts to acquire &im->lock while &pmc->lock is already held on the same CPU, triggering a lockdep recursive locking warning / deadlock. Fix this by converting IPv4 struct ip_sf_list to RCU, mirroring the IPv6 implementation in net/ipv6/mcast.c: 1. Add struct rcu_head to struct ip_sf_list and annotate sf_next, sources, and tomb as __rcu pointers. 2. Use rcu_assign_pointer() and kfree_rcu() for list updates and deletions. 3. Remove spin_lock_bh(&im->lock) from ip_check_mc_rcu() and traverse im->sources locklessly with for_each_psf_rcu(), reading and writing counter fields with READ_ONCE() and WRITE_ONCE(). Note: RCU conversion of /proc/net/mcfilter will be done in a separate patch. Fixes: 23d2b94043ca ("igmp: Add ip_mc_list lock in ip_check_mc_rcu") Reported-by: syzbot+3d99fb01bcd740f2fc1e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3d99fb01bcd740f2fc1e Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260827160656.903003-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
10 daysraw: annotate disconnect-side IPv4 match writersXuanqiang Luo
raw_v4_match() reads inet_daddr, inet_rcv_saddr and sk_bound_dev_if locklessly under RCU. Bind and connect writers are annotated, but __udp_disconnect() still clears the same fields using plain stores. Commit 18f116931f52e ("raw: annotate lockless match fields in raw_v4_match()") added the lockless readers and annotated the raw bind and datagram connect writers. Its v4 revision intentionally left the shared disconnect-side IPv4 writers for follow-up cleanup. Complete that follow-up by using WRITE_ONCE() for the disconnect-side stores, including the inet_rcv_saddr reset in inet_reset_saddr(), to pair with the lockless raw socket matcher. Fixes: 0daf07e52709 ("raw: convert raw sockets to RCU") Link: https://lore.kernel.org/netdev/20260716142958.3064224-1-runyu.xiao@seu.edu.cn/ Suggested-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260828012918.1461-1-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
12 daystcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO)Cen Zhang (Microsoft Security FORGE Labs)
do_tcp_getsockopt() reads icsk->icsk_ca_ops and dereferences the get_info function pointer without rcu_read_lock(). With BPF struct_ops congestion control, ca_ops can point to dynamically allocated memory that is freed concurrently, resulting in a use-after-free when the kernel dereferences or calls through the stale pointer. BUG: KASAN: slab-use-after-free in do_tcp_getsockopt+0x2037/0x23e0 Read of size 8 at addr ffff888013701258 by task exploit/149 do_tcp_getsockopt+0x2037/0x23e0 (net/ipv4/tcp.c:4564) tcp_getsockopt+0x91/0xf0 __sys_getsockopt+0xf7/0x170 Fix this by wrapping the ca_ops load and get_info call within rcu_read_lock()/rcu_read_unlock(), and using READ_ONCE() to load the icsk_ca_ops pointer. Fixes: 0baf26b0fcd7 ("bpf: tcp: Support tcp_congestion_ops in bpf") Suggested-by: Eric Dumazet <edumazet@google.com> Cc: AutonomousCodeSecurity@microsoft.com Cc: stable@vger.kernel.org Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) <blbllhy@gmail.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/65fd3816ed5d541d9edd4bf4fcf97104a2cf907a.1787870710.git.blbllhy@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
12 daystcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION)Cen Zhang (Microsoft Security FORGE Labs)
do_tcp_getsockopt() reads icsk->icsk_ca_ops->name without holding rcu_read_lock(). Since commit 0baf26b0fcd7 ("bpf: tcp: Support tcp_congestion_ops in bpf"), icsk_ca_ops can point to dynamically allocated BPF struct_ops memory that may be freed concurrently via setsockopt(TCP_CONGESTION), leading to a use-after-free. BUG: KASAN: slab-use-after-free in _copy_to_user+0x37/0x60 Read of size 16 at addr ffff888013505260 by task exploit/149 _copy_to_user+0x37/0x60 do_tcp_getsockopt+0x158a/0x2460 (net/ipv4/tcp.c:4585) tcp_getsockopt+0x91/0xf0 __sys_getsockopt+0xf7/0x170 Fix this by holding rcu_read_lock() around the ca_ops->name access, using READ_ONCE() to load icsk_ca_ops, and copying the name to a stack buffer before releasing the lock. Also annotate the relevant icsk_ca_ops stores with WRITE_ONCE() to fix the accompanying KCSAN data-race issue. Fixes: 0baf26b0fcd7 ("bpf: tcp: Support tcp_congestion_ops in bpf") Suggested-by: Eric Dumazet <edumazet@google.com> Reported-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Link: https://lore.kernel.org/all/20260821182449.79785-2-blbllhy@gmail.com/ Cc: AutonomousCodeSecurity@microsoft.com Cc: stable@vger.kernel.org Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) <blbllhy@gmail.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/d3f97f1acbf0010898148be6e6406e4b8b4a5c84.1787870710.git.blbllhy@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
