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2026-04-21net: move promiscuity handling into netdev_rx_mode_workStanislav Fomichev
Move unicast promiscuity tracking into netdev_rx_mode_work so it runs under netdev_ops_lock instead of under the addr_lock spinlock. This is required because __dev_set_promiscuity calls dev_change_rx_flags and __dev_notify_flags, both of which may need to sleep. Change ASSERT_RTNL() to netdev_ops_assert_locked() in __dev_set_promiscuity, netif_set_allmulti and __dev_change_flags since these are now called from the work queue under the ops lock. Link: https://lore.kernel.org/netdev/20260214033859.43857-1-jiayuan.chen@linux.dev/ Fixes: 78cd408356fe ("net: add missing instance lock to dev_set_promiscuity") Reported-by: syzbot+2b3391f44313b3983e91@syzkaller.appspotmail.com Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20260416185712.2155425-5-sdf@fomichev.me Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-21net: cache snapshot entries for ndo_set_rx_mode_asyncStanislav Fomichev
Add a per-device netdev_hw_addr_list cache (rx_mode_addr_cache) that allows __hw_addr_list_snapshot() and __hw_addr_list_reconcile() to reuse previously allocated entries instead of hitting GFP_ATOMIC on every snapshot cycle. snapshot pops entries from the cache when available, falling back to __hw_addr_create(). reconcile splices both snapshot lists back into the cache via __hw_addr_splice(). The cache is flushed in free_netdev(). Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20260416185712.2155425-4-sdf@fomichev.me Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-21net: introduce ndo_set_rx_mode_async and netdev_rx_mode_workStanislav Fomichev
Add ndo_set_rx_mode_async callback that drivers can implement instead of the legacy ndo_set_rx_mode. The legacy callback runs under the netif_addr_lock spinlock with BHs disabled, preventing drivers from sleeping. The async variant runs from a work queue with rtnl_lock and netdev_lock_ops held, in fully sleepable context. When __dev_set_rx_mode() sees ndo_set_rx_mode_async, it schedules netdev_rx_mode_work instead of calling the driver inline. The work function takes two snapshots of each address list (uc/mc) under the addr_lock, then drops the lock and calls the driver with the work copies. After the driver returns, it reconciles the snapshots back to the real lists under the lock. Add netif_rx_mode_sync() to opportunistically execute the pending workqueue update inline, so that rx mode changes are committed before returning to userspace: - dev_change_flags (SIOCSIFFLAGS / RTM_NEWLINK) - dev_set_promiscuity - dev_set_allmulti - dev_ifsioc SIOCADDMULTI / SIOCDELMULTI - do_setlink (RTM_SETLINK) Note that some deep hierarchies still do skip the lower updates via: - dev_uc_sync - dev_mc_sync If we do end up hitting user-visible issues, we can add more calls to netif_rx_mode_sync in specific places. But hopefully we should not, the actual user-visible lists are still synced, it's that just HW state that might be lagging. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20260416185712.2155425-3-sdf@fomichev.me Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-21net: add address list snapshot and reconciliation infrastructureStanislav Fomichev
Introduce __hw_addr_list_snapshot() and __hw_addr_list_reconcile() for use by the upcoming ndo_set_rx_mode_async callback. The async rx_mode path needs to snapshot the device's unicast and multicast address lists under the addr_lock, hand those snapshots to the driver (which may sleep), and then propagate any sync_cnt changes back to the real lists. Two identical snapshots are taken: a work copy for the driver to pass to __hw_addr_sync_dev() and a reference copy to compute deltas against. __hw_addr_list_reconcile() walks the reference snapshot comparing each entry against the work snapshot to determine what the driver synced or unsynced. It then applies those deltas to the real list, handling concurrent modifications: - If the real entry was concurrently removed but the driver synced it to hardware (delta > 0), re-insert a stale entry so the next work run properly unsyncs it from hardware. - If the entry still exists, apply the delta normally. An entry whose refcount drops to zero is removed. # dev_addr_test_snapshot_benchmark: 1024 addrs x 1000 snapshots: 89872802 ns total, 89872 ns/iter # dev_addr_test_snapshot_benchmark.speed: slow Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20260416185712.2155425-2-sdf@fomichev.me Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-21netfilter: nf_tables: add hook transactions for device deletionsPablo Neira Ayuso
Restore the flag that indicates that the hook is going away, ie. NFT_HOOK_REMOVE, but add a new transaction object to track deletion of hooks without altering the basechain/flowtable hook_list during the preparation phase. The existing approach that moves the hook from the basechain/flowtable hook_list to transaction hook_list breaks netlink dump path readers of this RCU-protected list. It should be possible use an array for nft_trans_hook to store the deleted hooks to compact the representation but I am not expecting many hook object, specially now that wildcard support for devices is in place. Note that the nft_trans_chain_hooks() list contains a list of struct nft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while this list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE. Note that new commands can be updated to use nft_trans_hook for consistency. This patch also adapts the event notification path to deal with the list of hook transactions. Fixes: 7d937b107108 ("netfilter: nf_tables: support for deleting devices in an existing netdev chain") Fixes: b6d9014a3335 ("netfilter: nf_tables: delete flowtable hooks via transaction list") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-21netfilter: nf_tables: join hook list via splice_list_rcu() in commit phasePablo Neira Ayuso
Publish new hooks in the list into the basechain/flowtable using splice_list_rcu() to ensure netlink dump list traversal via rcu is safe while concurrent ruleset update is going on. Fixes: 78d9f48f7f44 ("netfilter: nf_tables: add devices to existing flowtable") Fixes: b9703ed44ffb ("netfilter: nf_tables: support for adding new devices to an existing netdev chain") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-21netfilter: nf_tables: use list_del_rcu for netlink hooksFlorian Westphal
