kernel/linux.git/net/xfrm, branch v7.2-rc1

Merge tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2026-06-23T23:22:24+00:00

Steffen Klassert says: ==================== pull request (net): ipsec 2026-06-22 1) xfrm: use compat translator only for u64 alignment mismatch Gate the XFRM_USER_COMPAT translator on COMPAT_FOR_U64_ALIGNMENT so 32-bit compat tasks on arches whose 32-bit ABI already matches the native 64-bit layout are no longer rejected with -EOPNOTSUPP. From Sanman Pradhan. 2) net: af_key: initialize alg_key_len for IPComp states Initialize the alg_key_len to 0 in the IPComp branch of pfkey_msg2xfrm_state() so an uninitialized value cannot drive xfrm_alg_len() into a slab-out-of-bounds kmemdup during XFRM_MSG_MIGRATE. From Zijing Yin. 3) xfrm: Fix dev use-after-free in xfrm async resumption Stash the original skb->dev and extend the RCU critical section across xfrm_rcv_cb() and transport_finish() to prevent a tunnel-device UAF and original-device refcount leak when a callback replaces skb->dev. From Dong Chenchen. 4) xfrm: Fix xfrm state cache insertion race Move the state-validity check inside xfrm_state_lock in the input state cache insertion path so a state cannot be killed between the check and the insert. From Herbert Xu. 5) xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] Add READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count and xfrm_policy_default to silence the KCSAN data race reported on net->xfrm.policy_count. From Eric Dumazet. 6) espintcp: use sk_msg_free_partial to fix partial send Replace the manual skmsg accounting in espintcp with sk_msg_free_partial() so the skmsg stays consistent on every iteration and the partial-send accounting bugs go away. From Sabrina Dubroca. 7) xfrm: validate selector family and prefixlen during match Reject mismatched address families in xfrm_selector_match() and bound prefixlen in addr4_match()/addr_match() to prevent the shift-out-of-bounds syzbot reported when an AF_UNSPEC selector with a large prefixlen is matched against an IPv4 flow. From Eric Dumazet. * tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: validate selector family and prefixlen during match espintcp: use sk_msg_free_partial to fix partial send xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] xfrm: Fix xfrm state cache insertion race xfrm: Fix dev use-after-free in xfrm async resumption net: af_key: initialize alg_key_len for IPComp states xfrm: use compat translator only for u64 alignment mismatch ==================== Link: https://patch.msgid.link/20260622075726.29685-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski

xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelink

2026-06-17T23:01:53+00:00

xfrmi_changelink() operates on at most two netns, dev_net(dev) and the interface link netns xi->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in xi->net can rewrite an interface that lives in xi->net. Gate xfrmi_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed. Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-8-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski

xfrm: validate selector family and prefixlen during match

2026-06-17T09:17:27+00:00

syzbot reported a shift-out-of-bounds in xfrm_selector_match() due to AF_UNSPEC selector with large prefixlen (e.g. 128) matched against IPv4 flow (when XFRM_STATE_AF_UNSPEC is set). Fix this by: - Rejecting mismatched families in xfrm_selector_match. - Returning false in addr4_match if prefixlen > 32. - Returning false in addr_match if prefixlen > 128 (prevents overflow). Fixes: 3f0ab59e6537 ("xfrm: validate new SA's prefixlen using SA family when sel.family is unset") Reported-by: syzbot+9383b1ff0df4b29ca5e6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a2fbe35.be3f099c.2836ae.0018.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Signed-off-by: Steffen Klassert

espintcp: use sk_msg_free_partial to fix partial send

2026-06-17T09:17:27+00:00

sk_msg_free_partial() ensures consistency of the skmsg at every iteration, without having to manually handle uncharges and offsets. This simplifies the code, and fixes some bugs in skmsg accounting when we don't send the full contents. Cc: stable@vger.kernel.org Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: Aaron Esau Reported-by: Yiming Qian Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert

xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]