12 daystcp: use GFP_ATOMIC in tcp_send_active_reset()Eric Dumazet
tcp_send_active_reset() can be called from contexts where gfp_any() (in tcp_disconnect()) or sk->sk_allocation (in __tcp_close() and mptcp_do_fastclose()) evaluates to GFP_KERNEL, which includes __GFP_FS and __GFP_DIRECT_RECLAIM. Allocating with GFP_KERNEL while holding the socket lock (sk_lock) creates a lockdep dependency: sk_lock -> fs_reclaim This causes false-positive lockdep circular locking warnings with storage subsystems (such as nvme-tcp) that acquire socket locks in block I/O paths and invoke tcp_disconnect() or close sockets upon teardown: set->srcu -> sk_lock -> fs_reclaim -> elevator_lock -> set->srcu Active resets are small RST packet headers that should never enter direct reclaim or block while holding socket locks. Use sk_gfp_mask(sk, GFP_ATOMIC | __GFP_NOWARN) inside tcp_send_active_reset() and remove its priority argument. This preserves __GFP_MEMALLOC access for SOCK_MEMALLOC sockets, suppresses allocation failure warnings, and aligns with other control packet allocations (e.g. tcp_send_fin(), __tcp_send_ack(), tcp_xmit_probe_skb()). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20260827095936.551524-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
12 daysipv4: avoid divide by zero in fib_rebalanceZihan Xi
fib_rebalance() computes the total eligible nexthop weight in one pass and programs upper bounds in a second pass. A concurrent change to ignore_routes_with_linkdown can make the first pass return zero while the second pass sees an eligible nexthop, resulting in division by zero. If the first pass reports a zero total, set each nexthop upper bound to -1 and skip the division. This matches the IPv6 fix in commit d2c26c2911dd ("ipv6: avoid divide by zero in rt6_multipath_rebalance") and preserves the lock-free rebalance path. Fixes: 0e884c78ee19 ("ipv4: L3 hash-based multipath") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260827182514.4667-2-zihanx@nebusec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org>
13 daysMerge tag 'nf-26-08-27' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net: 1) Use DEBUG_NET_WARN_ON_ONCE() instead of WARN_ON() from the tproxy datapath, a recent bug found a way to reach WARN_ON from datapath due to insufficient validation of xt_TPROTO checkentry. From Fernando F. Mancera. 2) Similar to previous patch to replace WARN_ON_ONCE by DEBUG_NET_WARN_ON_ONCE() for connlimit. Not known issue, but since this patch has been around for a while, let's merge it. Also from Fernando. 3) Move nf_tables harware offload commit path after chain blob and audit to reduce chances of leaving the hardware in inconsistent state. 4) Add missing vzeroupper to nf_tables pipapo AVX2 to address performace degradation to later user of SSE code, from Eric Biggers. 5) Remove pr_debug() in x_tables extensions, a recent bogus found a way to print a unsanitized string in xt_IDLETIMER, many of these pr_debug() calls are there for historical reasons. 6) Use pr_info_ratelimited() in x_tables .checkentry. 7) Fix an imbalance in module refcount due to incorrect override expression logic with sets. Remove unnecessary clone in control plane, use the existing expressions provided by set or dynset expression. Release override expressions only. 8) Tigthen nf_tables device name removal, it is possible to remove prefix strings with exact device name. From Fernando F. Mancera. 9) Set on the set dead bit earlier, otherwise it is possible to call .commit on deleted sets. This also addresses the re-introduction of a bug. * tag 'nf-26-08-27' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nf_tables: remove leftover set_update_list netfilter: nf_tables: set on dead bit when performing early element removal netfilter: nf_tables: skip double clone set expressions on element insert netfilter: x_tables: replace pr_{info,err}() by pr_info_ratelimited() netfilter: x_tables: remove pr_debug netfilter: nft_set_pipapo_avx2: add missing vzeroupper netfilter: nf_tables: move hardware offload step after building the chain blob netfilter: conncount: use DEBUG_NET_WARN_ON_ONCE on reaching count limit netfilter: tproxy: use DEBUG_NET_WARN_ON_ONCE for protocol fallbacks ==================== Link: https://patch.msgid.link/20260827141733.423453-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
