From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.secunet.com (mx1.secunet.com [62.96.220.36]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2FB74448CE4 for ; Tue, 18 Aug 2026 09:29:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.96.220.36 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787045381; cv=none; b=ri9hx3dl88uCGNPp7X5N83cShH2rSAbXhYRZZHmG0ARsnGM1cKgXmq5dZuqHX3Rxd33LdwlWqC2OvILrQnH83dmtp2Wn1nK7xPLlunRa2ZuJxMCHRHPlucpDNBzEfg7HOcZLnWtiL7LdlCJuYfytb0VvCz8PunXujkat8naNud0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787045381; c=relaxed/simple; bh=K4cF+Ze9/ENrN0cyjlIoItdHHsW7pXdTphwSycmx2go=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SiWNsyU5ZM004G0YnXpSkkCAUL500OMUUsoxHmxRkNmWHsTl3NXHD58xekRKzU+a5HlxdJRpqpsUXD1riUc/YXI8LU0TbfvMYRKiGV+dYxeM8InJOY9RCYLcXfA6eeIQ4uXUKXEf2nvEMHIx+raJ9+sHC6Y/NgELPQPrQyZQByU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com; spf=pass smtp.mailfrom=secunet.com; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b=zP7RuoTc; arc=none smtp.client-ip=62.96.220.36 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=secunet.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=secunet.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b="zP7RuoTc" Received: from localhost (localhost [127.0.0.1]) by mx1.secunet.com (Postfix) with ESMTP id 4361E20728; Tue, 18 Aug 2026 11:29:37 +0200 (CEST) X-Virus-Scanned: by secunet Received: from mx1.secunet.com ([127.0.0.1]) by localhost (mx1.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nj4SzJ0pBr0c; Tue, 18 Aug 2026 11:29:36 +0200 (CEST) Received: from EXCH-01.secunet.de (rl1.secunet.de [10.32.0.231]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.secunet.com (Postfix) with ESMTPS id 8D740201D3; Tue, 18 Aug 2026 11:29:36 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.secunet.com 8D740201D3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=secunet.com; s=202301; t=1787045376; bh=8occ4Cbc5vqEhKnpMqwdgfXCD6BV5xbHB/Ugc2egV4c=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=zP7RuoTcQGQTEqdrqY+niH3qRehPjFQMSmy6Cqhu0j2f9+/b94Et+Q8ZcQuUSUxyc RxVbyLIOif4yXiLB6ClMYRG1xng4NS6Ku9WFJSqFcyO+ukKSypEstrxIEyPPS0G4ce xqvGVqvIXV9CewFd0SOsFOZsirZRhavfcaGP1FDQFcC89nkRmwKTyI5B6O9wuxd0ip Sa6d8OvmF75zHNsAEGfpZ1UkNaNNLtcj9VaJiXiqbgJ5k7XELSc7jKlvx5UqFTdj37 2xz5m0SU0PetasZTLt6gv8IvqnOBdHA73mkfI6eglJ4XZNMtikMSzHUl9ZCYYqEFcY 0J9+g76Sv/vgQ== Received: from secunet.com (10.182.7.193) by EXCH-01.secunet.de (10.32.0.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Tue, 18 Aug 2026 11:29:34 +0200 Received: (nullmailer pid 657509 invoked by uid 1000); Tue, 18 Aug 2026 09:29:27 -0000 From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 10/10] xfrm: bound nat keepalive state collection Date: Tue, 18 Aug 2026 11:28:41 +0200 Message-ID: <20260818092920.653034-11-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260818092920.653034-1-steffen.klassert@secunet.com> References: <20260818092920.653034-1-steffen.klassert@secunet.