nft_netdev_unregister_hooks and __nft_unregister_flowtable_net_hooks need to use list_del_rcu(), this list can be walked by concurrent dumpers. Add a new helper and use it consistently. Fixes: f9a43007d3f7 ("netfilter: nf_tables: double hook unregistration in netns path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-21netfilter: arp_tables: fix IEEE1394 ARP payload parsingPablo Neira Ayuso
Weiming Shi says: "arp_packet_match() unconditionally parses the ARP payload assuming two hardware addresses are present (source and target). However, IPv4-over-IEEE1394 ARP (RFC 2734) omits the target hardware address field, and arp_hdr_len() already accounts for this by returning a shorter length for ARPHRD_IEEE1394 devices. As a result, on IEEE1394 interfaces arp_packet_match() advances past a nonexistent target hardware address and reads the wrong bytes for both the target device address comparison and the target IP address. This causes arptables rules to match against garbage data, leading to incorrect filtering decisions: packets that should be accepted may be dropped and vice versa. The ARP stack in net/ipv4/arp.c (arp_create and arp_process) already handles this correctly by skipping the target hardware address for ARPHRD_IEEE1394. Apply the same pattern to arp_packet_match()." Mangle the original patch to always return 0 (no match) in case user matches on the target hardware address which is never present in IEEE1394. Note that this returns 0 (no match) for either normal and inverse match because matching in the target hardware address in ARPHRD_IEEE1394 has never been supported by arptables. This is intentional, matching on the target hardware address should never evaluate true for ARPHRD_IEEE1394. Moreover, adjust arpt_mangle to drop the packet too as AI suggests: In arpt_mangle, the logic assumes a standard ARP layout. Because IEEE1394 (FireWire) omits the target hardware address, the linear pointer arithmetic miscalculates the offset for the target IP address. This causes mangling operations to write to the wrong location, leading to packet corruption. To ensure safety, this patch drops packets (NF_DROP) when mangling is requested for these fields on IEEE1394 devices, as the current implementation cannot correctly map the FireWire ARP payload. This omits both mangling target hardware and IP address. Even if IP address mangling should be possible in IEEE1394, this would require to adjust arpt_mangle offset calculation, which has never been supported. Based on patch from Weiming Shi <bestswngs@gmail.com>. Fixes: 6752c8db8e0c ("firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection.") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: nfnetlink_osf: fix potential NULL dereference in ttl checkFernando Fernandez Mancera
The nf_osf_ttl() function accessed skb->dev to perform a local interface address lookup without verifying that the device pointer was valid. Additionally, the implementation utilized an in_dev_for_each_ifa_rcu loop to match the packet source address against local interface addresses. It assumed that packets from the same subnet should not see a decrement on the initial TTL. A packet might appear it is from the same subnet but it actually isn't especially in modern environments with containers and virtual switching. Remove the device dereference and interface loop. Replace the logic with a switch statement that evaluates the TTL according to the ttl_check. Fixes: 11eeef41d5f6 ("netfilter: passive OS fingerprint xtables match") Reported-by: Kito Xu (veritas501) <hxzene@gmail.com> Closes: https://lore.kernel.org/netfilter-devel/20260414074556.2512750-1-hxzene@gmail.com/ Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: nfnetlink_osf: fix out-of-bounds read on option matchingFernando Fernandez Mancera
In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once and passed by reference to nf_osf_match_one() for each fingerprint checked. During TCP option parsing, nf_osf_match_one() advances the shared ctx->optp pointer. If a fingerprint perfectly matches, the function returns early without restoring ctx->optp to its initial state. If the user has configured NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint. However, because ctx->optp was not restored, the next call to nf_osf_match_one() starts parsing from the end of the options buffer. This causes subsequent matches to read garbage data and fail immediately, making it impossible to log more than one match or logging incorrect matches. Instead of using a shared ctx->optp pointer, pass the context as a constant pointer and use a local pointer (optp) for TCP option traversal. This makes nf_osf_match_one() strictly stateless from the caller's perspective, ensuring every fingerprint check starts at the correct option offset. Fixes: 1a6a0951fc00 ("netfilter: nfnetlink_osf: add missing fmatch check") Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20ipvs: fix MTU check for GSO packets in tunnel modeYingnan Zhang
Currently, IPVS skips MTU checks for GSO packets by excluding them with the !skb_is_gso(skb) condition. This creates problems when IPVS tunnel mode encapsulates GSO packets with IPIP headers. The issue manifests in two ways: 1. MTU violation after encapsulation: When a GSO packet passes through IPVS tunnel mode, the original MTU check is bypassed. After adding the IPIP tunnel header, the packet size may exceed the outgoing interface MTU, leading to unexpected fragmentation at the IP layer. 2. Fragmentation with problematic IP IDs: When net.ipv4.vs.pmtu_disc=1 and a GSO packet with multiple segments is fragmented after encapsulation, each segment gets a sequentially incremented IP ID (0, 1, 2, ...). This happens because: a) The GSO packet bypasses MTU check and gets encapsulated b) At __ip_finish_output, the oversized GSO packet is split into separate SKBs (one per segment), with IP IDs incrementing c) Each SKB is then fragmented again based on the actual MTU This sequential IP ID allocation differs from the expected behavior and can cause issues with fragment reassembly and packet tracking. Fix this by properly validating GSO packets using skb_gso_validate_network_len(). This function correctly validates whether the GSO segments will fit within the MTU after segmentation. If validation fails, send an ICMP Fragmentation Needed message to enable proper PMTU discovery. Fixes: 4cdd34084d53 ("netfilter: nf_conntrack_ipv6: improve fragmentation handling") Signed-off-by: Yingnan Zhang <342144303@qq.com> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: nat: use kfree_rcu to release opsPablo Neira Ayuso