13 daysinet: frags: strip GSO state from fragments before reassemblyXinyang Ge
A virtio_net_hdr (tun/tap, or AF_PACKET with PACKET_VNET_HDR) can mark an IPv4 or IPv6 fragment as GSO; nothing relates gso_type to frag_off. inet_frag_reasm_prepare()/inet_frag_reasm_finish() keep the first fragment's skb as the head of the reassembled datagram, including its shinfo->gso_size/gso_type/gso_segs, and chain the remaining fragments on frag_list with whatever linear/paged layout they arrived with. After ip_defrag() (ip_local_deliver(), nf_defrag_ipv4, ...) the reassembled skb therefore still claims to be GSO (SKB_GSO_DODGY), and the next software segmentation point - udp_rcv_segment() on local delivery, validate_xmit_skb(), or the ip_finish_output_gso() slow path - hands it to skb_segment(). skb_segment()'s frag_list walk assumes GRO-shaped input and hits one of its BUG_ON()s. Two writes to a tap by an unprivileged user in its own userns are enough: kernel BUG at net/core/skbuff.c:4899! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 1000 PID: 82 Comm: poc Not tainted 7.2.0-pentest+ #2 RIP: 0010:skb_segment+0x20ca/0x48b0 Call Trace: <TASK> __udp_gso_segment+0x29a/0x27d0 udp4_ufo_fragment+0x458/0x6c0 inet_gso_segment+0x429/0x1340 skb_mac_gso_segment+0x233/0x4f0 __skb_gso_segment+0x308/0x660 udp_queue_rcv_skb+0x440/0xad0 udp_unicast_rcv_skb+0xc7/0x2c0 udp_rcv+0x16ce/0x2260 ip_protocol_deliver_rcu+0x197/0x2d0 ip_local_deliver+0x430/0x690 ip_rcv+0x16f/0x1f0 __netif_receive_skb_one_core+0x15e/0x1c0 __netif_receive_skb+0x1e/0x110 netif_receive_skb+0xf6/0x5c0 tun_rx_batched.isra.0+0x3ab/0x790 tun_get_user+0x17c3/0x3550 tun_chr_write_iter+0xba/0x1b0 vfs_write+0x646/0x1130 </TASK> Kernel panic - not syncing: Fatal exception in interrupt This runs with BH disabled, so it is a panic rather than an oops. The same is reachable with CAP_NET_RAW in a netns where a defrag point precedes a GSO point, and from a guest whose VMM forwards virtio_net_hdr to a tap. The SKB_GSO_DODGY frag_list checks added by commit 3dcbdb134f32 ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list") and by commit 9e4b7a99a03a ("net: gso: fix panic on frag_list with mixed head alloc types") do not cover it: page-backed heads skip them, and kmalloc heads skip them when gso_size == skb_headlen(head), which the sender controls. An skb entering a frag queue is an IP fragment by definition and cannot legitimately carry GSO state: GRO does not merge fragments and the stack segments before it fragments, so only untrusted sources are affected. This has been reachable since commit f43798c27684 ("tun: Allow GSO using virtio_net_hdr"), the first path that let userspace attach GSO metadata to an IP fragment. Reset the GSO fields of every fragment as it is queued, in inet_frag_queue_insert(), which IPv4, IPv6, nf_conntrack_reasm and 6lowpan reassembly share; then neither the head nor the frag_list members of the reassembled skb carry them (the members matter too: the ip_do_fragment()/ip6_fragment() fast paths send them out as they are). The head may remain CHECKSUM_PARTIAL; that is already accepted on receive and resolved by skb_checksum_help() in ip_do_fragment()/ip6_fragment() on forward. Tested on top of net.git (dc4b95b8fee9), x86_64: the tap reproducer above, two further IPv4 frag_list geometries that reach BUG_ON(i >= nfrags) and BUG_ON(!list_skb->head_frag), and an IPv6 fragment-header variant (udp6_ufo_fragment()) each panic the unpatched kernel; with this patch all four datagrams are delivered intact and nothing is logged. Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr") Cc: stable@kernel.org Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Xinyang Ge <xinyang@anthropic.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/937926e509f2acd8e0e66520dc2b30fd6b4d1687.1787839506.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
13 daystcp: fix corruption of urgent data on multi-segment retransmitJiayuan Chen
