From patchwork Mon Jun 21 16:15:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 465117 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 8262CC48BC2 for ; Mon, 21 Jun 2021 16:20:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A11F61374 for ; Mon, 21 Jun 2021 16:20:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230526AbhFUQWS (ORCPT ); Mon, 21 Jun 2021 12:22:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:42214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231697AbhFUQVO (ORCPT ); Mon, 21 Jun 2021 12:21:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0B8D461351; Mon, 21 Jun 2021 16:18:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624292336; bh=RFB042bcX/DPn83t5Dgqy/pme1S1QtyqarEQjOxVpng=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jASoRYjt+MmyCMiMeAG4zVlFjU2ycDDIiy7cZnezZG4c0x4uPRAOlbZYCNj41GblK gc5YtC1uX7mozivPafLVCKvLDswgB8ADYID3tp7guIbX/+wDdi0FFdi1Xm4LnGnPea sAxtE366Xz6jtqjd5ra6F6Kzq1oISZhpK9E1HluA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Skripkin , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 36/90] net: hamradio: fix memory leak in mkiss_close Date: Mon, 21 Jun 2021 18:15:11 +0200 Message-Id: <20210621154905.348731123@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154904.159672728@linuxfoundation.org> References: <20210621154904.159672728@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pavel Skripkin [ Upstream commit 7edcc682301492380fbdd604b4516af5ae667a13 ] My local syzbot instance hit memory leak in mkiss_open()[1]. The problem was in missing free_netdev() in mkiss_close(). In mkiss_open() netdevice is allocated and then registered, but in mkiss_close() netdevice was only unregistered, but not freed. Fail log: BUG: memory leak unreferenced object 0xffff8880281ba000 (size 4096): comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s) hex dump (first 32 bytes): 61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00 ax0............. 00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00 .'.*............ backtrace: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x98/0xe80 [] mkiss_open+0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] entry_SYSCALL_64_after_hwframe+0x44/0xae BUG: memory leak unreferenced object 0xffff8880141a9a00 (size 96): comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s) hex dump (first 32 bytes): e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff ...(.......(.... 98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00 .....@.......... backtrace: [] __hw_addr_create_ex+0x5b/0x310 [] __hw_addr_add_ex+0x1f8/0x2b0 [] dev_addr_init+0x10b/0x1f0 [] alloc_netdev_mqs+0x13b/0xe80 [] mkiss_open+0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] entry_SYSCALL_64_after_hwframe+0x44/0xae BUG: memory leak unreferenced object 0xffff8880219bfc00 (size 512): comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s) hex dump (first 32 bytes): 00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ff ...(............ 80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x777/0xe80 [] mkiss_open+0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] entry_SYSCALL_64_after_hwframe+0x44/0xae BUG: memory leak unreferenced object 0xffff888029b2b200 (size 256): comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s) 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: [] kvmalloc_node+0x61/0xf0 [] alloc_netdev_mqs+0x912/0xe80 [] mkiss_open+0xb2/0x6f0 [1] [] tty_ldisc_open+0x9b/0x110 [] tty_set_ldisc+0x2e8/0x670 [] tty_ioctl+0xda3/0x1440 [] __x64_sys_ioctl+0x193/0x200 [] do_syscall_64+0x3a/0xb0 [] entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: 815f62bf7427 ("[PATCH] SMP rewrite of mkiss") Signed-off-by: Pavel Skripkin Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/hamradio/mkiss.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c index deef14215110..352f9e75954c 100644 --- a/drivers/net/hamradio/mkiss.c +++ b/drivers/net/hamradio/mkiss.c @@ -800,6 +800,7 @@ static void mkiss_close(struct tty_struct *tty) ax->tty = NULL; unregister_netdev(ax->dev); + free_netdev(ax->dev); } /* Perform I/O control on an active ax25 channel. */