From patchwork Tue Sep 3 11:14:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Lingfeng X-Patchwork-Id: 13788528 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 536031A42AA; Tue, 3 Sep 2024 11:05:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725361505; cv=none; b=MVorOex3gxA36Kul81nTG+zs+dV+AzlcO51zTopEDVLQzmtQ0l36Sar4bxxSbA0FL/sY3P3jbvOKt363l3+M4SAr5JucGxWmIdYYALberFhMwVg3O3HjG15AAdUUSEV0BdSzjEcpi43Pntc5cT8s1JdKpVtsOgvgOLTEfqO4o1o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725361505; c=relaxed/simple; bh=hB6fcwq6XdKfTlxxS89U8hmHpeWw82yFyWLpkJ8m8B8=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=dcDg/vkp0KkO0Wl9TcmGZPXtKm953Tj6nK8M0a6R4KUBsoBtD4T0zglTNwK2KdzwYf7elVzH74Yb+7qiNNA8NPKtgoNBf01HF6iV283X++K3LU35caQ/YgIHBqvYFNvVr5n4EfQ1S9wEsb9wHfgr5AffjLlgHYCh5/mHB3VPK0g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4WyjM72jLBz20nDG; Tue, 3 Sep 2024 19:00:03 +0800 (CST) Received: from kwepemg500017.china.huawei.com (unknown [7.202.181.81]) by mail.maildlp.com (Postfix) with ESMTPS id 5ADC0140137; Tue, 3 Sep 2024 19:04:59 +0800 (CST) Received: from huawei.com (10.175.127.227) by kwepemg500017.china.huawei.com (7.202.181.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 3 Sep 2024 19:04:58 +0800 From: Li Lingfeng To: , , , , , CC: , , , , , , , Subject: [PATCH] nfsd: return -EINVAL when namelen is 0 Date: Tue, 3 Sep 2024 19:14:46 +0800 Message-ID: <20240903111446.659884-1-lilingfeng3@huawei.com> X-Mailer: git-send-email 2.31.1 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemg500017.china.huawei.com (7.202.181.81) When we have a corrupted main.sqlite in /var/lib/nfs/nfsdcld/, it may result in namelen being 0, which will cause memdup_user() to return ZERO_SIZE_PTR. When we access the name.data that has been assigned the value of ZERO_SIZE_PTR in nfs4_client_to_reclaim(), null pointer dereference is triggered. [ T1205] ================================================================== [ T1205] BUG: KASAN: null-ptr-deref in nfs4_client_to_reclaim+0xe9/0x260 [ T1205] Read of size 1 at addr 0000000000000010 by task nfsdcld/1205 [ T1205] [ T1205] CPU: 11 PID: 1205 Comm: nfsdcld Not tainted 5.10.0-00003-g2c1423731b8d #406 [ T1205] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 [ T1205] Call Trace: [ T1205] dump_stack+0x9a/0xd0 [ T1205] ? nfs4_client_to_reclaim+0xe9/0x260 [ T1205] __kasan_report.cold+0x34/0x84 [ T1205] ? nfs4_client_to_reclaim+0xe9/0x260 [ T1205] kasan_report+0x3a/0x50 [ T1205] nfs4_client_to_reclaim+0xe9/0x260 [ T1205] ? nfsd4_release_lockowner+0x410/0x410 [ T1205] cld_pipe_downcall+0x5ca/0x760 [ T1205] ? nfsd4_cld_tracking_exit+0x1d0/0x1d0 [ T1205] ? down_write_killable_nested+0x170/0x170 [ T1205] ? avc_policy_seqno+0x28/0x40 [ T1205] ? selinux_file_permission+0x1b4/0x1e0 [ T1205] rpc_pipe_write+0x84/0xb0 [ T1205] vfs_write+0x143/0x520 [ T1205] ksys_write+0xc9/0x170 [ T1205] ? __ia32_sys_read+0x50/0x50 [ T1205] ? ktime_get_coarse_real_ts64+0xfe/0x110 [ T1205] ? ktime_get_coarse_real_ts64+0xa2/0x110 [ T1205] do_syscall_64+0x33/0x40 [ T1205] entry_SYSCALL_64_after_hwframe+0x67/0xd1 [ T1205] RIP: 0033:0x7fdbdb761bc7 [ T1205] Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 514 [ T1205] RSP: 002b:00007fff8c4b7248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ T1205] RAX: ffffffffffffffda RBX: 000000000000042b RCX: 00007fdbdb761bc7 [ T1205] RDX: 000000000000042b RSI: 00007fff8c4b75f0 RDI: 0000000000000008 [ T1205] RBP: 00007fdbdb761bb0 R08: 0000000000000000 R09: 0000000000000001 [ T1205] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000042b [ T1205] R13: 0000000000000008 R14: 00007fff8c4b75f0 R15: 0000000000000000 [ T1205] ================================================================== Fix it by checking namelen. Signed-off-by: Li Lingfeng Reviewed-by: Jeff Layton --- fs/nfsd/nfs4recover.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 67d8673a9391..69a3a84e159e 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -809,6 +809,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg, ci = &cmsg->cm_u.cm_clntinfo; if (get_user(namelen, &ci->cc_name.cn_len)) return -EFAULT; + if (!namelen) { + dprintk("%s: namelen should not be zero", __func__); + return -EINVAL; + } name.data = memdup_user(&ci->cc_name.cn_id, namelen); if (IS_ERR(name.data)) return PTR_ERR(name.data); @@ -831,6 +835,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg, cnm = &cmsg->cm_u.cm_name; if (get_user(namelen, &cnm->cn_len)) return -EFAULT; + if (!namelen) { + dprintk("%s: namelen should not be zero", __func__); + return -EINVAL; + } name.data = memdup_user(&cnm->cn_id, namelen); if (IS_ERR(name.data)) return PTR_ERR(name.data);