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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AD46CECE58A for ; Tue, 1 Oct 2019 16:55:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84EDB21783 for ; Tue, 1 Oct 2019 16:55:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948948; bh=dNaNYjv6BMmvGTTI/w/4u5vdzACGMX2rD6+bZYlA/dc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ajRVyfCmnUAoG8GRHQuPqOjqsjggOmBZ3gdvhYavIKyG/OEnQT4w7BLRG1IAZBYRT SeA/p0UDu8D5UN4hweGYO3EcXNVgGtX/g/6bPx/x6UP6DKoGH/X8DtOgZqLXkFjAHq wrgsI1SDR5pFvfPGcGe0q5mHD+5UviatwAqaDIYw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731950AbfJAQmY (ORCPT ); Tue, 1 Oct 2019 12:42:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:54238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731908AbfJAQmX (ORCPT ); Tue, 1 Oct 2019 12:42:23 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9922B21906; Tue, 1 Oct 2019 16:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948142; bh=dNaNYjv6BMmvGTTI/w/4u5vdzACGMX2rD6+bZYlA/dc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P9oenq4vod870e+3JfPCHbM0LrxWW98wR/yTUwr2gUNMUkSyZULqlo1y3ikjv3ioj AVSF6/zTTlZ0WVvEHpx7u+JguyyXuGV4Yrgc4ez53+oBXxyEA6JhMbDEYBjyLif1BE CWpKpMxLQrSKWGswgyyeRdUUtegR6wdfhNVX9Zd8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takeshi Misawa , syzbot+d9c8bf24e56416d7ce2c@syzkaller.appspotmail.com, Guillaume Nault , "David S . Miller" , Sasha Levin , linux-ppp@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 40/63] ppp: Fix memory leak in ppp_write Date: Tue, 1 Oct 2019 12:41:02 -0400 Message-Id: <20191001164125.15398-40-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164125.15398-1-sashal@kernel.org> References: <20191001164125.15398-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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: Sasha Levin --- drivers/net/ppp/ppp_generic.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index a30e41a560853..9a1b006904a7d 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1415,6 +1415,8 @@ static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) netif_wake_queue(ppp->dev); else netif_stop_queue(ppp->dev); + } else { + kfree_skb(skb); } ppp_xmit_unlock(ppp); } -- 2.20.1