kernel/linux.git/net, branch v5.10.269

ipv6: seg6: clear IPv4 control block on IPIP decapsulation

2026-09-02T12:26:44+00:00

commit 44930446dde45a7a90fe1446fa38eb0e2c561646 upstream. End.DX4 and End.DT4 decapsulate an IPv4 packet through decap_and_validate() and send it directly to IPv4 routing. The inner packet therefore bypasses ip_rcv_core(), which normally clears IPCB before IPv4 interprets skb->cb. The skb instead retains IP6CB data from the outer packet. IP6CB and IPCB use the same skb->cb storage, so IP6CB(skb)->lastopt overlaps IPCB(skb)->opt.optlen and srr, while IP6CB(skb)->nhoff overlaps rr and ts. The sender can make the stale optlen byte nonzero with a valid outer extension-header chain. The reproducers put an eight-byte Destination Options header immediately after the 40-byte IPv6 header and before the Segment Routing Header. ipv6_destopt_rcv() records the sender-controlled Destination Options offset in both lastopt and nhoff, setting them to 40. On the reproduced little-endian x86-64 kernel, IPv4 therefore sees optlen = 40 and rr = 40. Both tcp_v4_save_options() and __ip_options_echo() skip option copying when optlen is zero. Here optlen is 40, so the TCP SYN path allocates room for 40 bytes of option data and calls __ip_options_echo(). The stale rr value makes that function read inner packet byte 41 as the Record Route option length. The reproducers set that sender-controlled byte to 255, so __ip_options_echo() copies 255 bytes into the 40-byte option-data area. Separate End.DX4 and End.DT4 reproducers on the unpatched v7.2-rc5 kernel both produced: BUG: KASAN: slab-out-of-bounds in __ip_options_echo() Write of size 255 The relevant End.DX4 call path is: __ip_options_echo tcp_v4_route_req tcp_conn_request tcp_v4_conn_request tcp_rcv_state_process tcp_v4_do_rcv tcp_v4_rcv ip_protocol_deliver_rcu ip_local_deliver_finish ip_local_deliver input_action_end_dx4_finish input_action_end_dx4 The relevant End.DT4 call path is: __ip_options_echo tcp_v4_route_req tcp_conn_request tcp_v4_conn_request tcp_rcv_state_process tcp_v4_do_rcv tcp_v4_rcv ip_protocol_deliver_rcu ip_local_deliver_finish ip_local_deliver input_action_end_dt4 tcp_v4_save_options() is inlined into the tcp_v4_route_req() path, so it does not appear as a separate frame. When decap_and_validate() handles IPPROTO_IPIP, save the ingress interface from IP6CB, clear IPCB, and restore the saved value. Doing this in the common decapsulation path covers End.DX4, End.DT4, and End.DT46's IPv4 arm. Use IP6CB(skb)->iif rather than skb->skb_iif. These actions run after l3mdev processing, which can replace skb_iif with the L3 master; IP6CB iif still records the receiving interface set at IPv6 ingress. Fixes: 891ef8dd2a8d ("ipv6: sr: implement additional seg6local actions") Cc: stable@vger.kernel.org Suggested-by: Andrea Mayer Signed-off-by: Kyle Zeng Co-developed-by: David Lee Signed-off-by: David Lee Reviewed-by: Andrea Mayer Link: https://patch.msgid.link/20260817085839.946321-1-david.lee@trailofbits.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

xfrm: fix xfrm_state_construct() auth-trunc leak

2026-09-02T12:26:44+00:00

commit c12cbf56320fb633484ee0ca1fb7d68d6b64b213 upstream. attach_auth_trunc() can allocate x->aalg while leaving x->props.aalgo at zero when the selected auth algorithm has no sadb_alg_id. One real case is cmac(aes). xfrm_state_construct() then treats !x->props.aalgo as "no auth algorithm attached yet" and calls attach_auth(). That overwrites x->aalg and loses the first allocation. Any later failure or teardown only frees the replacement pointer. Check whether x->aalg is already attached instead of inferring that state from x->props.aalgo. Fixes: 4447bb33f094 ("xfrm: Store aalg in xfrm_state with a user specified truncation length") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Signed-off-by: Ren Wei Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

