From patchwork Tue Aug 6 09:41:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: He Zhe X-Patchwork-Id: 11078557 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A037114E5 for ; Tue, 6 Aug 2019 09:41:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8C224288DA for ; Tue, 6 Aug 2019 09:41:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 807D528961; Tue, 6 Aug 2019 09:41:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 13A86288DA for ; Tue, 6 Aug 2019 09:41:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732325AbfHFJlP (ORCPT ); Tue, 6 Aug 2019 05:41:15 -0400 Received: from mail1.windriver.com ([147.11.146.13]:63123 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730068AbfHFJlP (ORCPT ); Tue, 6 Aug 2019 05:41:15 -0400 Received: from ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) by mail1.windriver.com (8.15.2/8.15.1) with ESMTPS id x769f7SV000779 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Tue, 6 Aug 2019 02:41:07 -0700 (PDT) Received: from pek-lpg-core2.corp.ad.wrs.com (128.224.153.41) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.468.0; Tue, 6 Aug 2019 02:41:07 -0700 From: To: , , , , Subject: [PATCH] nfsd4: Fix kernel crash when reading proc file reply_cache_stats Date: Tue, 6 Aug 2019 17:41:04 +0800 Message-ID: <1565084464-248436-1-git-send-email-zhe.he@windriver.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: He Zhe reply_cache_stats uses wrong parameter as seq file private structure and thus causes the following kernel crash when users read /proc/fs/nfsd/reply_cache_stats BUG: kernel NULL pointer dereference, address: 00000000000001f9 PGD 0 P4D 0 Oops: 0000 [#3] SMP PTI CPU: 6 PID: 1502 Comm: cat Tainted: G D 5.3.0-rc3+ #1 Hardware name: Intel Corporation Broadwell Client platform/Basking Ridge, BIOS BDW-E2R1.86C.0118.R01.1503110618 03/11/2015 RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa520106fe08 EFLAGS: 00010246 RAX: 000000cfe1a77123 RBX: 0000000000000000 RCX: 0000000000291b46 RDX: 000000cf00000000 RSI: 0000000000000006 RDI: 0000000000291b28 RBP: ffffaa520106fe20 R08: 0000000000000006 R09: 000000cfe17e55dd R10: ffffa424e47c0000 R11: 000000000000030b R12: 0000000000000001 R13: ffffa424e5697000 R14: 0000000000000001 R15: ffffa424e5697000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Call Trace: seq_read+0x194/0x3e0 __vfs_read+0x1b/0x40 vfs_read+0x95/0x140 ksys_read+0x61/0xe0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f805728b861 Code: fe ff ff 50 48 8d 3d 86 b4 09 00 e8 79 e0 01 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 d9 19 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 48 83 ec 28 48 89 54 RSP: 002b:00007ffea1ce3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f805728b861 RDX: 0000000000020000 RSI: 00007f8057183000 RDI: 0000000000000003 RBP: 00007f8057183000 R08: 00007f8057182010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000559a60e8ff10 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 Modules linked in: CR2: 00000000000001f9 ---[ end trace 01613595153f0cba ]--- RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa52004b3e08 EFLAGS: 00010246 RAX: 0000002bab45a7c6 RBX: 0000000000000000 RCX: 0000000000291b4c RDX: 0000002b00000000 RSI: 0000000000000004 RDI: 0000000000291b28 RBP: ffffaa52004b3e20 R08: 0000000000000004 R09: 0000002bab1c8c7a R10: ffffa424e5500000 R11: 00000000000002a9 R12: 0000000000000001 R13: ffffa424e4475000 R14: 0000000000000001 R15: ffffa424e4475000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Killed Fixes: 3ba75830ce17 ("nfsd4: drc containerization") Signed-off-by: He Zhe --- fs/nfsd/nfscache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 26ad75a..96352ab 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -571,7 +571,7 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data) */ static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v) { - struct nfsd_net *nn = v; + struct nfsd_net *nn = m->private; seq_printf(m, "max entries: %u\n", nn->max_drc_entries); seq_printf(m, "num entries: %u\n",