kernel/git/next/linux-next.git/net/xfrm, branch stable

Merge tag 'ipsec-2026-08-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2026-08-20T18:38:14+00:00

Steffen Klassert says: ==================== pull request (net): ipsec 2026-08-18 1) xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full Tighten the secpath-depth check so a full chain can't write past xvec[]. 2) Add and revert "esp: do not unref managed frag pages in esp_ssg_unref()" The patch does not fully fully resolve the issue, a corrected version will follow. 3) xfrm: espintcp: fix UAF during close Synchronize espintcp close with the xfrm_trans_reinject work queue so the freed socket message isn't dereferenced again. 4) xfrm: drop ESP-in-TCP packets with no ingress device Drop queued ESP-in-TCP records whose saved ingress device has gone away, avoiding a NULL device deref in the XFRM input path. 5) xfrm: avoid lock inversion in nat keepalive work Split the NAT keepalive walk into a reference-collection phase and a per-state lock phase to break the AB-BA with state removal. This patch has some issues that are fixed with a followup patch. 6) xfrm: Fix skb double-free in xfrm_dev_direct_output() Stop freeing the skb unconditionally in xfrm_dev_direct_output(), letting local_out()'s result indicate when ownership has moved on. 7) xfrm: ah6: validate routing header segments_left Validate the segments_left/hdrlen invariant before rearranging the routing-header addresses, avoiding an OOB memmove on malformed HDRINCL packets. 8) xfrm: fix xfrm_state_construct() auth-trunc leak Detect an already-attached auth-trunc allocation by the pointer rather than inferring it from the algorithm id, so a prior attach isn't overwritten and lost. 9) xfrm: bound nat keepalive state collection Replace the per-state allocation in the NAT keepalive walk with a fixed-size batch that drains under BH-disabled locking and resumes from the cursor, bounding the worker's memory. * tag 'ipsec-2026-08-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: bound nat keepalive state collection Revert "esp: do not unref managed frag pages in esp_ssg_unref()" xfrm: fix xfrm_state_construct() auth-trunc leak xfrm: ah6: validate routing header segments_left xfrm: Fix skb double-free in xfrm_dev_direct_output() xfrm: avoid lock inversion in nat keepalive work xfrm: drop ESP-in-TCP packets with no ingress device xfrm: espintcp: fix UAF during close esp: do not unref managed frag pages in esp_ssg_unref() xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full ==================== Link: https://patch.msgid.link/20260818092920.653034-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski

xfrm: bound nat keepalive state collection

2026-08-18T05:35:01+00:00

The v1 nat keepalive fix allocates a GFP_ATOMIC object for every state while collecting references for phase two. This makes the worker's temporary memory use depend on the number of states and lets -ENOMEM abort the scan. Replace the allocated list with a fixed-size batch. When the batch is full, return a private walk status so xfrm_state_walk() leaves a cursor; drain the references after the walk releases xfrm_state_lock and resume from the cursor. This bounds temporary memory use and avoids the allocation failure path. The v1 fix also moved nat_keepalive_send() out of the walk callback. Keep the phase-two drain BH-disabled, as required by local_lock_nested_bh() used by the keepalive sockets. Fixes: 763fe700b7c5 ("xfrm: avoid lock inversion in nat keepalive work") Cc: stable@vger.kernel.org Cc: Eyal Birger Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Signed-off-by: Steffen Klassert

net: Const qualify ctl_tables that kmemdup unconditionally

2026-08-13T11:12:24+00:00

Const qualify clt_table arrays in the net directory that always pass a memory duplicate to sysctl register. The template would then be in .rodata and the kmemdup'ed array would be outside. Signed-off-by: Joel Granados Link: https://patch.msgid.link/20260810-jag-net_const_qualify-v4-2-77e888237c69@kernel.org Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

xfrm: fix xfrm_state_construct() auth-trunc leak

2026-07-28T08:48:18+00:00

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

xfrm: Fix skb double-free in xfrm_dev_direct_output()