xfrm: ah6: validate routing header segments_left

2026-09-02T12:26:44+00:00

commit 7bad4bda74dc4713f398d3b7624ff05478e3a568 upstream. AH6 rearranges routing-header addresses before computing or verifying the ICV. ipv6_rearrange_rthdr() assumes that segments_left is not larger than the number of addresses described by the routing header's hdrlen field. That assumption does not hold for raw IPv6 HDRINCL packets. A packet with hdrlen equal to 2 describes one address, but can carry an arbitrary segments_left value. With segments_left equal to 255, the function moves its address pointer 4,064 bytes backwards and passes a 4,064-byte length to memmove(), resulting in an out-of-bounds access. Validate the invariant locally before modifying the routing header or performing any address-pointer arithmetic, and propagate malformed-header errors to the existing AH6 input and output error paths. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Assisted-by: avom-custom-harness:gpt-5.5-qwen3.6-mod-mix Signed-off-by: Asim Viladi Oglu Manizada Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

xfrm: drop ESP-in-TCP packets with no ingress device

2026-09-02T12:26:44+00:00

commit e1d7c5ac1c246ce5775f604515de0a59fbf2116e upstream. ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown. In that case dev_get_by_index_rcu() returns NULL. The XFRM IPv4 and IPv6 input paths both expect skb->dev to be valid while building the route lookup, so queued ESP-in-TCP data can dereference a NULL device. Drop the packet if the saved ingress device can no longer be resolved. Such a packet can no longer be routed through the normal XFRM receive path, and this preserves the existing behaviour for packets whose ingress device still exists. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Assisted-by: Codex:gpt-5.4 Reviewed-by: Ren Wei Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

xfrm: espintcp: fix UAF during close

2026-09-02T12:26:43+00:00

commit deb232e884877bf10b4ce2580909eedec986c284 upstream. ZDI reported and analyzed a race condition during close for espintcp sockets: espintcp_close() frees emsg->skb via kfree_skb() without holding any socket lock. Concurrently, the xfrm_trans_reinject work queue invokes esp_output_tcp_finish() -> espintcp_push_skb() -> espintcp_push_msgs() -> skb_send_sock_locked(), which reads the same skb as a data source. Fix this by adding a synchronize_rcu() call after resetting sk_prot, since esp_output_tcp_finish() runs under RCU and won't use a socket with sk_prot == &tcp_prot. Simply taking the socket lock in espintcp_close() could lead to leaks, if esp_output_tcp_finish() re-adds an skb in the slot we just freed. After this, the existing barrier() is no longer needed. Cc: stable@vger.kernel.org Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: zdi-disclosures@trendmicro.com Signed-off-by: Sabrina Dubroca Reviewed-by: Breno Leitao Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

nfc: nci: add data_len bound checks to activation parameter extractors

2026-09-02T12:26:43+00:00

[ Upstream commit 0428fa2c22e2ba0cff766d3b80d461e149102045 ] nci_extract_activation_params_iso_dep() and nci_extract_activation_params_nfc_dep() read an inner length byte from the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed kernel buffers, but neither function receives the caller-validated activation_params_len. A crafted NCI notification with activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or 50 (NFC-B) causes memcpy() to read that many bytes past the one valid byte in the activation params region -- a slab out-of-bounds read of kernel memory adjacent to the NCI skb. The sibling nci_extract_rf_params_*() family was given equivalent protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter validation for packet data"), but the two activation parameter extractors were not updated at that time. Add a data_len parameter to both functions, guard against an empty region before consuming the inner length byte, decrement the remaining count after consuming it, and clamp the copy length to what is actually available. Update both call sites to pass ntf.activation_params_len, which is already validated against the skb at ntf.c:801. Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Link: https://patch.msgid.link/20260612-b4-disp-6d52d8b0-v3-1-e26221f8826d@proton.me Signed-off-by: David Heidelberg Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nfc: nci: fix uninit-value in the RF discover/activated NTF handlers