On the normal xmit path, while in urgent mode we refuse to build a multi-segment TSO packet, so every segment gets its own urg_ptr: /* tcp_write_xmit() */ limit = mss_now; if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(...); The retransmit path has no such guard. __tcp_retransmit_skb() builds a segs > 1 skb and hands it to the GSO layer, which only advances th->seq per segment and copies urg_ptr verbatim: /* __tcp_retransmit_skb() */ len = cur_mss * segs; /* segs > 1, no urg_mode check */ ... /* tcp_gso_segment(): bumps seq only, urg_ptr is copied */ urg_ptr is an offset from the segment's own seq, so a copied value points at a different place on each segment. The receiver rebuilds the absolute urgent seq as seg.seq + urg_ptr, so it walks a moving urgent point instead of the one OOB byte: seg1 seq 1 urg_ptr 5001 -> urgent @ 5001 (ok) seg2 seq 1001 urg_ptr 5001 -> urgent @ 6001 (wrong, +MSS) seg3 seq 2001 urg_ptr 5001 -> urgent @ 7001 (wrong, +2*MSS) The real OOB byte is never pointed at, so the receiver stops splicing it out and delivers it as normal in-band data, corrupting the stream. Guard the retransmit length like the xmit path: keep segs = 1 while in urgent mode. Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time") Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260826141145.67823-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
14 daysnetfilter: x_tables: remove pr_debugPablo Neira Ayuso
Remove pr_debug() for these xtables extensions, these have no use these days. Still, turn pr_debug() into pr_info_ratelimited() in the .checkentry path since this helps provide a hint via dmesg in legacy iptables. Exception is xt_IDLETIMER in the module init path, where pr_err() is used. Add missing pr_fmt() definition in xt_REDIRECT, xt_NETMAP and xt_MASQUERADE. Add missing \n to several pr_debug() that were translated to use pr_info_ratelimited(). Link: https://patch.msgid.link/cover.1786933680.git.rakukuip@gmail.com/ Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
14 daysnetfilter: tproxy: use DEBUG_NET_WARN_ON_ONCE for protocol fallbacksFernando Fernandez Mancera
Replace WARN_ON calls with DEBUG_NET_WARN_ON_ONCE in the default switch blocks of nf_tproxy_get_sock_v4 and v6. Unsupported transport protocols are already safely handled by returning a NULL socket pointer. This prevents unnecessary system panics when panic_on_warn=1 is enabled in production systems. Link: https://patch.msgid.link/cover.1786968834.git.zhilinz@nebusec.ai/ Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
14 daystcp: fix AO info use-after-free in tcp_ao_connect_init()Qing Ming
tcp_v4_connect() adds a SYN-SENT socket to the ehash before calling tcp_connect(). If TCP-AO is configured, tcp_connect() first verifies that a key matches the peer and the bound device's current L3 master. tcp_ao_connect_init() later resolves the L3 master again and removes keys which do not match it. The socket lock does not stabilize the bound device's VRF membership. Detaching the device from its VRF between the initial validation and the L3-master calculation in tcp_ao_connect_init() can therefore make the validation succeed while initialization observes the default L3 domain and removes the only key. The subsequent AO lookup then fails, so the no-key path clears tp->ao_info and frees it directly. The receive path can find the socket in the ehash and load tp->ao_info under RCU before acquiring the socket lock. A reader which loaded the old pointer can thus continue into tcp_inbound_ao_hash() after the direct free. The issue was found during a static audit of TCP-AO object lifetime. An unprivileged reproducer in self-created user and network namespaces raced connect() with detaching a veth from its VRF while sending TCP-AO segments. It triggered the same KASAN report on two fresh boots: BUG: KASAN: slab-use-after-free in tcp_inbound_ao_hash+0x585/0x19f0 Write of size 8 at addr ffff88800bf88128 by task tcp_ao_vrf_race/232 Call Trace: tcp_inbound_ao_hash+0x585/0x19f0 tcp_inbound_hash+0x677/0xa80 tcp_v4_rcv+0x1c3e/0x3ab0 Allocated by task 235: tcp_ao_alloc_info+0x43/0xf0 tcp_ao_add_cmd+0xdf7/0x13b0 do_tcp_setsockopt+0x168c/0x2640 Freed by task 235: kfree+0x1b8/0x550 tcp_connect+0x252/0x4f00 tcp_v4_connect+0x1114/0x1720 The bad address is 40 bytes inside the freed 128-byte object, matching the tcp_ao_info counters.key_not_found field. The two runs used 1000 attempts each, reached the no-key path 366 and 411 times, and produced one and two KASAN reports respectively. With this change, the same