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[23.128.96.18]) by mx.google.com with ESMTP id d6si17868116ilm.75.2021.06.28.12.34.56; Mon, 28 Jun 2021 12:35:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=Ohjn+XDa; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236055AbhF1OqM (ORCPT + 99 others); Mon, 28 Jun 2021 10:46:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:43982 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235338AbhF1OfW (ORCPT ); Mon, 28 Jun 2021 10:35:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7EB3061C9E; Mon, 28 Jun 2021 14:30:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624890630; bh=ZhudtaCtWlly0EAeh0317uFcm9vgXLNyBmrC/gLT+7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ohjn+XDavNuUz/NpuFRQIR4dm2OtG+nJlDsadBgLs+bSUS0+mA/wLc4LpBZ/nE/4C hyJd8SvEXuZQ2LqzJbvrQCS/ac3BPNruRYHlVsNxVil4a0cd8dKsc0nSAnOtp1LTkM /8d2jLiadHc/oUAF1qGTUSwoUtC/pIKqcBEpMDqo77rXPg8FwWaUISDXR/2IkRPrbA y8Oq/rF7EF/qJxmGfwYLu71DpgmD+XZtQUNoTmHsjt7Cw0YULDYg9eFmlQXPLijsEY n4Uneqf409IyUgNps3RW/IlZfyZOrQgB1CDRBIEv6/LDUPHjepaUqP2t4TPuQ8xvbi h+2cfVxBVURdQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Pavel Skripkin , syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com, "David S . Miller" , Sasha Levin Subject: [PATCH 5.4 27/71] net: caif: fix memory leak in ldisc_open Date: Mon, 28 Jun 2021 10:29:20 -0400 Message-Id: <20210628143004.32596-28-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628143004.32596-1-sashal@kernel.org> References: <20210628143004.32596-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.4.129-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.4.129-rc1 X-KernelTest-Deadline: 2021-06-30T14:29+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit 58af3d3d54e87bfc1f936e16c04ade3369d34011 ] Syzbot reported memory leak in tty_init_dev(). The problem was in unputted tty in ldisc_open() static int ldisc_open(struct tty_struct *tty) { ... ser->tty = tty_kref_get(tty); ... result = register_netdevice(dev); if (result) { rtnl_unlock(); free_netdev(dev); return -ENODEV; } ... } Ser pointer is netdev private_data, so after free_netdev() this pointer goes away with unputted tty reference. So, fix it by adding tty_kref_put() before freeing netdev. Reported-and-tested-by: syzbot+f303e045423e617d2cad@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/caif/caif_serial.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 0f2bee59a82b..0bc7f6518fb3 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -351,6 +351,7 @@ static int ldisc_open(struct tty_struct *tty) rtnl_lock(); result = register_netdevice(dev); if (result) { + tty_kref_put(tty); rtnl_unlock(); free_netdev(dev); return -ENODEV; -- 2.30.2