Florian Westphal says: "Historically this is not an issue, even for normal base hooks: the data path doesn't use the original nf_hook_ops that are used to register the callbacks. However, in v5.14 I added the ability to dump the active netfilter hooks from userspace. This code will peek back into the nf_hook_ops that are available at the tail of the pointer-array blob used by the datapath. The nat hooks are special, because they are called indirectly from the central nat dispatcher hook. They are currently invisible to the nfnl hook dump subsystem though. But once that changes the nat ops structures have to be deferred too." Update nf_nat_register_fn() to deal with partial exposition of the hooks from error path which can be also an issue for nfnetlink_hook. Fixes: e2cf17d3774c ("netfilter: add new hook nfnl subsystem") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: xtables: restrict several matches to inet familyPablo Neira Ayuso
This is a partial revert of: commit ab4f21e6fb1c ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions") to allow ipv4 and ipv6 only. - xt_mac - xt_owner - xt_physdev These extensions are not used by ebtables in userspace. Moreover, xt_realm is only for ipv4, since dst->tclassid is ipv4 specific. Fixes: ab4f21e6fb1c ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions") Reported-by: "Kito Xu (veritas501)" <hxzene@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: conntrack: remove sprintf usageFlorian Westphal
Replace it with scnprintf, the buffer sizes are expected to be large enough to hold the result, no need for snprintf+overflow check. Increase buffer size in mangle_content_len() while at it. BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270 Write of size 1 at addr [..] vsnprintf+0xea5/0x1270 sprintf+0xb1/0xe0 mangle_content_len+0x1ac/0x280 nf_nat_sdp_session+0x1cc/0x240 process_sdp+0x8f8/0xb80 process_invite_request+0x108/0x2b0 process_sip_msg+0x5da/0xf50 sip_help_tcp+0x45e/0x780 nf_confirm+0x34d/0x990 [..] Fixes: 9fafcd7b2032 ("[NETFILTER]: nf_conntrack/nf_nat: add SIP helper port") Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: nfnetlink_osf: fix divide-by-zero in OSF_WSS_MODULOXiang Mei
nf_osf_match_one() computes ctx->window % f->wss.val in the OSF_WSS_MODULO branch with no guard for f->wss.val == 0. A CAP_NET_ADMIN user can add such a fingerprint via nfnetlink; a subsequent matching TCP SYN divides by zero and panics the kernel. Reject the bogus fingerprint in nfnl_osf_add_callback() above the per-option for-loop. f->wss is per-fingerprint, not per-option, so the check must run regardless of f->opt_num (including 0). Also reject wss.wc >= OSF_WSS_MAX; nf_osf_match_one() already treats that as "should not happen". Crash: Oops: divide error: 0000 [#1] SMP KASAN NOPTI RIP: 0010:nf_osf_match_one (net/netfilter/nfnetlink_osf.c:98) Call Trace: <IRQ> nf_osf_match (net/netfilter/nfnetlink_osf.c:220) xt_osf_match_packet (net/netfilter/xt_osf.c:32) ipt_do_table (net/ipv4/netfilter/ip_tables.c:348) nf_hook_slow (net/netfilter/core.c:622) ip_local_deliver (net/ipv4/ip_input.c:265) ip_rcv (include/linux/skbuff.h:1162) __netif_receive_skb_one_core (net/core/dev.c:6181) process_backlog (net/core/dev.c:6642) __napi_poll (net/core/dev.c:7710) net_rx_action (net/core/dev.c:7945) handle_softirqs (kernel/softirq.c:622) Fixes: 11eeef41d5f6 ("netfilter: passive OS fingerprint xtables match") Reported-by: Weiming Shi <bestswngs@gmail.com> Suggested-by: Florian Westphal <fw@strlen.de> Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20netfilter: nft_osf: restrict it to ipv4Pablo Neira Ayuso
This expression only supports for ipv4, restrict it. Fixes: b96af92d6eaf ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf") Acked-by: Florian Westphal <fw@strlen.de> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-20net: mctp: fix don't require received header reserved bits to be zeroYuan Zhaoming
From the MCTP Base specification (DSP0236 v1.2.1), the first byte of the MCTP header contains a 4 bit reserved field, and 4 bit version. On our current receive path, we require those 4 reserved bits to be zero, but the 9500-8i card is non-conformant, and may set these reserved bits. DSP0236 states that the reserved bits must be written as zero, and ignored when read. While the device might not conform to the former, we should accept these message to conform to the latter. Relax our check on the MCTP version byte to allow non-zero bits in the reserved field. Fixes: 889b7da23abf ("mctp: Add initial routing framework") Signed-off-by: Yuan Zhaoming <yuanzm2@lenovo.com> Cc: stable@vger.kernel.org Acked-by: Jeremy Kerr <jk@codeconstruct.com.au> Link: https://patch.msgid.link/20260417141340.5306-1-yuanzhaoming901030@126.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-20hv_sock: Report EOF instead of -EIO for FINDexuan Cui
Commit f0c5827d07cb unluckily causes a regression for the FIN packet, and the final read syscall gets an error rather than 0. Ideally, we would want to fix hvs_channel_readable_payload() so that it could return 0 in the FIN scenario, but it's not good for the hv_sock driver to use the VMBus ringbuffer's cached priv_read_index, which is internal data in the VMBus driver. Fix the regression in hv_sock by returning 0 rather than -EIO. Fixes: f0c5827d07cb ("hv_sock: Return the readable bytes in hvs_stream_has_data()") Cc: stable@vger.kernel.org Reported-by: Ben Hillis <Ben.Hillis@microsoft.com> Reported-by: Mitchell Levy <levymitchell0@gmail.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://patch.msgid.link/20260416191433.840637-1-decui@microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-20openvswitch: cap upcall PID array size and pre-size vport repliesWeiming Shi