reproducer reached the no-key path 366 times in 1000 attempts without a KASAN report or oops. Use tcp_ao_destroy_sock() for the no-key path. It unpublishes the AO info, updates the socket memory and static-key accounting, and defers the free until after an RCU grace period. Also drop the WARN_ON_ONCE() and its stale comment. The VRF detach race makes the no-key state reachable during normal operation, so it is a handled condition rather than an impossible assertion. On panic_on_warn kernels the WARN would turn this handled race into a kernel panic. Fixes: 248411b8cb89 ("net/tcp: Wire up l3index to TCP-AO") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5 Signed-off-by: Qing Ming <a0yami@mailbox.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260825072033.6921-1-a0yami@mailbox.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
14 daysnet/tcp: fix TCP-AO key deletion in VRFsRastislav Szabo
TCP-AO keys with TCP_AO_KEYF_IFINDEX store the VRF L3 interface index in l3index. tcp_ao_del_cmd() validates the supplied ifindex, but does not assign it to its local l3index before matching keys. As a result, deleting a key scoped to a non-default VRF always fails with ENOENT because it is matched against l3index 0. Fixes: 248411b8cb89 ("net/tcp: Wire up l3index to TCP-AO") Cc: stable@vger.kernel.org Signed-off-by: Rastislav Szabo <rastislav.szabo@isovalent.com> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20260822201119.272269-1-rastislav.szabo@isovalent.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-24esp: downgrade zerocopy managed frags before mutating skb fragsMaher Azzouzi
On the out-of-place output path (esp->inplace == false) ESP rewrites the skb frag array: esp_output_head() appends a trailer frag and esp_output_tail() replaces the frags with a destination page, both referenced with get_page(). When the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the payload frags are owned by the ubuf and must not be referenced or unreferenced individually, but ESP mutates the frag array without ever downgrading the skb. This breaks the managed-frag invariant two ways: - esp_ssg_unref() walks the source scatterlist and drops a page reference for every frag, including the ubuf-owned payload frags, pushing their refcount below the GUP pin bias while the pages are still pinned, i.e. a use-after-free of the zerocopy pages; - esp_output_tail() installs its destination page as frag 0 with get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so skb_release_data() takes the skip_unref branch and never drops that reference, leaking the x->xfrag page at packet rate. Fix this the way every other frag-mutating site does (__ip_append_data(), __ip6_append_data(), tcp_sendmsg_locked()) and call skb_zcopy_downgrade_managed() before ESP touches the frag array: it takes a real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS, so the per-frag unref in esp_ssg_unref() and the frag release in skb_release_data() are both balanced and no mixed-ownership frag array is left behind. Fixes: 753f1ca4e1e5 ("net: introduce managed frags infrastructure") Signed-off-by: Maher Azzouzi <maherazz04@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-08-22tcp: clamp route advmss to TCP_MIN_MSSYong Wang
tcp_select_initial_window() assumes that callers never pass an MSS smaller than 1, but route-derived advmss values can violate that assumption. A too-small explicit RTAX_ADVMSS is one way to get there, but it is not the only one. The same divide-by-zero can also be reached through the "default advmss" path when RTAX_ADVMSS is left at 0 and the effective advmss is later driven down by route MTU and min_adv_mss. Introduce a tcp_dst_advmss() helper that clamps route advmss to TCP_MIN_MSS before TCP consumes it, and use it in the TCP paths that derive advmss from dst metrics. This keeps the effective MSS from dropping to zero before tcp_select_initial_window() rounds the receive window. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Signed-off-by: Yong Wang <edragain@163.com> Signed-off-by: Ren Wei <weir@nebusec.ai> Link: https://patch.msgid.link/251eaf8277fa7c66364c9815c5da01662d269181.1787074852.git.edragain@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-22ipip: fix skb leak in collect_md mode when metadata_dst allocation failsAnton Danilov