2026-07-23T08:07:21+00:00

A return value other than 1 from local_out() means that the skb has been consumed or its ownership was transferred. xfrm_dev_direct_output() nevertheless frees the skb on this path, causing a double-free when netfilter drops the packet and invalidating any other owner. Return the local_out() result directly, matching the ownership handling in xfrm_output_resume(). Fixes: 5eddd76ec2fd ("xfrm: fix tunnel mode TX datapath in packet offload mode") Signed-off-by: Sanghyun Park Signed-off-by: Steffen Klassert

xfrm: avoid lock inversion in nat keepalive work

2026-07-23T08:07:20+00:00

nat_keepalive_work() walks the state table while xfrm_state_walk() holds net->xfrm.xfrm_state_lock. Its callback then acquires x->lock, which conflicts with the delete path taking the same locks in reverse order via xfrm_state_delete() and __xfrm_state_delete(). This creates an AB-BA deadlock that is reported by lockdep when a NAT keepalive worker races with SA deletion. Fix this by splitting the keepalive walk into two phases. First, collect the candidate states while the walk holds xfrm_state_lock and take a reference on each state. Then, after the walk completes, process each collected state and acquire x->lock without nesting it under xfrm_state_lock. Fixes: f531d13bdfe3 ("xfrm: support sending NAT keepalives in ESP in UDP states") 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

Merge branch 'big-tcp-for-udp-tunnels'

2026-07-22T11:49:03+00:00

Alice Mikityanska says: ==================== BIG TCP for UDP tunnels This series is a follow-up to "BIG TCP without HBH in IPv6", and it adds support for BIG TCP IPv4/IPv6 workloads in vxlan and geneve. Now that IPv6 BIG TCP doesn't require stripping the HBH in all various combinations in tunneled traffic, adding BIG TCP becomes feasible. Patch 01 adds accessors for the length field in the UDP header, as suggested by Paolo in review. The usage of udp_set_len is then added in the following patches that start using length=0 in BIG TCP UDP packets. Patches 02-04 close the gaps that prevent BIG TCP packets from going through UDP tunnel code. Patch 05 validates packets in udp_gro_receive to exclude packets with length=0 from GRO aggregation. Patch 06 is for proper formatting in tcpdump (set UDP len to 0 rather than a trimmed value on overflow). Patches 07-08 bump up tso_max_size for VXLAN and GENEVE. Patch 09 adds selftests. ====================$ Link: https://patch.msgid.link/20260710134242.216538-1-alice.kernel@fastmail.im Signed-off-by: Paolo Abeni

net: Use helpers to get/set UDP len tree-wide

2026-07-22T11:47:02+00:00

Since BIG TCP for UDP tunnels will start using len=0 in the UDP header as an indicator of a GSO packet bigger than 65535 bytes, this commit introduces the following getter and setters to use tree-wide, in order to explicitly mark places where len=0 may be expected, and handle them properly: 1. udp_set_len() sets uh->len to its real value if it's not bigger than 65535, and to 0 otherwise: to be used in GSO context with aggregated packets. 2. udp_set_len_short() is to be used when the length is known to fit 16 bits. It WARNs when the caller tries to assign a bigger value if CONFIG_DEBUG_NET=y. 3. udp_get_len_short() returns len in host byte order: to be used on the RX side to deal with non-aggregated packets, or to access the raw value of the len field. 4. udp_get_len() decodes uh->len set by udp_set_len(). It checks whether the packet is GSO to guard from malformed packets. At the moment udp_set_len() is not used, a following commit will start using it after enabling len>65535 for GSO. Raw uh->len (in network byte order) is still accessed in a few places for checksum calculation purposes, and to decode len=0 in udpv6_rcv for jumbograms. udp_rcv and udpv6_rcv will be addressed by the commit that starts using udp_set_len() to set UDP len=0 for BIG TCP packets in UDP tunnels. Signed-off-by: Alice Mikityanska Reviewed-by: Willem de Bruijn Acked-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260710134242.216538-2-alice.kernel@fastmail.im Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni

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

2026-07-20T10:24:33+00:00

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

xfrm: espintcp: fix UAF during close

2026-07-20T10:21:12+00:00

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