From: Zilin Guan Date: Wed, 14 May 2025 08:48:39 +0000 (+0000) Subject: xfrm: use kfree_sensitive() for SA secret zeroization X-Git-Tag: v6.16-rc1~132^2~31^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e7a37c9e428a2912a4eec160e633503cd72e1ee6;p=thirdparty%2Fkernel%2Flinux.git 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 --- diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 4bf7a4a8f9d44..5e1c736ea7089 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);