In collect_md mode ipip_tunnel_rcv() returns 0 without freeing the skb when ip_tun_rx_dst() fails to allocate the metadata_dst. ipip_rcv() and mplsip_rcv() are registered as xfrm_tunnel handlers, so tunnel4_rcv() and tunnelmpls4_rcv() read the zero return as "the packet has been consumed" and do not free it either. The skb is leaked. The other tunnel drivers all dispose of the packet at this point: ip6_tunnel.c jumps to its drop label, ip_gre.c and ip6_gre.c return PACKET_REJECT, which makes gre_rcv() free the skb. Only ipip returns 0. Jump to the existing drop label instead. It frees the skb and still returns 0, so the packet keeps being reported as consumed, which is what we want here: the outer header has already been pulled, and neither the remaining handlers nor an ICMP unreachable have any use for it. Triggering this needs an ipip or mplsip tunnel in collect_md mode and an atomic allocation failure, which is why it has gone unnoticed. Fixes: cfc7381b3002 ("ip_tunnel: add collect_md mode to IPIP tunnel") Cc: stable@vger.kernel.org Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260819104338.432631-2-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20net: tcp: block mixing readable and unreadable fragsMina Almasry
Protect tcp_sendmsg_locked() from mistakenly mixing readable and unreadable page fragments in the same SKB. Check that the devmem binding matches the existing SKB's readability. If a mismatch is detected, avoid collapsing and create a new segment. Fixes: bd61848900bff ("net: devmem: Implement TX path") Suggested-by: Eric Dumazet <edumazet@google.com> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Bobby Eshleman <bobbyeshleman@gmail.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20260814191336.187243-2-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20inetpeer: randomize RB-tree node comparison using SipHashEric Dumazet
The inetpeer rate limiting system stores peer entries in a Red-Black tree keyed deterministically on the remote IP address. Because tree lookups walk the RB-tree using standard lexicographical comparisons (inetpeer_addr_cmp), an off-path adversary can predict the exact topology of the tree and the sequence of nodes traversed during lookups (the gc_stack candidate list). By combining deterministic tree traversal with aggressive garbage collection (triggered when tree size exceeds inet_peer_threshold), an attacker can selectively force the eviction of targeted inet_peer nodes. When an evicted node is subsequently re-created upon receiving a new packet, its rate-limiting token bucket (rate_tokens, rate_last) is reset to full capacity. This creates a side-channel primitive allowing off-path attackers to bypass IP-keyed ICMP rate limits and infer open UDP ports (similar to SAD DNS style attacks). Mitigate this by randomizing the RB-tree node comparison logic using SipHash with a secret key (inetpeer_hash_key) initialized via net_get_random_once(). Nodes are ordered in the tree by SipHash(addr, key) rather than raw IP addresses. Because the secret key is unknown to external entities, the tree layout and lookup traversal paths are unpredictable to off-path adversaries, breaking the deterministic eviction gadget. Cache the computed 64-bit SipHash (hash) in struct inet_peer and compute the target hash (dhash) once at the beginning of inet_getpeer() to avoid recomputing SipHash at every step of the RB-tree walk. Fixes: b145425f269a ("inetpeer: remove AVL implementation in favor of RB tree") Reported-by: Michael Blunt <michaelbblunt@gmail.com> Suggested-by: Michael Blunt <michaelbblunt@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260818151213.3953963-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20net/tcp-ao: fix use-after-free of current_key on reconnect to another peerHyunwoo Kim
tcp_inbound_ao_hash() is called before bh_lock_sock_nested() is taken, with only rcu_read_lock() held. On the fast path for established sockets, if the rnext_keyid sent by the peer differs from current_key->sndid, the key the peer asked for is looked up and stored in current_key. The lookup is inside the RCU read side, but current_key outlives it. When the socket is disconnected and connect() is called again for another peer, tcp_ao_connect_init() unlinks every key that does not match the new peer and frees it with call_rcu(). If current_key points at such a key, it is cleared to NULL. The fast path reads sk_state only once on entry, so a softirq that got into it while the socket