2026-06-17T09:17:26+00:00

KCSAN reported a data race involving net->xfrm.policy_count access. Add missing READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count and xfrm_policy_default. Fixes: 2518c7c2b3d7 ("[XFRM]: Hash policies when non-prefixed.") Reported-by: syzbot+d85ba1c732720b9a4097@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a2b9e96.99669fcc.12a77b.0006.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Signed-off-by: Steffen Klassert

xfrm: Fix xfrm state cache insertion race

2026-06-17T09:17:17+00:00

The xfrm input state cache insertion code checks the validity of the state before acquiring the global xfrm_state_lock. Thus it's possible for someone else to kill the state after it passed the validity check, and then the insertion will add the dead state to the cache. Fix this by moving the validity check inside the lock. This entire function is called on the input path, where BH must be off (e.g., the caller of this function xfrm_input acquires its spinlocks without disabling BH). So there is no need to disable BH here or take the RCU read lock. Remove both and replace them with an assertion that trips if BH is accidentally enabled on some future calling path. Fixes: 81a331a0e72d ("xfrm: Add an inbound percpu state cache.") Reported-by: Zero Day Initiative Signed-off-by: Herbert Xu Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert

Merge tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

2026-06-13T20:16:39+00:00

Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2026-06-12 1) Replace the open-coded manual cleanup in xfrm_add_policy() error path with xfrm_policy_destroy() for consistency with xfrm_policy_construct(). From Deepanshu Kartikey. 2) Limit XFRMA_TFCPAD to a sensible maximum (max IP length, 64k) since u32 is excessive for traffic flow confidentiality padding. From David Ahern. 3) Add a new netlink message XFRM_MSG_MIGRATE_STATE that allows migrating individual IPsec SAs independently of their policies. The existing XFRM_MSG_MIGRATE is tightly coupled to policy+SA migration, lacks SPI for unique SA identification, and cannot express reqid changes or migrate Transport mode selectors. The new interface identifies the SA via SPI and mark, supports reqid changes, address family changes, encap removal, and uses an atomic create+install flow under x->lock to prevent SN/IV reuse during AEAD SA migration. From Antony Antony. * tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next: xfrm: add documentation for XFRM_MSG_MIGRATE_STATE xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATE xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration xfrm: make xfrm_dev_state_add xuo parameter const xfrm: extract address family and selector validation helpers xfrm: refactor XFRMA_MTIMER_THRESH validation into a helper xfrm: move encap and xuo into struct xfrm_migrate xfrm: add error messages to state migration xfrm: add state synchronization after migration xfrm: check family before comparing addresses in migrate xfrm: split xfrm_state_migrate into create and install functions xfrm: rename reqid in xfrm_migrate xfrm: fix NAT-related field inheritance in SA migration xfrm: allow migration from UDP encapsulated to non-encapsulated ESP xfrm: add extack to xfrm_init_state xfrm: remove redundant assignments xfrm: Reject excessive values for XFRMA_TFCPAD xfrm: cleanup error path in xfrm_add_policy() ==================== Link: https://patch.msgid.link/20260612074725.1760473-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski

xfrm: Fix dev use-after-free in xfrm async resumption

2026-06-12T06:39:59+00:00

xfrm async resumption hold skb->dev refcnt until after transport_finish. However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking device reference, such as vti_rcv_cb. The subsequent async resumption will decrement the tunnel device's reference count, which lead to uaf of tunnel dev and refcnt leak of orig dev as below: unregister_netdevice: waiting for vti1 to become free. Usage count = -2 Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set by xfrm_rcv_cb can race with device teardown. Extend rcu protection over xfrm_rcv_cb and transport_finish to prevent races. Fixes: 1c428b038400 ("xfrm: hold dev ref until after transport_finish NF_HOOK") Reported-by: Xu Chunxiao Signed-off-by: Dong Chenchen Signed-off-by: Steffen Klassert

