From bac7a60e267831471ecdf54881fc62a2c80c446c Mon Sep 17 00:00:00 2001 From: Antony Antony Date: Tue, 26 May 2026 21:08:17 +0200 Subject: xfrm: add state synchronization after migration Add xfrm_migrate_sync() to copy curlft and replay state from the old SA to the new one before installation. The function allocates no memory, so it can be called under a spinlock. In preparation for a subsequent patch in this series. A subsequent patch calls this under x->lock, atomically capturing the latest lifetime counters and replay state from the original SA and deleting it in the same critical section to prevent SN/IV reuse for XFRM_MSG_MIGRATE_STATE method. No functional change. Signed-off-by: Antony Antony Signed-off-by: Steffen Klassert --- include/net/xfrm.h | 46 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/net/xfrm.h b/include/net/xfrm.h index 4137986f15e2..be22c26e4661 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -2024,23 +2024,51 @@ static inline unsigned int xfrm_replay_state_esn_len(struct xfrm_replay_state_es #ifdef CONFIG_XFRM_MIGRATE static inline int xfrm_replay_clone(struct xfrm_state *x, - struct xfrm_state *orig) + const struct xfrm_state *orig) { + /* Counters synced later in xfrm_replay_sync() */ - x->replay_esn = kmemdup(orig->replay_esn, + x->replay = orig->replay; + x->preplay = orig->preplay; + + if (orig->replay_esn) { + x->replay_esn = kmemdup(orig->replay_esn, xfrm_replay_state_esn_len(orig->replay_esn), GFP_KERNEL); - if (!x->replay_esn) - return -ENOMEM; - x->preplay_esn = kmemdup(orig->preplay_esn, - xfrm_replay_state_esn_len(orig->preplay_esn), - GFP_KERNEL); - if (!x->preplay_esn) - return -ENOMEM; + if (!x->replay_esn) + return -ENOMEM; + x->preplay_esn = kmemdup(orig->preplay_esn, + xfrm_replay_state_esn_len(orig->preplay_esn), + GFP_KERNEL); + if (!x->preplay_esn) + return -ENOMEM; + } return 0; } +static inline void xfrm_replay_sync(struct xfrm_state *x, const struct xfrm_state *orig) +{ + x->replay = orig->replay; + x->preplay = orig->preplay; + + if (orig->replay_esn) { + memcpy(x->replay_esn, orig->replay_esn, + xfrm_replay_state_esn_len(orig->replay_esn)); + + memcpy(x->preplay_esn, orig->preplay_esn, + xfrm_replay_state_esn_len(orig->preplay_esn)); + } +} + +static inline void xfrm_migrate_sync(struct xfrm_state *x, + const struct xfrm_state *orig) +{ + /* called under lock so no race conditions or mallocs allowed */ + memcpy(&x->curlft, &orig->curlft, sizeof(x->curlft)); + xfrm_replay_sync(x, orig); +} + static inline struct xfrm_algo_aead *xfrm_algo_aead_clone(struct xfrm_algo_aead *orig) { return kmemdup(orig, aead_len(orig), GFP_KERNEL); -- cgit v1.2.3