The vport netlink reply helpers allocate a fixed-size skb with nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID array via ovs_vport_get_upcall_portids(). Since ovs_vport_set_upcall_portids() accepts any non-zero multiple of sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID array large enough to overflow the reply buffer, causing nla_put() to fail with -EMSGSIZE and hitting BUG_ON(err < 0). On systems with unprivileged user namespaces enabled (e.g., Ubuntu default), this is reachable via unshare -Urn since OVS vport mutation operations use GENL_UNS_ADMIN_PERM. kernel BUG at net/openvswitch/datapath.c:2414! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1 RIP: 0010:ovs_vport_cmd_set+0x34c/0x400 Call Trace: <TASK> genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116) genl_rcv_msg (net/netlink/genetlink.c:1194) netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/genetlink.c:1219) netlink_unicast (net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sys_sendto (net/socket.c:2206) __x64_sys_sendto (net/socket.c:2209) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> Kernel panic - not syncing: Fatal exception Reject attempts to set more PIDs than nr_cpu_ids in ovs_vport_set_upcall_portids(), and pre-compute the worst-case reply size in ovs_vport_cmd_msg_size() based on that bound, similar to the existing ovs_dp_cmd_msg_size(). nr_cpu_ids matches the cap already used by the per-CPU dispatch configuration on the datapath side (ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the two sides stay consistent. Fixes: 5cd667b0a456 ("openvswitch: Allow each vport to have an array of 'port_id's.") Reported-by: Xiang Mei <xmei5@asu.edu> Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260416024653.153456-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-20flow_dissector: do not dissect PPPoE PFC framesQingfang Deng
RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT RECOMMENDED for PPPoE. In practice, pppd does not support negotiating PFC for PPPoE sessions, and the flow dissector driver has assumed an uncompressed frame until the blamed commit. During the review process of that commit [1], support for PFC is suggested. However, having a compressed (1-byte) protocol field means the subsequent PPP payload is shifted by one byte, causing 4-byte misalignment for the network header and an unaligned access exception on some architectures. The exception can be reproduced by sending a PPPoE PFC frame to an ethernet interface of a MIPS board, with RPS enabled, even if no PPPoE session is active on that interface: $ 0 : 00000000 80c40000 00000000 85144817 $ 4 : 00000008 00000100 80a75758 81dc9bb8 $ 8 : 00000010 8087ae2c 0000003d 00000000 $12 : 000000e0 00000039 00000000 00000000 $16 : 85043240 80a75758 81dc9bb8 00006488 $20 : 0000002f 00000007 85144810 80a70000 $24 : 81d1bda0 00000000 $28 : 81dc8000 81dc9aa8 00000000 805ead08 Hi : 00009d51 Lo : 2163358a epc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50 ra : 805ead08 __skb_get_hash_net+0x74/0x12c Status: 11000403 KERNEL EXL IE Cause : 40800010 (ExcCode 04) BadVA : 85144817 PrId : 0001992f (MIPS 1004Kc) Call Trace: [<805e91f0>] __skb_flow_dissect+0x1b0/0x1b50 [<805ead08>] __skb_get_hash_net+0x74/0x12c [<805ef330>] get_rps_cpu+0x1b8/0x3fc [<805fca70>] netif_receive_skb_list_internal+0x324/0x364 [<805fd120>] napi_complete_done+0x68/0x2a4 [<8058de5c>] mtk_napi_rx+0x228/0xfec [<805fd398>] __napi_poll+0x3c/0x1c4 [<805fd754>] napi_threaded_poll_loop+0x234/0x29c [<805fd848>] napi_threaded_poll+0x8c/0xb0 [<80053544>] kthread+0x104/0x12c [<80002bd8>] ret_from_kernel_thread+0x14/0x1c Code: 02d51821 1060045b 00000000 <8c640000> 3084000f 2c820005 144001a2 00042080 8e220000 To reduce the attack surface and maintain performance, do not process PPPoE PFC frames. [1] https://lore.kernel.org/r/20220630231016.GA392@debian.home Fixes: 46126db9c861 ("flow_dissector: Add PPPoE dissectors") Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/20260415022456.141758-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-20Merge tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds
Pull nfsd updates from Chuck Lever: - filehandle signing to defend against filehandle-guessing attacks (Benjamin Coddington) The server now appends a SipHash-2-4 MAC to each filehandle when the new "sign_fh" export option is enabled. NFSD then verifies filehandles received from clients against the expected MAC; mismatches return NFS error STALE - convert the entire NLMv4 server-side XDR layer from hand-written C to xdrgen-generated code, spanning roughly thirty patches (Chuck Lever) XDR functions are generally boilerplate code and are easy to get wrong. The goals of this conversion are improved memory safety, lower maintenance burden, and groundwork for eventual Rust code generation for these functions. - improve pNFS block/SCSI layout robustness with two related changes (Dai Ngo) SCSI persistent reservation fencing is now tracked per client and per device via an xarray, to avoid both redundant preempt operations on devices already fenced and a potential NFSD deadlock when all nfsd threads are waiting for a layout return. - scalability and infrastructure improvements Sincere thanks to all contributors, reviewers, testers, and bug reporters who participated in the v7.1 NFSD development cycle. * tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (83 commits) NFSD: Docs: clean up pnfs server timeout docs nfsd: fix comment typo in nfsxdr nfsd: fix comment typo in nfs3xdr NFSD: convert callback RPC program to per-net namespace NFSD: use per-operation statidx for callback procedures svcrdma: Use contiguous pages for RDMA Read sink buffers SUNRPC: Add svc_rqst_page_release() helper SUNRPC: xdr.h: fix all kernel-doc warnings svcrdma: Factor out WR chain linking into helper svcrdma: Add Write chunk WRs to the RPC's Send WR chain svcrdma: Clean up use of rdma->sc_pd->device svcrdma: Clean up use of rdma->sc_pd->device in Receive paths svcrdma: Add fair queuing for Send Queue access SUNRPC: Optimize rq_respages allocation in svc_alloc_arg SUNRPC: Track consumed rq_pages entries svcrdma: preserve rq_next_page in svc_rdma_save_io_pages SUNRPC: Handle NULL entries in svc_rqst_release_pages SUNRPC: Allocate a separate Reply page array SUNRPC: Tighten bounds checking in svc_rqst_replace_page NFSD: Sign filehandles ...
