From e7a37c9e428a2912a4eec160e633503cd72e1ee6 Mon Sep 17 00:00:00 2001 From: Zilin Guan Date: Wed, 14 May 2025 08:48:39 +0000 Subject: [PATCH] xfrm: use kfree_sensitive() for SA secret zeroization High-level copy_to_user_* APIs already redact SA secret fields when redaction is enabled, but the state teardown path still freed aead, aalg and ealg structs with plain kfree(), which does not clear memory before deallocation. This can leave SA keys and other confidential data in memory, risking exposure via post-free vulnerabilities. Since this path is outside the packet fast path, the cost of zeroization is acceptable and prevents any residual key material. This patch replaces those kfree() calls unconditionally with kfree_sensitive(), which zeroizes the entire buffer before freeing. Signed-off-by: Zilin Guan Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_state.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 4bf7a4a8f9d4..5e1c736ea708 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -599,9 +599,9 @@ static void ___xfrm_state_destroy(struct xfrm_state *x) x->mode_cbs->destroy_state(x); hrtimer_cancel(&x->mtimer); timer_delete_sync(&x->rtimer); - kfree(x->aead); - kfree(x->aalg); - kfree(x->ealg); + kfree_sensitive(x->aead); + kfree_sensitive(x->aalg); + kfree_sensitive(x->ealg); kfree(x->calg); kfree(x->encap); kfree(x->coaddr); -- 2.50.1