NFS: Fix a NULL pointer dereference of migration recovery ops for v4.2 client
---Steps to Reproduce-- <nfs-server> # cat /etc/exports /nfs/referal *(rw,insecure,no_subtree_check,no_root_squash,crossmnt) /nfs/old *(ro,insecure,subtree_check,root_squash,crossmnt) <nfs-client> # mount -t nfs nfs-server:/nfs/ /mnt/ # ll /mnt/*/ <nfs-server> # cat /etc/exports /nfs/referal *(rw,insecure,no_subtree_check,no_root_squash,crossmnt,refer=/nfs/old/@nfs-server) /nfs/old *(ro,insecure,subtree_check,root_squash,crossmnt) # service nfs restart <nfs-client> # ll /mnt/*/ --->>>>> oops here [ 5123.102925] BUG: unable to handle kernel NULL pointer dereference at (null) [ 5123.103363] IP: [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4] [ 5123.103752] PGD 587b9067 PUD 3cbf5067 PMD 0 [ 5123.104131] Oops: 0000 [#1] [ 5123.104529] Modules linked in: nfsv4(OE) nfs(OE) fscache(E) nfsd(OE) xfs libcrc32c iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi coretemp crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev vmw_balloon parport_pc parport i2c_piix4 shpchp auth_rpcgss nfs_acl vmw_vmci lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi serio_raw scsi_transport_spi e1000 mptscsih mptbase ata_generic pata_acpi [last unloaded: nfsd] [ 5123.105887] CPU: 0 PID: 15853 Comm: ::1-manager Tainted: G OE 4.2.0-rc6+ #214 [ 5123.106358] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014 [ 5123.106860] task: ffff88007620f300 ti: ffff88005877c000 task.ti: ffff88005877c000 [ 5123.107363] RIP: 0010:[<ffffffffa03ed38b>] [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4] [ 5123.107909] RSP: 0018:ffff88005877fdb8 EFLAGS: 00010246 [ 5123.108435] RAX: ffff880053f3bc00 RBX: ffff88006ce6c908 RCX: ffff880053a0d240 [ 5123.108968] RDX: ffffea0000e6d940 RSI: ffff8800399a0000 RDI: ffff88006ce6c908 [ 5123.109503] RBP: ffff88005877fe28 R08: ffffffff81c708a0 R09: 0000000000000000 [ 5123.110045] R10: 00000000000001a2 R11: ffff88003ba7f5c8 R12: ffff880054c55800 [ 5123.110618] R13: 0000000000000000 R14: ffff880053a0d240 R15: ffff880053a0d240 [ 5123.111169] FS: 0000000000000000(0000) GS:ffffffff81c27000(0000) knlGS:0000000000000000 [ 5123.111726] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5123.112286] CR2: 0000000000000000 CR3: 0000000054cac000 CR4: 00000000001406f0 [ 5123.112888] Stack: [ 5123.113458] ffffea0000e6d940 ffff8800399a0000 00000000000167d0 0000000000000000 [ 5123.114049] 0000000000000000 0000000000000000 0000000000000000 00000000a7ec82c6 [ 5123.114662] ffff88005877fe18 ffffea0000e6d940 ffff8800399a0000 ffff880054c55800 [ 5123.115264] Call Trace: [ 5123.115868] [<ffffffffa03fb44b>] nfs4_try_migration+0xbb/0x220 [nfsv4] [ 5123.116487] [<ffffffffa03fcb3b>] nfs4_run_state_manager+0x4ab/0x7b0 [nfsv4] [ 5123.117104] [<ffffffffa03fc690>] ? nfs4_do_reclaim+0x510/0x510 [nfsv4] [ 5123.117813] [<ffffffff810a4527>] kthread+0xd7/0xf0 [ 5123.118456] [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160 [ 5123.119108] [<ffffffff816d9cdf>] ret_from_fork+0x3f/0x70 [ 5123.119723] [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160 [ 5123.120329] Code: 4c 8b 6a 58 74 17 eb 52 48 8d 55 a8 89 c6 4c 89 e7 e8 4a b5 ff ff 8b 45 b0 85 c0 74 1c 4c 89 f9 48 8b 55 90 48 8b 75 98 48 89 df <41> ff 55 00 3d e8 d8 ff ff 41 89 c6 74 cf 48 8b 4d c8 65 48 33 [ 5123.121643] RIP [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4] [ 5123.122308] RSP <ffff88005877fdb8> [ 5123.122942] CR2: 0000000000000000 Fixes: ec011fe8 ("NFS: Introduce a vector of migration recovery ops") Cc: stable@vger.kernel.org # v3.13+ Signed-off-by:Kinglong Mee <kinglongmee@gmail.com> Signed-off-by:
Trond Myklebust <trond.myklebust@primarydata.com>
Showing