was still established can update current_key after that loop has already run. The update is inside the RCU read side, so it comes before the call_rcu() callback, and once the callback frees the key, current_key is left pointing at freed memory. The next transmission picks that pointer up in tcp_get_current_key(). tcp_ao_transmit_skb() then reads the traffic key from the freed object, which is the use-after-free. Wait for one grace period before unlinking, and only if a key is going to be removed. By the time tcp_connect() runs the socket is already in TCP_SYN_SENT, and TCP_AO_ESTABLISHED does not contain TCPF_SYN_SENT, so a softirq entering after the wait cannot reach the fast path, and the ones already in it have finished. The existing NULL handling in the loop is then enough. Fixes: 0a3a809089eb ("net/tcp: Verify inbound TCP-AO signed segments") Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/aoIriv3pHDgII2YR@v4bel Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20net: advertise TCP MSS from the configured MTU, not the learned PMTUJiayuan Chen
The MSS a host puts in its SYN tells the peer how big a segment it may send us. Right now we can shrink it with a PMTU we learned on our own send path, which is the wrong direction entirely. On asymmetric paths this bites - think DSR load balancers, where the request side goes through a smaller-MTU overlay. We learn a small PMTU going out, then advertise a small MSS, and the peer stays capped for the whole connection even though its path back to us is wide. MSS only shows up in the SYN and never grows back. On symmetric paths we lose nothing by dropping it either: the peer runs its own PMTU discovery and usually already knows the real path MTU. So work out the advertised MSS from the configured route or device MTU and ignore the learned PMTU. Our send side is unchanged, still clamped by tcp_current_mss(). Add ip_dst_mtu_configured()/ip6_dst_mtu_configured() and use them from the two default_advmss() paths. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: 164a5e7ad531 ("ipv4: ipv4_default_advmss() should use route mtu") Cc: stable@vger.kernel.org Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260815070413.294559-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20Merge tag 'net-next-7.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "One of the 'small improvements all over the place' releases for us. It's hard to draw any direct comparisons because summer vacations disrupted our patch processing (and presumably - generation) quite a bit. Quick and dirty count suggests we (Paolo and I) merged a very similar number of net (632) and net-next (648) patches. This is not telling the full story either because 1/3 to 1/2 of the net-next patches also *seem* like AI-driven low priority fixes, cleanups and clarifications. We are completely overwhelmed, of course. The glimmer of hope is that we secured sufficient LLM budget and access (thank you Meta!) to run reviews with multiple frontier models on each patch. This eliminates some hallucinations. That said, in terms of review, the LLMs can only do so much. The sad truth is that our APIs (especially for rare events like PCIe errors, timeouts etc) have always been racy, and now LLMs don't let us ignore that. I expect our direction for the next release will be to tweak the reviews a little bit more, but start shifting focus to letting the LLMs take care of the busy work - managing patchwork, automating common process complaints, editing commit messages, and maybe applying patches which already got "reviewed-by" tags from people we trust... Core & protocols: - A few steps lowering rtnl_lock dependence: - per-netns netdev unregistration for select SW drivers (e.g. veth, ipvlan, tunnels) - rtnl_lock-less FIB rule changes (RTM_NEWRULE and RTM_DELRULE) - prepare software drivers and TC qdiscs for rtnl_lock-less GET - Support BIG TCP (>64kB TSO) in UDP tunnels (vxlan, geneve) - Support buffers larger than PAGE_SIZE in devmem zero-copy API - Improve MPTCP handling of extreme memory pressure handling, when out-of-order queue had to be pruned - Report the per-group user count via RTM_GETMULTICAST - Expose the route deletion reason in RTM_DELROUTE - Add a SO_RIGHTS_NOTRUNC option to UNIX sockets to enable more useful handling of LSM denials when receiving SCM_RIGHTS messages: instead of truncating the message at the first blocked