2026-04-20xfrm: ah: account for ESN high bits in async callbacksMichael Bommarito
AH allocates its temporary auth/ICV layout differently when ESN is enabled: the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent. With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift: ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24 ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36 Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot. Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine. Fixes: d4d573d0334d ("{IPv4,xfrm} Add ESN support for AH egress part") Fixes: d8b2a8600b0e ("{IPv4,xfrm} Add ESN support for AH ingress part") Fixes: 26dd70c3fad3 ("{IPv6,xfrm} Add ESN support for AH egress part") Fixes: 8d6da6f32557 ("{IPv6,xfrm} Add ESN support for AH ingress part") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5-4 Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-04-18sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunksMichael Bommarito
sctp_getsockopt_peer_auth_chunks() checks that the caller's optval buffer is large enough for the peer AUTH chunk list with if (len < num_chunks) return -EINVAL; but then writes num_chunks bytes to p->gauth_chunks, which lives at offset offsetof(struct sctp_authchunks, gauth_chunks) == 8 inside optval. The check is missing the sizeof(struct sctp_authchunks) = 8-byte header. When the caller supplies len == num_chunks (for any num_chunks > 0) the test passes but copy_to_user() writes sizeof(struct sctp_authchunks) = 8 bytes past the declared buffer. The sibling function sctp_getsockopt_local_auth_chunks() at the next line already has the correct check: if (len < sizeof(struct sctp_authchunks) + num_chunks) return -EINVAL; Align the peer variant with its sibling. Reproducer confirms on v7.0-13-generic: an unprivileged userspace caller that opens a loopback SCTP association with AUTH enabled, queries num_chunks with a short optval, then issues the real getsockopt with len == num_chunks and sentinel bytes painted past the buffer observes those sentinel bytes overwritten with the peer's AUTH chunk type. The bytes written are under the peer's control but land in the caller's own userspace; this is not a kernel memory corruption, but it is a kernel-side contract violation that can silently corrupt adjacent userspace data. Fixes: 65b07e5d0d09 ("[SCTP]: API updates to suport SCTP-AUTH extensions.") Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20260416031903.1447072-1-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18af_unix: Drop all SCM attributes for SOCKMAP.Kuniyuki Iwashima
SOCKMAP can hide inflight fd from AF_UNIX GC. When a socket in SOCKMAP receives skb with inflight fd, sk_psock_verdict_data_ready() looks up the mapped socket and enqueue skb to its psock->ingress_skb. Since neither the old nor the new GC can inspect the psock queue, the hidden skb leaks the inflight sockets. Note that this cannot be detected via kmemleak because inflight sockets are linked to a global list. In addition, SOCKMAP redirect breaks the Tarjan-based GC's assumption that unix_edge.successor is always alive, which is no longer true once skb is redirected, resulting in use-after-free below. [0] Moreover, SOCKMAP does not call scm_stat_del() properly, so unix_show_fdinfo() could report an incorrect fd count. sk_msg_recvmsg() does not support any SCM attributes in the first place. Let's drop all SCM attributes before passing skb to the SOCKMAP layer. [0]: BUG: KASAN: slab-use-after-free in unix_del_edges (net/unix/garbage.c:118 net/unix/garbage.c:181 net/unix/garbage.c:251) Read of size 8 at addr ffff888125362670 by task kworker/56:1/496 CPU: 56 UID: 0 PID: 496 Comm: kworker/56:1 Not tainted 7.0.0-rc7-00263-gb9d8b856689d #3 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 Workqueue: events sk_psock_backlog Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:379) kasan_report (mm/kasan/report.c:597) unix_del_edges (net/unix/garbage.c:118 net/unix/garbage.c:181 net/unix/garbage.c:251) unix_destroy_fpl (net/unix/garbage.c:317) unix_destruct_scm (./include/net/scm.h:80 ./include/net/scm.h:86 net/unix/af_unix.c:1976) sk_psock_backlog (./include/linux/skbuff.h:?) process_scheduled_works (kernel/workqueue.c:?) worker_thread (kernel/workqueue.c:?) kthread (kernel/kthread.c:438) ret_from_fork (arch/x86/kernel/process.c:164) ret_from_fork_asm (arch/x86/entry/entry_64.S:258) </TASK> Allocated by task 955: kasan_save_track (mm/kasan/common.c:58 mm/kasan/common.c:78) __kasan_slab_alloc (mm/kasan/common.c:369) kmem_cache_alloc_noprof (mm/slub.c:4539) sk_prot_alloc (net/core/sock.c:2240) sk_alloc (net/core/sock.c:2301) unix_create1 (net/unix/af_unix.c:1099) unix_create (net/unix/af_unix.c:1169) __sock_create (net/socket.c:1606) __sys_socketpair (net/socket.c:1811) __x64_sys_socketpair (net/socket.c:1863 net/socket.c:1860 net/socket.c:1860) do_syscall_64 (arch/x86/entry/syscall_64.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 496: kasan_save_track (mm/kasan/common.c:58 mm/kasan/common.c:78) kasan_save_free_info (mm/kasan/generic.c:587) __kasan_slab_free (mm/kasan/common.c:287) kmem_cache_free (mm/slub.c:6165) __sk_destruct (net/core/sock.c:2282 net/core/sock.c:2384) sk_psock_destroy (./include/net/sock.h:?) process_scheduled_works (kernel/workqueue.c:?) worker_thread (kernel/workqueue.c:?) kthread (kernel/kthread.c:438) ret_from_fork (arch/x86/kernel/process.c:164) ret_from_fork_asm (arch/x86/entry/entry_64.S:258) Fixes: c63829182c37 ("af_unix: Implement ->psock_update_sk_prot()") Fixes: 77462de14a43 ("af_unix: Add read_sock for stream socket types") Reported-by: Xingyu Jin <xingyuj@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260415184830.3988432-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18ipv6: fix possible UAF in icmpv6_rcv()Eric Dumazet
