[PATCH ipsec v5 0/9] xfrm: state: exact mark/mask match for control-plane SA lookups

[Antony Antony <antony.antony@secunet.com>]

While looking into a XFRM_MSG_MIGRATE_STATE issue reported by Sashiko,
we found the underlying problem generalizes: xfrm allows multiple SAs
to coexist for the same (SPI, daddr, proto) differing only in mark,
and every netlink method that resolves "which SA" - xfrm get_sa(),
del_sa(), update, get_ae, new_ae, expire, migrate - uses the same
wildcard mark match the data path needs. A broader-mask SA can
silently shadow a more specific one:

  # ip xfrm state add ... spi 0x1000 mark 1 mask 1 (SA_target)
  # ip xfrm state add ... spi 0x1000 mark 0 mask 0
    (SA_decoy, catch-all, added after -> bucket head)
  # ip xfrm state delete dst ... proto esp spi 0x1000 mark 1 mask 1
    -> deletes SA_decoy; SA_target survives, untouched

xfrm policy had the same bug, fixed in commit 4f47e8ab6ab7
("xfrm: policy: match with both mark and mask on user interfaces").

Netlink state lookups using spi use an exact mark/mask match except
for UPDSA; the wildcard match stays for the data path and state_add only.
This series applies that fix across every affected method,
not just XFRM_MSG_MIGRATE_STATE.

Also reject marks with value bits outside the mask (state ADD,
ALLOCSPI, policy ADD, MIGRATE_STATE new mark). These are
misconfigurations anyway, since the extra bits can never match, and
break exact match added here.

This series does not touch PF_KEY, which no longer receives
non-critical fixes.

state_lookup_byaddr is out of scope. This is only fixing spi based
lookups.

---
v4->v5: policy: drop the redundant mark sanitize in xfrm_policy_insert()
      - tweak commit messages

- Link to v4: https://patch.msgid.link/migrate-state-fixes-v4-0-d5054459fc78@secunet.com
v3->v4: add 3 patches to reject mark value bits outside the mask for state and policy

- Link to v3: https://patch.msgid.link/migrate-state-fixes-v3-6-836125bb53dd@secunet.com

v2->v3: mark match use only values and no mask in exact lookup

- Link to v2: https://lore.kernel.org/all/migrate-state-fixes-v2-0-c3e2767f0d96@secunet.com/
v1->v2: few more wildcard mark check reported by sashiko and Yan
      - keep wildcard match in xfrm_state_update() (UPDSA)

- Link to v1: https://patch.msgid.link/migrate-state-fixes-v0-8-a69e8637ba3b@secunet.com
---

---
Antony Antony (9):
      xfrm: state: reject mark with bits outside its mask on add
      xfrm: state: reject mark with bits outside its mask on ALLOCSPI
      xfrm: policy: reject mark with bits outside its mask on add
      xfrm: state: exact mark/mask match for SPI-keyed control-plane SA lookups
      xfrm: fix use-after-free of migrated state in xfrm_do_migrate_state()
      xfrm: fix hw offload state leak on xfrm_do_migrate_state() error path
      xfrm: include mark in MIGRATE_STATE SA collision check
      xfrm: pass extack through to xfrm_init_replay() from xfrm_init_state()
      docs: xfrm: include mark in XFRM_MSG_MIGRATE_STATE EEXIST tuple

 .../networking/xfrm/xfrm_migrate_state.rst         |  25 +++--
 include/net/xfrm.h                                 |   7 ++
 net/xfrm/xfrm_policy.c                             |   3 -
 net/xfrm/xfrm_state.c                              | 101 +++++++++++++++++----
 net/xfrm/xfrm_user.c                               |  81 ++++++++++++-----
 5 files changed, 166 insertions(+), 51 deletions(-)
---
base-commit: 86de3a1118a16dbbbe5fabe9aa20ffb93c072ed5
change-id: migrate-state-fixes-063ee0342611

Best regards,
--  
Antony Antony <antony.antony@secunet.com>