fd, keep every fd slot and store the LSM errno in the blocked slot - IPv6 Segment Routing - support looking up the post-encap SID (address) in a different/specified routing table - Support PRP RedBox (interlink) creation - Support per-nexthop UDP dst port in VXLAN - Continue converting getsockopt callbacks in a number of protocols to iov_iter Ethernet: - Merge initial CXL support for AMD/Solarflare NICs (shared branch with the CXL tree) - New drivers: - ADIN1140 10BASE-T1S MACPHY - Initial skeleton of Intel iXD and ZTE Dinghai drivers - High-speed NICs: - AMD/Pensando: - support firmware flashing - Cisco (enic): - SR-IOV V2 admin channel and MBOX protocol - Huawei (hns3): - support for ethtool pfc_prevention_tout - nVidia/Mellanox: - support sharing bandwidth control across interfaces of the same device - Marvell (octeontx2-pf): - link RQ page pools to netdev for Netlink stats - Google vNIC: - XDP metadata support for DQ RDA - Microsoft vNIC: - support forcing full-page RX buffers - Other NICs: - Synopsys IP: - eic7700: support for eth1 - Microchip (lan743x): - support for RMII interface - Wangxun: - support for ethtool -G and -C for VFs - add Tx timeout and PCIe error handling - Intel (igb/igc): - RSS key get/set support - support for forcing link speed without auto-negotiation - Switches: - NXP (dpaa2): - support bonding/LAG offload - Mediatek: - mt7530: EN7528 support - initial support for MT7628 - Micrel (ksz8/9): - refactoring work to move towards library model - PTP support for KSZ8463 - nVidia/Mellanox: - support rtnl-lock-less ethtool callbacks - Realtek: - rtl8366rb: use generic RTL83xx code - support SGMII and HSGMII for RTL8367S - PHYs: - Airoha: - EcoNet EN7528 PHY support - DAPU Telecom - DAPU Telecom DAP8211R(I) Gigabit PHY support - Realtek: - support RTL8261C_CG - support RTL8261D Wireless: - nl80211: per-link statistics support for multi-link operation - mac80211: AQL/airtime-fairness support for multicast - Merge Peripheral Authentication Service (PAS) / TEE support for ath12k (shared branch with the firmware/qcom tree) - New drivers: - mm81x for Morse Micro Long-Range S1G devices - nxpwifi for NXP devices (mostly forked off from mwifiex) - Driver changes: - Broadcom (brcmfmac): - DPP support, some Cypress part update - MediaTek (mt76): - mt7928 support - mt7925 NAN support - mt7996 AP powersave improvements - Qualcomm (ath12k): - much kernel infrastructure integration work - AHB platform MultiPD support - Realtek (rt89): - LED support - RTL8922DE support - dual-BT coex for RTL8922D - Intel: - new FW version support Bluetooth: - HCI: add support for Shorter Connection Interval (SCI) feature - af_bluetooth: add minimal context analysis annotations - Driver changes: - Intel: - add Bluetooth SAR revision 2 support - add vendor_reset PCI sysfs for PLDR - Mediatek: - add USB IDs for MT7902 and MT7922 devices - Realtek: - add USB IDs for 8761CU and 8852BE devices - NXP: - add M.2 Bluetooth device support using pwrseq Misc: - DPLL support for manual/numerical oscillator control (NCO) (implement in zl3073x) - MCTP support for MCTP over USB v1.1 (DMTF DSP0283) - Power-over-Ethernet: support Realtek PSE controllers - Remove the IBM EHEA driver - Remove tulip/xircom_cb driver" * tag 'net-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1433 commits) net/mlx5e: do not HW-GRO coalesce small frames net: openvswitch: fix nf_connlabels leak in ovs_ct_init net: add missing ref_tracker_dir_exit() to alloc_netdev_mqs() net: openvswitch: fix flow mask use-after-free on flow deletion sctp: stop processing a packet once its association is deleted dpll: zl3073x: add PTP clock support dpll: zl3073x: add channel ToD, phase step and TIE operations dpll: zl3073x: scale poll interval proportionally to timeout ptp: vmclock: prevent read-only mappings from becoming writable ipv4: reject undersized MTUs in ip_do_fragment() bonding: initialize err for empty target lists net: dsa: initial support for MT7628 embedded switch net: dsa: initial MT7628 tagging driver net: phy: mediatek: add phy driver for MT7628 built-in Fast Ethernet PHYs dt-bindings: net: dsa: add MT7628 ESW net: pse-pd: realtek-pse-mcu: add UART transport net: pse-pd: realtek-pse-mcu: add I2C transport net: pse-pd: add Realtek PSE MCU core dt-bindings: net: pse-pd: add bindings for Realtek PSE MCU vsock: use sock_error() to consume sk_err after a failed connect ...