Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCF38C433FE for ; Mon, 20 Dec 2021 14:47:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237412AbhLTOrZ (ORCPT ); Mon, 20 Dec 2021 09:47:25 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:51476 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236701AbhLTOpB (ORCPT ); Mon, 20 Dec 2021 09:45:01 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 95DA1B80EE3; Mon, 20 Dec 2021 14:45:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA43AC36AE7; Mon, 20 Dec 2021 14:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640011499; bh=xnaOqn3VbXZVWzmSHo+RGj/aAF5GZ6OX2q5+FRPfOo8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dCG2tbA+8K9C0MHV+XTwCVom/FBLCqYOzodsfB/V2pEDI/uhiaVSz0/0jMrPAM66o lpESGOL5sTD3C0BdfgVPqqWuh9nX7f8aAK3dZ0E2DyTQmn70Txb1cLrQmowdt7EBMe GXtcFy4hHVTcamQYC0fkkInjKHHEpKzxINX1Dv7c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 43/71] sit: do not call ipip6_dev_free() from sit_init_net() Date: Mon, 20 Dec 2021 15:34:32 +0100 Message-Id: <20211220143027.132613208@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211220143025.683747691@linuxfoundation.org> References: <20211220143025.683747691@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit e28587cc491ef0f3c51258fdc87fbc386b1d4c59 ] ipip6_dev_free is sit dev->priv_destructor, already called by register_netdevice() if something goes wrong. Alternative would be to make ipip6_dev_free() robust against multiple invocations, but other drivers do not implement this strategy. syzbot reported: dst_release underflow WARNING: CPU: 0 PID: 5059 at net/core/dst.c:173 dst_release+0xd8/0xe0 net/core/dst.c:173 Modules linked in: CPU: 1 PID: 5059 Comm: syz-executor.4 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dst_release+0xd8/0xe0 net/core/dst.c:173 Code: 4c 89 f2 89 d9 31 c0 5b 41 5e 5d e9 da d5 44 f9 e8 1d 90 5f f9 c6 05 87 48 c6 05 01 48 c7 c7 80 44 99 8b 31 c0 e8 e8 67 29 f9 <0f> 0b eb 85 0f 1f 40 00 53 48 89 fb e8 f7 8f 5f f9 48 83 c3 a8 48 RSP: 0018:ffffc9000aa5faa0 EFLAGS: 00010246 RAX: d6894a925dd15a00 RBX: 00000000ffffffff RCX: 0000000000040000 RDX: ffffc90005e19000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000000 R08: ffffffff816a1f42 R09: ffffed1017344f2c R10: ffffed1017344f2c R11: 0000000000000000 R12: 0000607f462b1358 R13: 1ffffffff1bfd305 R14: ffffe8ffffcb1358 R15: dffffc0000000000 FS: 00007f66c71a2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f88aaed5058 CR3: 0000000023e0f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dst_cache_destroy+0x107/0x1e0 net/core/dst_cache.c:160 ipip6_dev_free net/ipv6/sit.c:1414 [inline] sit_init_net+0x229/0x550 net/ipv6/sit.c:1936 ops_init+0x313/0x430 net/core/net_namespace.c:140 setup_net+0x35b/0x9d0 net/core/net_namespace.c:326 copy_net_ns+0x359/0x5c0 net/core/net_namespace.c:470 create_new_namespaces+0x4ce/0xa00 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57d/0xb50 kernel/fork.c:3075 __do_sys_unshare kernel/fork.c:3146 [inline] __se_sys_unshare kernel/fork.c:3144 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3144 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f66c882ce99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f66c71a2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f66c893ff60 RCX: 00007f66c882ce99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000048040200 RBP: 00007f66c8886ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff6634832f R14: 00007f66c71a2300 R15: 0000000000022000 Fixes: cf124db566e6 ("net: Fix inconsistent teardown and release of private netdev state.") Signed-off-by: Eric Dumazet Reported-by: syzbot Link: https://lore.kernel.org/r/20211216111741.1387540-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/sit.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 7f9cae4c49e7e..16e75a996b749 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1876,7 +1876,6 @@ static int __net_init sit_init_net(struct net *net) return 0; err_reg_dev: - ipip6_dev_free(sitn->fb_tunnel_dev); free_netdev(sitn->fb_tunnel_dev); err_alloc_dev: return err; -- 2.33.0