From 36d3e3dcc93f1d3f70916ace76d94267b8948a2a Mon Sep 17 00:00:00 2001 From: Peng Tao Date: Tue, 8 Jul 2014 06:21:10 +0800 Subject: [PATCH] nfs: set hostname when creating nfsv3 ds connection lockd assumes hostname exists otherwise kernel oops. It can be reproduced by following steps: 1. mount flexfile MDS 2. write some files 3. mount DS via nfsv3 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] strlen+0x2/0x20 PGD 0 Oops: 0000 [#1] SMP Modules linked in: nfsd(F) nfs_layout_flexfiles(F) rpcsec_gss_krb5(F) auth_rpcgss(F) nfsv4(F) dns_resolver(F) nfsv3(F) nfs_acl(F) nfs(F) lockd(F) sunrpc(F) fscache(F) ebtable_nat(F) nf_conntrack_netbios_ns(F) nf_conntrack_broadcast(F) ipt_MASQUERADE(F) ip6table_nat(F) nf_nat_ipv6(F) ip6table_mangle(F) ip6t_REJECT(F) nf_conntrack_ipv6(F) nf_defrag_ipv6(F) iptable_nat(F) nf_nat_ipv4(F) nf_nat(F) iptable_mangle(F) nf_conntrack_ipv4(F) nf_defrag_ipv4(F) xt_conntrack(F) nf_conntrack(F) ebtable_filter(F) ebtables(F) ip6table_filter(F) ip6_tables(F) bnep(F) snd_ens1371(F) snd_rawmidi(F) snd_ac97_codec(F) btusb(F) ac97_bus(F) snd_seq(F) snd_seq_device(F) snd_pcm(F) ppdev(F) bluetooth(F) 6lowpan_iphc(F) rfkill(F) vmw_balloon(F) snd_timer(F) snd(F) soundcore(F) gameport(F) i2c_piix4(F) e1000(F) vmw_vmci(F) parport_pc(F) parport(F) shpchp(F) uinput(F) xfs(F) libcrc32c(F) vmwgfx(F) ttm(F) drm(F) mptspi(F) scsi_transport_spi(F) mptscsih(F) mptbase(F) i2c_core(F) CPU: 0 PID: 10397 Comm: mount.nfs Tainted: GF 3.14.7-100.pd_client.001.fc16.x86_64 #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 task: ffff880008942600 ti: ffff880007990000 task.ti: ffff880007990000 RIP: 0010:[] [] strlen+0x2/0x20 RSP: 0018:ffff880007991aa0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880038d39c20 RCX: 0000000000000004 RDX: 0000000000000006 RSI: 0000000000000010 RDI: 0000000000000000 RBP: ffff880007991b38 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000014600 R11: 0000000000000400 R12: ffffffff81cc8580 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000004 FS: 00007f90cd2ef880(0000) GS:ffff88003f600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000001710000 CR4: 00000000001407f0 Stack: ffffffffa045f52c ffff880001782230 ffff880004141e28 0006880007991ac8 ffffffff816dc14b ffff880000000000 ffff880038d39c20 0000000000000010 0000000481cc0006 0000000000000000 ffffffffa0410be8 000000000000c014 Call Trace: [] ? nlmclnt_lookup_host+0x4c/0x2c0 [lockd] [] ? _raw_spin_unlock_bh+0x1b/0x20 [] ? svc_destroy+0xb8/0x140 [sunrpc] [] nlmclnt_init+0x53/0xc0 [lockd] [] ? nfs_get_client+0x1cc/0x340 [nfs] [] nfs_start_lockd+0xa7/0xd0 [nfs] [] nfs_create_server+0x181/0x5c0 [nfs] [] nfs3_create_server+0x13/0x30 [nfsv3] [] nfs_try_mount+0x21c/0x300 [nfs] [] ? __kmalloc_track_caller+0x1ad/0x240 [] ? nfs_fs_mount+0xc37/0xd80 [nfs] [] nfs_fs_mount+0x2c5/0xd80 [nfs] [] ? nfs_clone_super+0x140/0x140 [nfs] [] ? nfs_clone_sb_security+0x40/0x40 [nfs] [] mount_fs+0x43/0x1b0 [] ? __alloc_percpu+0x10/0x20 [] vfs_kern_mount+0x76/0x120 [] do_mount+0x237/0xa80 Signed-off-by: Peng Tao Signed-off-by: Trond Myklebust --- fs/nfs/nfs3client.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c index 52e2344bf9a1..9e9fa347a948 100644 --- a/fs/nfs/nfs3client.c +++ b/fs/nfs/nfs3client.c @@ -1,5 +1,6 @@ #include #include +#include #include "internal.h" #include "nfs3_fs.h" @@ -89,6 +90,12 @@ struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp, }; struct rpc_timeout ds_timeout; struct nfs_client *clp; + char buf[INET6_ADDRSTRLEN + 1]; + + /* fake a hostname because lockd wants it */ + if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0) + return ERR_PTR(-EINVAL); + cl_init.hostname = buf; /* Use the MDS nfs_client cl_ipaddr. */ nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);