From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DABEC3D413D for ; Sat, 28 Feb 2026 22:18:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772317091; cv=none; b=A4tIhOqm1riQqEXPk5BlUSXjwhT5gmjoc/AvjwpSKVYCcPdsT01GtasTlviI0zc/0H571NCP27NIAO7Di1gc9UE2X/+qzgSrtu5Bm77/2HaNpYQYE+YK3S63cXHX7Bn+5oSnbhnUJ453gTdb92s8+xAGn+tdHZ8aDCgCfoCv1s8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772317091; c=relaxed/simple; bh=/sYz6Qa8y4VRFFDmV7lKHqBd9/K/XwopFBJDonKR5As=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IImvkJned8vsbEyNn74+BPZPRd7QLknBbhgurp0QjvWpoakHBxkCLHXuhsfCRsYMg3WuP5pl46LMw6Y6/D33e63JtejS52PI/sHsT8KER5Pq0BQcysnt7js2mEjRwBqZ8fD8B9snsH0WtJyoxhq2Ru7bA1MRZzwddr0eIMb1fqs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=JcxAFUQY; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="JcxAFUQY" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2ab0b2e804cso29630295ad.3 for ; Sat, 28 Feb 2026 14:18:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772317090; x=1772921890; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=RIMwfQGmexEev8GJ28YhfmS6vK7GLe46FYq3+TzSnwU=; b=JcxAFUQYt3fcNCTmQ+5fmnJoT6c0WqaC/lMOmxJ20vIbgq6L2P+POuaSdFlAItGLc+ QlQM6SfNqN1dfHHzjxDsCPQqdg0AD82rczSGKZ6+Zpd68U5AsYuBR95pIlyqiXhEJJOj FSpNHUE8JrgzyoJ+XSj9i7peJuJPH50bJ7LTlgnWw8A/ARpmmASG4BCEPg1WjTYkeIBl E4OKGg5Q1jOLrKyeGcAk+dQFw97HJTaa5xUA8wHj3gjK600rdyZqaCB+9t7J3lXIfVOH ydcK0qRTFrRJnSu51TY8I3RDyFAXNrj5vEbAe6hIFkvRtgczQ5xhsRbno6dGlhpdwqjG xjew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772317090; x=1772921890; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=RIMwfQGmexEev8GJ28YhfmS6vK7GLe46FYq3+TzSnwU=; b=wphITcBsSc9ymDKmpJFfk0FOim3klj5xCUfgTwXiw3aOWNXR7t2F9uNl+eMSpyLtml JaSEApsTyBrVnoD8A7qUmAUHAGUrXbZfXD1QxBKnE8h6rnapFS6/YBsEwbQm8popUySg B+e+nQEtsl95WPrqsT+NZuT7CF5XkuAB1QH2Dk52JRbkkWzw27pRIJ5X90HePWSxVx/Q qtjpM57vTh942e7XlRPo0L95uA3vwY0NdbQWPQloDOcAJdix6FOpZTGBUD461OjYZ8RV qzpLBHhh+S/7OBEzYjKmZ/otu1+2AghElj44816oKegNU7g438ZjENUIJAT8enDUbN6n 3A7w== X-Forwarded-Encrypted: i=1; AJvYcCXdmhEr7c0yiNAjFxyBUGZQ7Ktq3GvESi/Ca9N5/AHVGlLz0mIJwHzw7KFFpUIKdjo4KuEc9DA=@vger.kernel.org X-Gm-Message-State: AOJu0YxKJ3F59YOpqzYoFnIRt/cqni6pbfFcuNp0toAXh+ufTHCpvcDA EosE3SiJlK8l4cJ7P/I6ip/K1wFoYfjj8+8hAaZAxFf5+bQgtPsccRMZ2nUKRaVbYsTxRmCn9DK L2fvlkA== X-Received: from plbko3.prod.google.com ([2002:a17:903:7c3:b0:2a0:81d1:64f4]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:e743:b0:2a0:ba6d:d101 with SMTP id d9443c01a7336-2ae2e40b84emr62954645ad.21.1772317090030; Sat, 28 Feb 2026 14:18:10 -0800 (PST) Date: Sat, 28 Feb 2026 22:17:22 +0000 In-Reply-To: <20260228221800.1082070-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260228221800.1082070-1-kuniyu@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260228221800.1082070-5-kuniyu@google.com> Subject: [PATCH v3 net-next 04/15] ipmr: Use MAXVIFS in mroute_msgsize(). From: Kuniyuki Iwashima To: "David S . Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" mroute_msgsize() calculates skb size needed for ipmr_fill_mroute(). The size differs based on mrt->maxvif. We will drop RTNL for ipmr_rtm_getroute() and mrt->maxvif may change under RCU. To avoid -EMSGSIZE, let's calculate the size with the maximum value of mrt->maxvif, MAXVIFS. struct rtnexthop is 8 bytes and MAXVIFS is 32, so the maximum delta is 256 bytes, which is small enough. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet --- net/ipv4/ipmr.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index eecc79a835d1..9f2dd726affb 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -2510,7 +2510,7 @@ static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, cmd, flags); } -static size_t mroute_msgsize(bool unresolved, int maxvif) +static size_t mroute_msgsize(bool unresolved) { size_t len = NLMSG_ALIGN(sizeof(struct rtmsg)) @@ -2523,7 +2523,7 @@ static size_t mroute_msgsize(bool unresolved, int maxvif) len = len + nla_total_size(4) /* RTA_IIF */ + nla_total_size(0) /* RTA_MULTIPATH */ - + maxvif * NLA_ALIGN(sizeof(struct rtnexthop)) + + MAXVIFS * NLA_ALIGN(sizeof(struct rtnexthop)) /* RTA_MFC_STATS */ + nla_total_size_64bit(sizeof(struct rta_mfc_stats)) ; @@ -2538,8 +2538,7 @@ static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc, struct sk_buff *skb; int err = -ENOBUFS; - skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS, - mrt->maxvif), + skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS), GFP_ATOMIC); if (!skb) goto errout; @@ -2711,7 +2710,7 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, goto errout_free; } - skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL); + skb = nlmsg_new(mroute_msgsize(false), GFP_KERNEL); if (!skb) { err = -ENOBUFS; goto errout_free; -- 2.53.0.473.g4a7958ca14-goog