xfrm: use compat translator only for u64 alignment mismatch

2026-06-12T06:38:48+00:00

The XFRM compat layer (CONFIG_XFRM_USER_COMPAT) translates 32-bit xfrm netlink and setsockopt messages into the native 64-bit layout. It is only needed on architectures where the 32-bit and 64-bit ABIs disagree on u64 alignment, which the kernel encodes as COMPAT_FOR_U64_ALIGNMENT. That symbol is defined only by arch/x86. XFRM_USER_COMPAT depends on it, so the translator can never be built on any other architecture, including arm64, which still provides a 32-bit compat ABI (CONFIG_COMPAT) for AArch32 EL0 userspace. On arm64 the AArch32 EABI already aligns u64 to 8 bytes, identical to the AArch64 ABI, so no translation is required and the native code path is correct for 32-bit tasks. However, xfrm_user_rcv_msg() and xfrm_user_policy() gate on in_compat_syscall() alone and then call xfrm_get_translator(), which returns NULL when no translator is registered. On arm64 that is always the case, so every xfrm netlink message and the XFRM_POLICY setsockopt issued by a 32-bit task returns -EOPNOTSUPP. A 32-bit userspace process on arm64 (and on any other arch with CONFIG_COMPAT but without COMPAT_FOR_U64_ALIGNMENT) therefore cannot configure XFRM state or policy through the XFRM_USER netlink API, and cannot use the XFRM_POLICY setsockopt path, because both fail before reaching the native parser. The translator series replaced the blanket compat rejection with a translator lookup. That made the path usable on x86 when the translator is available, but left architectures that cannot build the translator permanently rejected even when their compat layout already matches the native layout. Let those architectures use the native parser instead. Gate the translator requirement on COMPAT_FOR_U64_ALIGNMENT instead of on in_compat_syscall() alone. Gating on the ABI property rather than on CONFIG_XFRM_USER_COMPAT is deliberate: on x86 with IA32_EMULATION=y but XFRM_USER_COMPAT=n, a 32-bit task must still be rejected rather than routed through the native parser, which would misread genuinely 4-byte-aligned x86-32 messages. COMPAT_FOR_U64_ALIGNMENT is the ABI property that makes the XFRM translator mandatory. Only the receive/input direction needs the guard. The send, dump and notification paths already call the translator as "if (xtr) { ... }" with no error on NULL, so on arches without a translator they no-op and the kernel emits native 64-bit-layout messages, which is what an AArch32 task expects. Tested on Juniper SRX hardware: with the fix, 32-bit IPsec userspace netlink and XFRM_POLICY setsockopt operations that previously failed with -EOPNOTSUPP now succeed; x86 behaviour is unchanged by inspection. Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Fixes: 96392ee5a13b ("xfrm/compat: Translate 32-bit user_policy from sockptr") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan Signed-off-by: Steffen Klassert

xfrm: espintcp: do not reuse an in-progress partial send

2026-06-05T11:20:03+00:00

espintcp keeps a single in-flight transmit in ctx->partial. Before building a new sk_msg, espintcp_sendmsg() first tries to flush that state through espintcp_push_msgs(). For blocking callers, espintcp_push_msgs() may return success even when the previous partial send is still pending. espintcp_sendmsg() would then reinitialize emsg->skmsg and reuse ctx->partial while the old transfer still owns that state. Do not rebuild the send message when ctx->partial is still in progress. If espintcp_push_msgs() returns with emsg->len still set, fail the new send instead of overwriting the live partial state. This is a memory-safety fix: reusing the live partial-send state can leave a stale offset attached to a new sk_msg and lead to an out-of- bounds read in the send path. tcp_sendmsg_locked() already handles waiting for send buffer memory, so the fix here is just to preserve espintcp's one-message-at-a-time transmit state. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Cc: stable@kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Wyatt Feng Signed-off-by: Ren Wei Signed-off-by: Steffen Klassert