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EXCH-01.secunet.de (10.32.0.171) To EXCH-01.secunet.de (10.32.0.171) From: Zihan Xi The v1 nat keepalive fix allocates a GFP_ATOMIC object for every state while collecting references for phase two. This makes the worker's temporary memory use depend on the number of states and lets -ENOMEM abort the scan. Replace the allocated list with a fixed-size batch. When the batch is full, return a private walk status so xfrm_state_walk() leaves a cursor; drain the references after the walk releases xfrm_state_lock and resume from the cursor. This bounds temporary memory use and avoids the allocation failure path. The v1 fix also moved nat_keepalive_send() out of the walk callback. Keep the phase-two drain BH-disabled, as required by local_lock_nested_bh() used by the keepalive sockets. Fixes: 763fe700b7c5 ("xfrm: avoid lock inversion in nat keepalive work") Cc: stable@vger.kernel.org Cc: Eyal Birger Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_nat_keepalive.c | 46 ++++++++++++++++------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/net/xfrm/xfrm_nat_keepalive.c b/net/xfrm/xfrm_nat_keepalive.c index 8679c68c10a1..5cd6d43164db 100644 --- a/net/xfrm/xfrm_nat_keepalive.c +++ b/net/xfrm/xfrm_nat_keepalive.c @@ -155,32 +155,30 @@ static void nat_keepalive_send(struct nat_keepalive *ka) } } +enum { + NAT_KEEPALIVE_BATCH_SIZE = 16, + NAT_KEEPALIVE_BATCH_FULL = 1, +}; + struct nat_keepalive_work_ctx { - struct list_head states; + struct xfrm_state *batch[NAT_KEEPALIVE_BATCH_SIZE]; + unsigned int nr; time64_t next_run; time64_t now; }; -struct nat_keepalive_state { - struct list_head list; - struct xfrm_state *x; -}; - static int nat_keepalive_work_collect(struct xfrm_state *x, int count, void *ptr) { struct nat_keepalive_work_ctx *ctx = ptr; - struct nat_keepalive_state *state; if (!READ_ONCE(x->nat_keepalive_interval)) return 0; - state = kmalloc_obj(*state, GFP_ATOMIC); - if (!state) - return -ENOMEM; + if (ctx->nr == ARRAY_SIZE(ctx->batch)) + return NAT_KEEPALIVE_BATCH_FULL; xfrm_state_hold(x); - state->x = x; - list_add_tail(&state->list, &ctx->states); + ctx->batch[ctx->nr++] = x; return 0; } @@ -226,29 +224,27 @@ static void nat_keepalive_work_single(struct xfrm_state *x, static void nat_keepalive_work(struct work_struct *work) { - struct nat_keepalive_state *state, *tmp; struct nat_keepalive_work_ctx ctx; struct xfrm_state_walk walk; struct net *net; - int err; + int err, i; - INIT_LIST_HEAD(&ctx.states); ctx.next_run = 0; ctx.now = ktime_get_real_seconds(); net = container_of(work, struct net, xfrm.nat_keepalive_work.work); xfrm_state_walk_init(&walk, IPPROTO_ESP, NULL); - err = xfrm_state_walk(net, &walk, nat_keepalive_work_collect, &ctx); + do { + ctx.nr = 0; + err = xfrm_state_walk(net, &walk, nat_keepalive_work_collect, &ctx); + local_bh_disable(); + for (i = 0; i < ctx.nr; i++) { + nat_keepalive_work_single(ctx.batch[i], &ctx); + xfrm_state_put(ctx.batch[i]); + } + local_bh_enable(); + } while (err == NAT_KEEPALIVE_BATCH_FULL); xfrm_state_walk_done(&walk, net); - list_for_each_entry_safe(state, tmp, &ctx.states, list) { - nat_keepalive_work_single(state->x, &ctx); - xfrm_state_put(state->x); - kfree(state); - } - if (err == -ENOMEM) { - schedule_delayed_work(&net->xfrm.nat_keepalive_work, 0); - return; - } if (ctx.next_run) schedule_delayed_work(&net->xfrm.nat_keepalive_work, (ctx.next_run - ctx.now) * HZ); -- 2.43.0