Caching saddr and daddr before pskb_pull() is problematic since skb->head can change. Remove these temporary variables: - We only access &ipv6_hdr(skb)->saddr and &ipv6_hdr(skb)->daddr when net_dbg_ratelimited() is called in the slow path. - Avoid potential future misuse after pskb_pull() call. Fixes: 4b3418fba0fe ("ipv6: icmp: include addresses in debug messages") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Joe Damato <joe@dama.to> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260416103505.2380753-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->plb_rehashEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 29c1c44646ae ("tcp: add u32 counter in tcp_sock and an SNMP counter for PLB") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-15-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around (tp->write_seq - tp->snd_nxt)Eric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() annotations to keep KCSAN happy. WRITE_ONCE() annotations are already present. Fixes: e08ab0b377a1 ("tcp: add bytes not sent to SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-14-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->timeout_rehashEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 32efcc06d2a1 ("tcp: export count for rehash attempts") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-13-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->srtt_usEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: e8bd8fca6773 ("tcp: add SRTT to SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-12-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->reord_seenEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 7ec65372ca53 ("tcp: add stat of data packet reordering events") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-11-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->dsack_dupsEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 7e10b6554ff2 ("tcp: add dsack blocks received stats") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-10-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->bytes_retransEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: fb31c9b9f6c8 ("tcp: add data bytes retransmitted stats") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->bytes_sentEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: ba113c3aa79a ("tcp: add data bytes sent stats") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: add data-race annotations for TCP_NLA_SNDQ_SIZEEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 87ecc95d81d9 ("tcp: add send queue size stat in SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->delivered and tp->delivered_ceEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: feb5f2ec6464 ("tcp: export packets delivery info") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races around tp->snd_ssthreshEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 7156d194a077 ("tcp: add snd_ssthresh stat in SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: add data-races annotations around tp->reordering, tp->snd_cwndEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE(), WRITE_ONCE() data_race() annotations to keep KCSAN happy. Fixes: bb7c19f96012 ("tcp: add related fields into SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: add data-race annotations around tp->data_segs_out and tp->total_retransEric Dumazet
tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 7e98102f4897 ("tcp: record pkts sent and retransmistted") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-18tcp: annotate data-races in tcp_get_info_chrono_stats()Eric Dumazet
tcp_get_timestamping_opt_stats() does not own the socket lock, this is intentional. It calls tcp_get_info_chrono_stats() while other threads could change chrono fields in tcp_chrono_set(). I do not think we need coherent TCP socket state snapshot in tcp_get_timestamping_opt_stats(), I chose to only add annotations to keep KCSAN happy. Fixes: 1c885808e456 ("tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260416200319.3608680-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-17Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Alexei Starovoitov: "Most of the diff stat comes from Xu Kuohai's fix to emit ENDBR/BTI, since all JITs had to be touched to move constant blinding out and pass bpf_verifier_env in. - Fix use-after-free in arena_vm_close on fork (Alexei Starovoitov) - Dissociate struct_ops program with map if map_update fails (Amery Hung) - Fix out-of-range and off-by-one bugs in arm64 JIT (Daniel Borkmann) - Fix precedence bug in convert_bpf_ld_abs alignment check (Daniel Borkmann) - Fix arg tracking for imprecise/multi-offset in BPF_ST/STX insns (Eduard Zingerman) - Copy token from main to subprogs to fix missing kallsyms (Eduard Zingerman) - Prevent double close and leak of btf objects in libbpf (Jiri Olsa) - Fix af_unix null-ptr-deref in sockmap (Michal Luczaj) - Fix NULL deref in map_kptr_match_type for scalar regs (Mykyta Yatsenko) - Avoid unnecessary IPIs. Remove redundant bpf_flush_icache() in arm64 and riscv JITs (Puranjay Mohan) - Fix out of bounds access. Validate node_id in arena_alloc_pages() (Puranjay Mohan) - Reject BPF-to-BPF calls and callbacks in arm32 JIT (Puranjay Mohan) - Refactor all JITs to pass bpf_verifier_env to emit ENDBR/BTI for indirect jump targets on x86-64, arm64 JITs (Xu Kuohai) - Allow UTF-8 literals in bpf_bprintf_prepare() (Yihan Ding)" * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (32 commits) bpf, arm32: Reject BPF-to-BPF calls and callbacks in the JIT bpf: Dissociate struct_ops program with map if map_update fails bpf: Validate node_id in arena_alloc_pages() libbpf: Prevent double close and leak of btf objects selftests/bpf: cover UTF-8 trace_printk output bpf: allow UTF-8 literals in bpf_bprintf_prepare() selftests/bpf: Reject scalar store into kptr slot bpf: Fix NULL deref in map_kptr_match_type for scalar regs bpf: Fix precedence bug in convert_bpf_ld_abs alignment check bpf, arm64: Emit BTI for indirect jump target bpf, x86: Emit ENDBR for indirect jump targets bpf: Add helper to detect indirect jump targets bpf: Pass bpf_verifier_env to JIT bpf: Move constants blinding out of arch-specific JITs bpf, sockmap: Take state lock for af_unix iter bpf, sockmap: Fix af_unix null-ptr-deref in proto update selftests/bpf: Extend bpf_iter_unix to attempt deadlocking bpf, sockmap: Fix af_unix iter deadlock bpf, sockmap: Annotate af_unix sock:: Sk_state data-races selftests/bpf: verify kallsyms entries for token-loaded subprograms ...
