From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 74CEC1C4609; Wed, 19 Feb 2025 08:57:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739955443; cv=none; b=TrMaXzEig7DQ+6b/fpJaFotYtoc9YlsRVBMj/tBqDL3dlwfGAdOrBTwRgqua600AeSvYhnvxRQnMClAn4yZV/+SiPq8+bSkBCyoJZ+am+Ocyz2wqo6XF/baw/yGc4D7WTiY2o46idwuGzcAFHjKrjHEBrKxV9gq7fnuYwqKJplE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739955443; c=relaxed/simple; bh=aQ4GRJzQ7SZSiH/d4BG/FB3yOV5Vdy3lBBwzFfW6v6o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=W9Ry1kNj3n6EKmsLdI07JAniodKsDakC7a4gyr/dZx5J7yw5xuVkHHtd2+S7ZM7RbH+3VWQMikUKi60uZfgcTZFxSZIVijDHgc0rXUnB1eQ+HEx2uilKLJNVY01MtZXMvpY7RwKtn8YaU/zarTKm/qut897EgOc5J7EdMQ1q1Ww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dN4P20Wq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dN4P20Wq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAECEC4CED1; Wed, 19 Feb 2025 08:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739955443; bh=aQ4GRJzQ7SZSiH/d4BG/FB3yOV5Vdy3lBBwzFfW6v6o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dN4P20WqddQWNFQZyLXyP4g0fUGN8EKYtYyyu+6JQe0j3m+7gWujhZ1ianCrq8WeY Dl4HUvsxsUTF0ip4J7W3/GNnLd8u5z8V0ZqDED7jp+RdJAoY/wFFg8oyxiFRGhLDCQ Iq21/wZSUW3y+sv9+ziTrWKGddmM7nHD2w+l9Wq4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Ahern , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 196/230] ndisc: use RCU protection in ndisc_alloc_skb() Date: Wed, 19 Feb 2025 09:28:33 +0100 Message-ID: <20250219082609.364657813@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250219082601.683263930@linuxfoundation.org> References: <20250219082601.683263930@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 628e6d18930bbd21f2d4562228afe27694f66da9 ] ndisc_alloc_skb() can be called without RTNL or RCU being held. Add RCU protection to avoid possible UAF. Fixes: de09334b9326 ("ndisc: Introduce ndisc_alloc_skb() helper.") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250207135841.1948589-3-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/ndisc.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 264b10a947577..90f8aa2d7af2e 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -418,15 +418,11 @@ static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, { int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; - struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; struct sk_buff *skb; skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); - if (!skb) { - ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", - __func__); + if (!skb) return NULL; - } skb->protocol = htons(ETH_P_IPV6); skb->dev = dev; @@ -437,7 +433,9 @@ static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, /* Manually assign socket ownership as we avoid calling * sock_alloc_send_pskb() to bypass wmem buffer limits */ - skb_set_owner_w(skb, sk); + rcu_read_lock(); + skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk); + rcu_read_unlock(); return skb; } -- 2.39.5