Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932090Ab3DCSYN (ORCPT ); Wed, 3 Apr 2013 14:24:13 -0400 Received: from fieldses.org ([174.143.236.118]:41897 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762912Ab3DCSYL (ORCPT ); Wed, 3 Apr 2013 14:24:11 -0400 Date: Wed, 3 Apr 2013 14:24:10 -0400 From: "J. Bruce Fields" To: Takashi Iwai Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nfsd4: Fix NULL dereference in legacy_recdir_name_error() Message-ID: <20130403182410.GC6044@fieldses.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6206 Lines: 124 On Wed, Apr 03, 2013 at 06:27:26PM +0200, Takashi Iwai wrote: > The recent rewrite of NFSv4 recovery client tracking options per net > (commit 9a9c6478) introduced Oops when it faces an error for recdir > generation. Thanks. Looks like that could hit a lot of people actually, so I'll pass that along for 3.9 soon.--b. > > NFSD: unable to generate recoverydir name (-2). > NFSD: disabling legacy clientid tracking. Reboot recovery will not function correctly! > BUG: unable to handle kernel NULL pointer dereference at 00000000000007a8 > IP: [] nfsd4_client_tracking_exit+0x17/0x70 [nfsd] > PGD 0 > Oops: 0000 [#1] PREEMPT SMP > Modules linked in: nfsd fuse nfsv3 nfs_acl nfsv4 auth_rpcgss nfs lockd sunrpc cpufreq_conservative cpufreq_userspace cpufreq_powersave snd_hda_codec_hdmi snd_hda_codec_realtek intel_powerclamp acpi_cpufreq mperf coretemp ghash_clmulni_intel aesni_intel kvm_intel snd_hda_intel ablk_helper snd_hda_codec snd_hwdep kvm snd_pcm cryptd lrw aes_x86_64 snd_timer xts gf128mul e1000e snd sr_mod iTCO_wdt microcode cdrom usb_storage dcdbas iTCO_vendor_support i2c_i801 cdc_acm sg ptp lpc_ich mei soundcore pps_core mfd_core snd_page_alloc pciehp pci_hotplug autofs4 btrfs raid6_pq zlib_deflate xor libcrc32c i915 crc32c_intel drm_kms_helper drm xhci_hcd i2c_algo_bit thermal button video processor thermal_sys scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh > CPU 1 > Pid: 19567, comm: nfsd Not tainted 3.9.0-rc5-test+ #3 Dell Inc. OptiPlex 9010/0M9KCM > RIP: 0010:[] [] nfsd4_client_tracking_exit+0x17/0x70 [nfsd] > RSP: 0018:ffff880181099c28 EFLAGS: 00010202 > RAX: ffff8801810900c0 RBX: 0000000000000004 RCX: 0000000000000006 > RDX: 0000000000000007 RSI: 0000000000000046 RDI: 0000000000000000 > RBP: ffff880181099c38 R08: 000000000000000a R09: 000000000000039f > R10: 0000000000000000 R11: 000000000000039e R12: 0000000000000000 > R13: ffffffff81a87280 R14: ffff88014c819220 R15: ffff88020b75d200 > FS: 0000000000000000(0000) GS:ffff88021e240000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000000007a8 CR3: 0000000001a0d000 CR4: 00000000001407e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process nfsd (pid: 19567, threadinfo ffff880181098000, task ffff8801810900c0) > Stack: > 00000000fffffffe ffff88020b75d200 ffff880181099c58 ffffffffa060c75c > ffffffff81a87280 ffff880002ba7000 ffff880181099cc8 ffffffffa060cb37 > ffff880181099d20 ffff88014c819220 0000000000000001 ffff88020b75d200 > Call Trace: > [] legacy_recdir_name_error+0x3c/0x40 [nfsd] > [] nfsd4_create_clid_dir+0xe7/0x200 [nfsd] > [] ? nfs4_preprocess_seqid_op+0x63/0x160 [nfsd] > [] nfsd4_client_record_create+0x5f/0x80 [nfsd] > [] nfsd4_open_confirm+0x12f/0x1b0 [nfsd] > [] nfsd4_proc_compound+0x55f/0x770 [nfsd] > [] nfsd_dispatch+0xdd/0x220 [nfsd] > [] svc_process_common+0x328/0x6d0 [sunrpc] > [] svc_process+0x10c/0x160 [sunrpc] > [] nfsd+0xbf/0x130 [nfsd] > [] ? nfsd_destroy+0x90/0x90 [nfsd] > [] kthread+0xbb/0xc0 > [] ? kthread_create_on_node+0x130/0x130 > [] ret_from_fork+0x7c/0xb0 > [] ? kthread_create_on_node+0x130/0x130 > Code: e0 49 8b 84 24 48 01 00 00 e9 25 ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 41 54 49 89 fc 53 8b 1d 44 b4 00 00 e8 bb a9 a5 e0 85 db <49> 8b 84 24 a8 07 00 00 74 43 3b 18 77 3f 83 eb 01 48 63 db 48 > RIP [] nfsd4_client_tracking_exit+0x17/0x70 [nfsd] > RSP > CR2: 00000000000007a8 > ---[ end trace 5dd4307598e98cef ]--- > > This patch fixes it by passing the proper net instance instead of > NULL. > > Signed-off-by: Takashi Iwai > Cc: [v3.8+] > --- > fs/nfsd/nfs4recover.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c > index 899ca26..ae0d5c9 100644 > --- a/fs/nfsd/nfs4recover.c > +++ b/fs/nfsd/nfs4recover.c > @@ -146,7 +146,7 @@ out_no_tfm: > * then disable recovery tracking. > */ > static void > -legacy_recdir_name_error(int error) > +legacy_recdir_name_error(struct net *net, int error) > { > printk(KERN_ERR "NFSD: unable to generate recoverydir " > "name (%d).\n", error); > @@ -160,8 +160,7 @@ legacy_recdir_name_error(int error) > printk(KERN_ERR "NFSD: disabling legacy clientid tracking. " > "Reboot recovery will not function correctly!\n"); > > - /* the argument is ignored by the legacy exit function */ > - nfsd4_client_tracking_exit(NULL); > + nfsd4_client_tracking_exit(net); > } > } > > @@ -184,7 +183,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp) > > status = nfs4_make_rec_clidname(dname, &clp->cl_name); > if (status) > - return legacy_recdir_name_error(status); > + return legacy_recdir_name_error(clp->net, status); > > status = nfs4_save_creds(&original_cred); > if (status < 0) > @@ -341,7 +340,7 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp) > > status = nfs4_make_rec_clidname(dname, &clp->cl_name); > if (status) > - return legacy_recdir_name_error(status); > + return legacy_recdir_name_error(clp->net, status); > > status = mnt_want_write_file(nn->rec_file); > if (status) > @@ -601,7 +600,7 @@ nfsd4_check_legacy_client(struct nfs4_client *clp) > > status = nfs4_make_rec_clidname(dname, &clp->cl_name); > if (status) { > - legacy_recdir_name_error(status); > + legacy_recdir_name_error(clp->net, status); > return status; > } > > -- > 1.8.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/