2026-04-17ipv6: xfrm6: release dst on error in xfrm6_rcv_encap()Yilin Zhu
xfrm6_rcv_encap() performs an IPv6 route lookup when the skb does not already have a dst attached. ip6_route_input_lookup() returns a referenced dst entry even when the lookup resolves to an error route. If dst->error is set, xfrm6_rcv_encap() drops the skb without attaching the dst to the skb and without releasing the reference returned by the lookup. Repeated packets hitting this path therefore leak dst entries. Release the dst before jumping to the drop path. Fixes: 0146dca70b87 ("xfrm: add support for UDPv6 encapsulation of ESP") Cc: stable@kernel.org Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Co-developed-by: Yuan Tan <yuantan098@gmail.com> Signed-off-by: Yuan Tan <yuantan098@gmail.com> Suggested-by: Xin Liu <bird@lzu.edu.cn> Tested-by: Ruide Cao <caoruide123@gmail.com> Signed-off-by: Yilin Zhu <zylzyl2333@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-04-16vsock/virtio: fix MSG_PEEK ignoring skb offset when calculating bytes to copyLuigi Leonardi
`virtio_transport_stream_do_peek()` does not account for the skb offset when computing the number of bytes to copy. This means that, after a partial recv() that advances the offset, a peek requesting more bytes than are available in the sk_buff causes `skb_copy_datagram_iter()` to go past the valid payload, resulting in a -EFAULT. The dequeue path already handles this correctly. Apply the same logic to the peek path. Fixes: 0df7cd3c13e4 ("vsock/virtio/vhost: read data from non-linear skb") Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com> Signed-off-by: Luigi Leonardi <leonardi@redhat.com> Link: https://patch.msgid.link/20260415-fix_peek-v4-1-8207e872759e@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-16net: dsa: remove redundant netdev_lock_ops() from conduit ethtool opsStanislav Fomichev
DSA replaces the conduit (master) device's ethtool_ops with its own wrappers that aggregate stats from both the conduit and DSA switch ports. Taking the lock again inside the DSA wrappers causes a deadlock. Stumbled upon this when booting qemu with fbnic and CONFIG_NET_DSA_LOOP=y (which looks like some kind of testing device that auto-populates the ports of eth0). `ethtool -i` is enough to deadlock. This means we have basically zero coverage for DSA stuff with real ops locked devs. Remove the redundant netdev_lock_ops()/netdev_unlock_ops() calls from the DSA conduit ethtool wrappers. Fixes: 2bcf4772e45a ("net: ethtool: try to protect all callback with netdev instance lock") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://patch.msgid.link/20260414231035.1917035-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-16net/sched: taprio: fix use-after-free in advance_sched() on schedule switchVinicius Costa Gomes
In advance_sched(), when should_change_schedules() returns true, switch_schedules() is called to promote the admin schedule to oper. switch_schedules() queues the old oper schedule for RCU freeing via call_rcu(), but 'next' still points into an entry of the old oper schedule. The subsequent 'next->end_time = end_time' and rcu_assign_pointer(q->current_entry, next) are use-after-free. Fix this by selecting 'next' from the new oper schedule immediately after switch_schedules(), and using its pre-calculated end_time. setup_first_end_time() sets the first entry's end_time to base_time + interval when the schedule is installed, so the value is already correct. The deleted 'end_time = sched_base_time(admin)' assignment was also harmful independently: it would overwrite the new first entry's pre-calculated end_time with just base_time. Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule") Reported-by: Junxi Qian <qjx1298677004@gmail.com> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-16bpf: Fix precedence bug in convert_bpf_ld_abs alignment checkDaniel Borkmann
Fix an operator precedence issue in convert_bpf_ld_abs() where the expression offset + ip_align % size evaluates as offset + (ip_align % size) due to % having higher precedence than +. That latter evaluation does not make any sense. The intended check is (offset + ip_align) % size == 0 to verify that the packet load offset is properly aligned for direct access. With NET_IP_ALIGN == 2, the bug causes the inline fast-path for direct packet loads to almost never be taken on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS platforms. This forces nearly all cBPF BPF_LD_ABS packet loads through the bpf_skb_load_helper slow path on the affected archs. Fixes: e0cea7ce988c ("bpf: implement ld_abs/ld_ind in native bpf") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20260416122719.661033-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-04-16vsock/virtio: fix accept queue count leak on transport mismatchDudu Lu
virtio_transport_recv_listen() calls sk_acceptq_added() before vsock_assign_transport(). If vsock_assign_transport() fails or selects a different transport, the error path returns without calling sk_acceptq_removed(), permanently incrementing sk_ack_backlog. After approximately backlog+1 such failures, sk_acceptq_is_full() returns true, causing the listener to reject all new connections. Fix by moving sk_acceptq_added() to after the transport validation, matching the pattern used by vmci_transport and hyperv_transport. Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Signed-off-by: Dudu Lu <phx0fer@gmail.com> Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com> Reviewed-by: Luigi Leonardi <leonardi@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260413131409.19022-1-phx0fer@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-16nexthop: fix IPv6 route referencing IPv4 nexthopJiayuan Chen
