From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-9106.amazon.com (smtp-fw-9106.amazon.com [207.171.188.206]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5843C15380A for ; Wed, 27 Mar 2024 21:27:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.171.188.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711574847; cv=none; b=NST2t+q5V14wBqShH81XChfiHSPqvCtYcTORTuwD+S6GC3F/ZfICb2nkUn3O7fvrMNSnJ6hcTrluC4YDOul2KkJiNaZL1dj1VrVv7OdzILh6Obd3az6i187Ivo4HkqJH5JYek7hIVqOkf1+ExNHTADG2VR1p46Ro2WFV7kTm3IM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711574847; c=relaxed/simple; bh=C/j887tj4udL31AqIBUo1u2n1jRjMfXxwuefa6/BV/Q=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=nnqPghzm5VuFCCqrehkCUPzRnJ0mqaz2bv56rteCa/ydB0UFbuJFhFO0uDs0tzFqYnbrjWOtp4onc8NRaTC+AIR0tSz/Rb6W9iVUD1/qpITxomKvKSnPQ+AflgA1yDTd8nRciU0dHkRkIIuuSThMcQkpVp49C1yW6xM9yhxSFd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.jp; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=YYLepP/q; arc=none smtp.client-ip=207.171.188.206 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="YYLepP/q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1711574845; x=1743110845; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=yB5eVj7R3bMwQK8+bTiRV53GmBh4sRlY3VaCYfMCADw=; b=YYLepP/qPZfTtWJKlGEQpGkrxjfOFIjWiHQfrLnEsXV9Ds3s8pZ5C7X1 +SWjM1hWqds5wSno5XAsZ16gk2GB+Vib/MgZkbtPuUeqEQOfZ3bMFG0h2 hgYiGHRQoppuL3+rtIgA/kEaOZiulJAwejJoiwXK3lSv5Vkmg9oE0yJNa Y=; X-IronPort-AV: E=Sophos;i="6.07,160,1708387200"; d="scan'208";a="714304046" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.25.36.210]) by smtp-border-fw-9106.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2024 21:27:20 +0000 Received: from EX19MTAUWC001.ant.amazon.com [10.0.7.35:55894] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.20.22:2525] with esmtp (Farcaster) id 7e1fe94b-f74a-48cc-b546-2d73f361e499; Wed, 27 Mar 2024 21:27:20 +0000 (UTC) X-Farcaster-Flow-ID: 7e1fe94b-f74a-48cc-b546-2d73f361e499 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWC001.ant.amazon.com (10.250.64.174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Wed, 27 Mar 2024 21:27:19 +0000 Received: from 88665a182662.ant.amazon.com (10.106.100.29) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.28; Wed, 27 Mar 2024 21:27:17 +0000 From: Kuniyuki Iwashima To: Trond Myklebust , Anna Schumaker CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , syzkaller Subject: [PATCH v1] nfs: Handle error of rpc_proc_register() in nfs_net_init(). Date: Wed, 27 Mar 2024 14:27:06 -0700 Message-ID: <20240327212706.27691-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D045UWA004.ant.amazon.com (10.13.139.91) To EX19D004ANA001.ant.amazon.com (10.37.240.138) syzkaller reported a warning [0] triggered while destroying immature netns. rpc_proc_register() was called in init_nfs_fs(), but its error has been ignored since at least the initial commit 1da177e4c3f4 ("Linux-2.6.12-rc2"). Recently, commit d47151b79e32 ("nfs: expose /proc/net/sunrpc/nfs in net namespaces") converted the procfs to per-netns and made the problem more visible. Even when rpc_proc_register() fails, nfs_net_init() could succeed, and thus nfs_net_exit() will be called while destroying the netns. Then, remove_proc_entry() will be called for non-existing proc directory and trigger the warning below. Let's handle the error of rpc_proc_register() properly in nfs_net_init(). [0]: name 'nfs' WARNING: CPU: 1 PID: 1710 at fs/proc/generic.c:711 remove_proc_entry+0x1bb/0x2d0 fs/proc/generic.c:711 Modules linked in: CPU: 1 PID: 1710 Comm: syz-executor.2 Not tainted 6.8.0-12822-gcd51db110a7e #12 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:remove_proc_entry+0x1bb/0x2d0 fs/proc/generic.c:711 Code: 41 5d 41 5e c3 e8 85 09 b5 ff 48 c7 c7 88 58 64 86 e8 09 0e 71 02 e8 74 09 b5 ff 4c 89 e6 48 c7 c7 de 1b 80 84 e8 c5 ad 97 ff <0f> 0b eb b1 e8 5c 09 b5 ff 48 c7 c7 88 58 64 86 e8 e0 0d 71 02 eb RSP: 0018:ffffc9000c6d7ce0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8880422b8b00 RCX: ffffffff8110503c RDX: ffff888030652f00 RSI: ffffffff81105045 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff81bb62cb R12: ffffffff84807ffc R13: ffff88804ad6fcc0 R14: ffffffff84807ffc R15: ffffffff85741ff8 FS: 00007f30cfba8640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff51afe8000 CR3: 000000005a60a005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: rpc_proc_unregister+0x64/0x70 net/sunrpc/stats.c:310 nfs_net_exit+0x1c/0x30 fs/nfs/inode.c:2438 ops_exit_list+0x62/0xb0 net/core/net_namespace.c:170 setup_net+0x46c/0x660 net/core/net_namespace.c:372 copy_net_ns+0x244/0x590 net/core/net_namespace.c:505 create_new_namespaces+0x2ed/0x770 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xae/0x160 kernel/nsproxy.c:228 ksys_unshare+0x342/0x760 kernel/fork.c:3322 __do_sys_unshare kernel/fork.c:3393 [inline] __se_sys_unshare kernel/fork.c:3391 [inline] __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3391 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x46/0x4e RIP: 0033:0x7f30d0febe5d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007f30cfba7cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007f30d0febe5d RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c020600 RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007f30d104c530 R15: 0000000000000000 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzkaller Signed-off-by: Kuniyuki Iwashima --- fs/nfs/inode.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index c709c296ea9a..dd224ba196ef 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -2427,9 +2427,16 @@ EXPORT_SYMBOL_GPL(nfs_net_id); static int nfs_net_init(struct net *net) { struct nfs_net *nn = net_generic(net, nfs_net_id); + int err; nfs_clients_init(net); - rpc_proc_register(net, &nn->rpcstats); + + err = rpc_proc_register(net, &nn->rpcstats); + if (err) { + nfs_clients_exit(net); + return err; + } + return nfs_fs_proc_net_init(net); } -- 2.30.2