From nobody Mon Feb 9 00:26:17 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39C9BEB64D7 for ; Tue, 13 Jun 2023 19:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240019AbjFMTXS (ORCPT ); Tue, 13 Jun 2023 15:23:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229504AbjFMTXR (ORCPT ); Tue, 13 Jun 2023 15:23:17 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 352D01A5; Tue, 13 Jun 2023 12:23:14 -0700 (PDT) Received: from fpc.intra.ispras.ru (unknown [10.10.165.7]) by mail.ispras.ru (Postfix) with ESMTPSA id 4AFEC40737DA; Tue, 13 Jun 2023 19:23:09 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 4AFEC40737DA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1686684189; bh=hIRs6Uzx3zjkKCTmplY/Pi+dHaV4Bk/epLmdjrJuCpU=; h=From:To:Cc:Subject:Date:From; b=gk5PMbPcjnyrxDmuuKVB1Jfl6MY4re3uzov615Wm4y+5VHIIZjhshadNqXpi2PaQS qgNE+00grlAlcoepwp3VpOZgku5iOaibXnSIX1FOZ8sAP+BuxoSuvW7PMWHaV2/GRj WtvS7APzt8bZZ8lUjigxkcDuaK9WBi2l9O/mv5AA= From: Fedor Pchelkin To: "David S. Miller" Cc: Fedor Pchelkin , Sabrina Dubroca , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Raed Salem , Lior Nahmanson , Saeed Mahameed , Hannes Frederic Sowa , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexey Khoroshilov , lvc-project@linuxtesting.org Subject: [PATCH] net: macsec: fix double free of percpu stats Date: Tue, 13 Jun 2023 22:22:20 +0300 Message-Id: <20230613192220.159407-1-pchelkin@ispras.ru> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Inside macsec_add_dev() we free percpu macsec->secy.tx_sc.stats and macsec->stats on some of the memory allocation failure paths. However, the net_device is already registered to that moment: in macsec_newlink(), just before calling macsec_add_dev(). This means that during unregister process its priv_destructor - macsec_free_netdev() - will be called and will free the stats again. Remove freeing percpu stats inside macsec_add_dev() because macsec_free_netdev() will correctly free the already allocated ones. The pointers to unallocated stats stay NULL, and free_percpu() treats that correctly. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 0a28bfd4971f ("net/macsec: Add MACsec skb_metadata_dst Tx Data path = support") Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver") Signed-off-by: Fedor Pchelkin Reviewed-by: Sabrina Dubroca --- drivers/net/macsec.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 3427993f94f7..984dfa5d6c11 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3997,17 +3997,15 @@ static int macsec_add_dev(struct net_device *dev, s= ci_t sci, u8 icv_len) return -ENOMEM; =20 secy->tx_sc.stats =3D netdev_alloc_pcpu_stats(struct pcpu_tx_sc_stats); - if (!secy->tx_sc.stats) { - free_percpu(macsec->stats); + if (!secy->tx_sc.stats) return -ENOMEM; - } =20 secy->tx_sc.md_dst =3D metadata_dst_alloc(0, METADATA_MACSEC, GFP_KERNEL); - if (!secy->tx_sc.md_dst) { - free_percpu(secy->tx_sc.stats); - free_percpu(macsec->stats); + if (!secy->tx_sc.md_dst) + /* macsec and secy percpu stats will be freed when unregistering + * net_device in macsec_free_netdev() + */ return -ENOMEM; - } =20 if (sci =3D=3D MACSEC_UNDEF_SCI) sci =3D dev_to_sci(dev, MACSEC_PORT_ES); --=20 2.34.1