syzbot reported a panic [1] [2]. When an IPv6 nexthop is replaced with an IPv4 nexthop, the has_v4 flag of all groups containing this nexthop is not updated. This is because nh_group_v4_update is only called when replacing AF_INET to AF_INET6, but the reverse direction (AF_INET6 to AF_INET) is missed. This allows a stale has_v4=false to bypass fib6_check_nexthop, causing IPv6 routes to be attached to groups that effectively contain only AF_INET members. Subsequent route lookups then call nexthop_fib6_nh() which returns NULL for the AF_INET member, leading to a NULL pointer dereference. Fix by calling nh_group_v4_update whenever the family changes, not just AF_INET to AF_INET6. Reproducer: # AF_INET6 blackhole ip -6 nexthop add id 1 blackhole # group with has_v4=false ip nexthop add id 100 group 1 # replace with AF_INET (no -6), has_v4 stays false ip nexthop replace id 1 blackhole # pass stale has_v4 check ip -6 route add 2001:db8::/64 nhid 100 # panic ping -6 2001:db8::1 [1] https://syzkaller.appspot.com/bug?id=e17283eb2f8dcf3dd9b47fe6f67a95f71faadad0 [2] https://syzkaller.appspot.com/bug?id=8699b6ae54c9f35837d925686208402949e12ef3 Fixes: 7bf4796dd099 ("nexthops: add support for replace") Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20260413114522.147784-1-jiayuan.chen@linux.dev Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-16net/sched: sch_cake: fix NAT destination port not being updated in ↵Dudu Lu
cake_update_flowkeys cake_update_flowkeys() is supposed to update the flow dissector keys with the NAT-translated addresses and ports from conntrack, so that CAKE's per-flow fairness correctly identifies post-NAT flows as belonging to the same connection. For the source port, this works correctly: keys->ports.src = port; But for the destination port, the assignment is reversed: port = keys->ports.dst; This means the NAT destination port is never updated in the flow keys. As a result, when multiple connections are NATed to the same destination, CAKE treats them as separate flows because the original (pre-NAT) destination ports differ. This breaks CAKE's NAT-aware flow isolation when using the "nat" mode. The bug was introduced in commit b0c19ed6088a ("sch_cake: Take advantage of skb->hash where appropriate") which refactored the original direct assignment into a compare-and-conditionally-update pattern, but wrote the destination port update backwards. Fix by reversing the assignment direction to match the source port pattern. Fixes: b0c19ed6088a ("sch_cake: Take advantage of skb->hash where appropriate") Signed-off-by: Dudu Lu <phx0fer@gmail.com> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> Link: https://patch.msgid.link/20260413110041.44704-1-phx0fer@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-16net: bridge: use a stable FDB dst snapshot in RCU readersZhengchuan Liang
Local FDB entries can be rewritten in place by `fdb_delete_local()`, which updates `f->dst` to another port or to `NULL` while keeping the entry alive. Several bridge RCU readers inspect `f->dst`, including `br_fdb_fillbuf()` through the `brforward_read()` sysfs path. These readers currently load `f->dst` multiple times and can therefore observe inconsistent values across the check and later dereference. In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change `f->dst` after the NULL check and before the `port_no` dereference, leading to a NULL-ptr-deref. Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each affected RCU reader and using that snapshot for the rest of the access sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()` with `WRITE_ONCE()` so the readers and writer use matching access patterns. Fixes: 960b589f86c7 ("bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address") Cc: stable@kernel.org Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Co-developed-by: Yuan Tan <yuantan098@gmail.com> Signed-off-by: Yuan Tan <yuantan098@gmail.com> Suggested-by: Xin Liu <bird@lzu.edu.cn> Tested-by: Ren Wei <enjou1224z@gmail.com> Signed-off-by: Zhengchuan Liang <zcliangcn@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/6570fabb85ecadb8baaf019efe856f407711c7b9.1776043229.git.zcliangcn@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-16net/sched: act_mirred: fix wrong device for mac_header_xmit check in ↵Dudu Lu
tcf_blockcast_redir In tcf_blockcast_redir(), when iterating block ports to redirect packets to multiple devices, the mac_header_xmit flag is queried from the wrong device. The loop sends to dev_prev but queries dev_is_mac_header_xmit(dev) — which is the NEXT device in the iteration, not the one being sent to. This causes tcf_mirred_to_dev() to make incorrect decisions about whether to push or pull the MAC header. When the block contains mixed device types (e.g., an ethernet veth and a tunnel device), intermediate devices get the wrong mac_header_xmit flag, leading to skb header corruption. In the worst case, skb_push_rcsum with an incorrect mac_len can exhaust headroom and panic. The last device in the loop is handled correctly (line 365-366 uses dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste oversight for the intermediate devices. Fix by using dev_prev instead of dev for the mac_header_xmit query, consistent with the device actually being sent to. Fixes: 42f39036cda8 ("net/sched: act_mirred: Allow mirred to block") Signed-off-by: Dudu Lu <phx0fer@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260413084927.71353-1-phx0fer@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>