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 D4651C10F14 for ; Thu, 3 Oct 2019 16:14:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A950721783 for ; Thu, 3 Oct 2019 16:14:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570119291; bh=yJTPNF/Co3hgq7+7x8NMQeGLOqXVJ4OSl9f4tPbFaTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=deeFUwcZN7OIEORI/usADp2y+GOszTOpkviFHiUnvqWZ1bVLCsmXDTIyXpDDuoYQc jX8vHNRFn56QKpEdyUp3XbLmwJb75Or84T3uvtQeqsEnSqYj8mYp4cqJEuSQXj6gwE LkRnyUezsrdUVFNtf+1HX5Dkeb91ASs/lO+O6RNg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388718AbfJCQOv (ORCPT ); Thu, 3 Oct 2019 12:14:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:38398 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388704AbfJCQOs (ORCPT ); Thu, 3 Oct 2019 12:14:48 -0400 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 E7873222C4; Thu, 3 Oct 2019 16:14:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570119287; bh=yJTPNF/Co3hgq7+7x8NMQeGLOqXVJ4OSl9f4tPbFaTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1QfMmvWsj6ECRdRFc+JE34FMIwab8HVqI4qLyj8mhKb1RWTw0PIfBm0bG4es51dFq mr/3yPAUouEkZ0Mrh2EvYjMN0UMQGxbBGmi7KXnuOksjbvVQ5EIb4JjUNYrTBFVXbY BYvXc/SkWtpL0dZuFNlfHhitrYj8apS9kU/5pNhE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takeshi Misawa , Guillaume Nault , "David S. Miller" , syzbot+d9c8bf24e56416d7ce2c@syzkaller.appspotmail.com Subject: [PATCH 4.19 010/211] ppp: Fix memory leak in ppp_write Date: Thu, 3 Oct 2019 17:51:16 +0200 Message-Id: <20191003154449.434454700@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154447.010950442@linuxfoundation.org> References: <20191003154447.010950442@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: Takeshi Misawa [ Upstream commit 4c247de564f1ff614d11b3bb5313fb70d7b9598b ] When ppp is closing, __ppp_xmit_process() failed to enqueue skb and skb allocated in ppp_write() is leaked. syzbot reported : BUG: memory leak unreferenced object 0xffff88812a17bc00 (size 224): comm "syz-executor673", pid 6952, jiffies 4294942888 (age 13.040s) 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: [<00000000d110fff9>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<00000000d110fff9>] slab_post_alloc_hook mm/slab.h:522 [inline] [<00000000d110fff9>] slab_alloc_node mm/slab.c:3262 [inline] [<00000000d110fff9>] kmem_cache_alloc_node+0x163/0x2f0 mm/slab.c:3574 [<000000002d616113>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:197 [<000000000167fc45>] alloc_skb include/linux/skbuff.h:1055 [inline] [<000000000167fc45>] ppp_write+0x48/0x120 drivers/net/ppp/ppp_generic.c:502 [<000000009ab42c0b>] __vfs_write+0x43/0xa0 fs/read_write.c:494 [<00000000086b2e22>] vfs_write fs/read_write.c:558 [inline] [<00000000086b2e22>] vfs_write+0xee/0x210 fs/read_write.c:542 [<00000000a2b70ef9>] ksys_write+0x7c/0x130 fs/read_write.c:611 [<00000000ce5e0fdd>] __do_sys_write fs/read_write.c:623 [inline] [<00000000ce5e0fdd>] __se_sys_write fs/read_write.c:620 [inline] [<00000000ce5e0fdd>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620 [<00000000d9d7b370>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296 [<0000000006e6d506>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fix this by freeing skb, if ppp is closing. Fixes: 6d066734e9f0 ("ppp: avoid loop in xmit recursion detection code") Reported-and-tested-by: syzbot+d9c8bf24e56416d7ce2c@syzkaller.appspotmail.com Signed-off-by: Takeshi Misawa Reviewed-by: Guillaume Nault Tested-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ppp/ppp_generic.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1419,6 +1419,8 @@ static void __ppp_xmit_process(struct pp netif_wake_queue(ppp->dev); else netif_stop_queue(ppp->dev); + } else { + kfree_skb(skb); } ppp_xmit_unlock(ppp); }