2026-09-02T12:26:43+00:00

[ Upstream commit 8cbe06c1e699c0a165dae5093a2550e65f914818 ] nci_rf_discover_ntf_packet() and nci_rf_intf_activated_ntf_packet() each parse a notification into an on-stack struct (nci_rf_discover_ntf / nci_rf_intf_activated_ntf) that is not initialised. The RF technology-specific parameters are only extracted when rf_tech_specific_params_len is non-zero, so a notification that reports a zero length leaves the rf_tech_specific_params union uninitialised - and both handlers then pass it to nci_add_new_protocol(), which reads it: - discover: nci_add_new_target() -> nci_add_new_protocol(); - activated: nci_target_auto_activated() -> nci_add_new_protocol(). nci_add_new_protocol() uses nfca_poll->nfcid1_len as both a branch condition and a memcpy() length and copies nfcid1/sens_res/sel_res into ndev->targets, which is later exposed to user space via NFC_CMD_GET_TARGET. BUG: KMSAN: uninit-value in nci_add_new_protocol+0x624/0x6c0 nci_add_new_protocol+0x624/0x6c0 nci_ntf_packet+0x25b2/0x3c30 nci_rx_work+0x318/0x5d0 process_scheduled_works+0x84b/0x17a0 worker_thread+0xc10/0x11b0 kthread+0x376/0x500 Local variable ntf.i created at: nci_ntf_packet+0xbc2/0x3c30 Zero-initialise both on-stack notifications so the union reads back as zero when no technology-specific parameters are present. Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support") Fixes: e8c0dacd9836 ("NFC: Update names and structs to NCI spec 1.0 d18") Link: https://lore.kernel.org/netdev/20260623172109.1105965-2-horms@kernel.org/ Cc: stable@vger.kernel.org Assisted-by: Bynario AI Signed-off-by: Samuel Page Link: https://patch.msgid.link/20260626090301.2139500-1-sam@bynar.io Signed-off-by: David Heidelberg Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()

2026-09-02T12:26:43+00:00

commit 7b19c0f81ed1fdaec6bc522569be367199a9edf3 upstream. A race condition exists between device teardown (inetdev_destroy) and incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free in the IGMP timer callback. During device destruction, inetdev_destroy() drops the primary reference to in_device, which can drop its refcount to 0. The actual freeing of in_device memory is deferred via RCU (using call_rcu()). Concurrently, igmp_rcv() runs under RCU read lock and obtains the in_device pointer. Because the memory is RCU-protected, CPU-0 can safely dereference in_device even if its refcount has hit 0. However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it attempts to acquire a reference using in_dev_hold(). This increments the refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning. Since the in_device memory is still scheduled to be freed after the RCU grace period (as the free callback does not check the refcount again), the device is freed while the timer is still armed. When the timer expires, it accesses the freed memory, causing a kernel panic. Fix this by using refcount_inc_not_zero() (via a new helper in_dev_hold_safe()) to prevent acquiring a reference if the device is already being destroyed. If the refcount is 0, we do not arm the timer. A similar issue in IPv6 MLD is fixed in a subsequent patch. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Zero Day Initiative Signed-off-by: Eric Dumazet Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260705181756.963063-2-edumazet@google.com Signed-off-by: Paolo Abeni [Denis Arefev: adapted for 5.10/5.15: keep prandom_u32(), get_random_u32_below() not used here] Signed-off-by: Denis Arefev Signed-off-by: Greg Kroah-Hartman

bpf: Remove tst_run from lwt_seg6local_prog_ops.

2026-09-02T12:26:42+00:00

[ Upstream commit c13fda93aca118b8e5cd202e339046728ee7dddb ] The syzbot reported that the lwt_seg6 related BPF ops can be invoked via bpf_test_run() without without entering input_action_end_bpf() first. Martin KaFai Lau said that self test for BPF_PROG_TYPE_LWT_SEG6LOCAL probably didn't work since it was introduced in commit 04d4b274e2a ("ipv6: sr: Add seg6local action End.BPF"). The reason is that the per-CPU variable seg6_bpf_srh_states::srh is never assigned in the self test case but each BPF function expects it. Remove test_run for BPF_PROG_TYPE_LWT_SEG6LOCAL. Suggested-by: Martin KaFai Lau Reported-by: syzbot+608a2acde8c5a101d07d@syzkaller.appspotmail.com Fixes: d1542d4ae4df ("seg6: Use nested-BH locking for seg6_bpf_srh_states.") Fixes: 004d4b274e2a ("ipv6: sr: Add seg6local action End.BPF") Signed-off-by: Sebastian Andrzej Siewior Acked-by: Daniel Borkmann Link: https://lore.kernel.org/r/20240710141631.FbmHcQaX@linutronix.de Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin

ipvs: reload ip header after head reallocation

2026-09-02T12:26:42+00:00

commit a2f57827bf7c695b8c72dc4511cae8e86582369d upstream. __ip_vs_get_out_rt() calls skb_ensure_writable() which may reallocate skb->head. Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-sonnet-4-6 Acked-by: Julian Anastasov Signed-off-by: Florian Westphal [Denis Arefev: adapted for 5.10/6.1: keep EnterFunction/LeaveFunction instrumentation] Signed-off-by: Denis Arefev Signed-off-by: Sasha Levin