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 AEFB98BE5 for ; Mon, 19 Jun 2023 10:49:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BDA2C433C8; Mon, 19 Jun 2023 10:49:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687171762; bh=MS+RDxyshMG/5IO9RS3iraWPZfM1UETS5z4jCbnUr9w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KkmtGmleC+pZ5FL2MKbbuXYeqyuU+c7tIeUFW47W7IIJC+IsfBTYd82h94HVvd0nf 887FDAmd+r2Y8Mq5bnnrO6WB2ueTRd00+ou4yAB7OMm1OlEO0OdYtV8zR6VoTsielz PR9qm6OW35Ij2uq3LZTOf4OO/JbciOhBQaTFPHsA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fedor Pchelkin , Sabrina Dubroca , "David S. Miller" , Sasha Levin Subject: [PATCH 6.1 148/166] net: macsec: fix double free of percpu stats Date: Mon, 19 Jun 2023 12:30:25 +0200 Message-ID: <20230619102201.888804141@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230619102154.568541872@linuxfoundation.org> References: <20230619102154.568541872@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Fedor Pchelkin [ Upstream commit 0c0cf3db83f8c7c9bb141c2771a34043bcf952ef ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 038a787943927..983cabf9a0f67 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3981,17 +3981,15 @@ static int macsec_add_dev(struct net_device *dev, sci_t sci, u8 icv_len) return -ENOMEM; secy->tx_sc.stats = 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; - } secy->tx_sc.md_dst = 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; - } if (sci == MACSEC_UNDEF_SCI) sci = dev_to_sci(dev, MACSEC_PORT_ES); -- 2.39.2