From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B37BC2D0DB for ; Tue, 28 Jan 2020 13:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C6D82468A for ; Tue, 28 Jan 2020 13:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580219965; bh=+nPt4fGip0//XuMl2t2UICHr4ttdiN5OsI2+WOkv7Sg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=su6VBGsdayycrYuiG/hM2aPlFkV7q/0QS3U8NVuk6sQcbDXl0vJXyxnjoLkO+IgZe TyckRhyx6X35N2IK4uujxUg6GmXK3RoGUFj652spoaqIUb6Pq5h5FP3yxQjPGzD3+Q PNIy9cxcSQoegthkAKGhlTMm9uG7eI2Q8947fCX4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726294AbgA1N7Y (ORCPT ); Tue, 28 Jan 2020 08:59:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:44704 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726833AbgA1N7V (ORCPT ); Tue, 28 Jan 2020 08:59:21 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 09F062173E; Tue, 28 Jan 2020 13:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580219960; bh=+nPt4fGip0//XuMl2t2UICHr4ttdiN5OsI2+WOkv7Sg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eozuMrzAMi5F+jxFGEa0pFgllzoD4ZHWzqw6Ge/1MH6GdVhQ+BeoXYmD4f+SRww4f y/r6PgxaH012FEiBeHa5jr5zN0GdWpTJ82kOL663XHHHuL35FHCJkwIwuYM0Fyll1Y D/fAHRp+wB6VmHYaLljiTCOox4z2SpddugNJ8Zyg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ad8ca40ecd77896d51e2@syzkaller.appspotmail.com, David Miller , Lukas Bulwahn , Jouni Hogander Subject: [PATCH 4.14 13/46] net-sysfs: Fix reference count leak Date: Tue, 28 Jan 2020 14:57:47 +0100 Message-Id: <20200128135751.746247926@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135749.822297911@linuxfoundation.org> References: <20200128135749.822297911@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jouni Hogander [ Upstream commit cb626bf566eb4433318d35681286c494f04fedcc ] Netdev_register_kobject is calling device_initialize. In case of error reference taken by device_initialize is not given up. Drivers are supposed to call free_netdev in case of error. In non-error case the last reference is given up there and device release sequence is triggered. In error case this reference is kept and the release sequence is never started. Fix this by setting reg_state as NETREG_UNREGISTERED if registering fails. This is the rootcause for couple of memory leaks reported by Syzkaller: BUG: memory leak unreferenced object 0xffff8880675ca008 (size 256): comm "netdev_register", pid 281, jiffies 4294696663 (age 6.808s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000058ca4711>] kmem_cache_alloc_trace+0x167/0x280 [<000000002340019b>] device_add+0x882/0x1750 [<000000001d588c3a>] netdev_register_kobject+0x128/0x380 [<0000000011ef5535>] register_netdevice+0xa1b/0xf00 [<000000007fcf1c99>] __tun_chr_ioctl+0x20d5/0x3dd0 [<000000006a5b7b2b>] tun_chr_ioctl+0x2f/0x40 [<00000000f30f834a>] do_vfs_ioctl+0x1c7/0x1510 [<00000000fba062ea>] ksys_ioctl+0x99/0xb0 [<00000000b1c1b8d2>] __x64_sys_ioctl+0x78/0xb0 [<00000000984cabb9>] do_syscall_64+0x16f/0x580 [<000000000bde033d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<00000000e6ca2d9f>] 0xffffffffffffffff BUG: memory leak unreferenced object 0xffff8880668ba588 (size 8): comm "kobject_set_nam", pid 286, jiffies 4294725297 (age 9.871s) hex dump (first 8 bytes): 6e 72 30 00 cc be df 2b nr0....+ backtrace: [<00000000a322332a>] __kmalloc_track_caller+0x16e/0x290 [<00000000236fd26b>] kstrdup+0x3e/0x70 [<00000000dd4a2815>] kstrdup_const+0x3e/0x50 [<0000000049a377fc>] kvasprintf_const+0x10e/0x160 [<00000000627fc711>] kobject_set_name_vargs+0x5b/0x140 [<0000000019eeab06>] dev_set_name+0xc0/0xf0 [<0000000069cb12bc>] netdev_register_kobject+0xc8/0x320 [<00000000f2e83732>] register_netdevice+0xa1b/0xf00 [<000000009e1f57cc>] __tun_chr_ioctl+0x20d5/0x3dd0 [<000000009c560784>] tun_chr_ioctl+0x2f/0x40 [<000000000d759e02>] do_vfs_ioctl+0x1c7/0x1510 [<00000000351d7c31>] ksys_ioctl+0x99/0xb0 [<000000008390040a>] __x64_sys_ioctl+0x78/0xb0 [<0000000052d196b7>] do_syscall_64+0x16f/0x580 [<0000000019af9236>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<00000000bc384531>] 0xffffffffffffffff v3 -> v4: Set reg_state to NETREG_UNREGISTERED if registering fails v2 -> v3: * Replaced BUG_ON with WARN_ON in free_netdev and netdev_release v1 -> v2: * Relying on driver calling free_netdev rather than calling put_device directly in error path Reported-by: syzbot+ad8ca40ecd77896d51e2@syzkaller.appspotmail.com Cc: David Miller Cc: Greg Kroah-Hartman Cc: Lukas Bulwahn Signed-off-by: Jouni Hogander Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7667,8 +7667,10 @@ int register_netdevice(struct net_device goto err_uninit; ret = netdev_register_kobject(dev); - if (ret) + if (ret) { + dev->reg_state = NETREG_UNREGISTERED; goto err_uninit; + } dev->reg_state = NETREG_REGISTERED; __netdev_update_features(dev);