RHEL 6 システムで `valid_swaphandles` が原因でカーネルがパニックになる

Issue

• 以下のメッセージが発生し、カーネルがパニックになります。

BUG: unable to handle kernel NULL pointer dereference at 0000000000000074
IP:[<ffffffff8114c14c>] valid_swaphandles+0x6c/0x150
PGD 0 
Oops:0000 [#1] SMP 
last sysfs file:/sys/devices/system/cpu/cpu79/cache/index2/shared_cpu_map
CPU 51 
Modules linked in: nls_utf8 bridge stp llc nfsd xfs exportfs nfs lockd fscache nfs_acl auth_rpcgss sunrpc ipmi_devintf ipmi_si ipmi_msghandler pcc_cpufreq bonding ipv6 power_meter be2net microcode vtms(U) netxen_nic sg serio_raw iTCO_wdt iTCO_vendor_support hpwdt hpilo i7core_edac edac_core shpchp ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif qla2xxx scsi_transport_fc scsi_tgt pata_acpi ata_generic ata_piix hpsa radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]

Pid:113542, comm: udevd Not tainted 2.6.32-220.13.1.el6.x86_64 #1 HP ProLiant DL980 G7
RIP:0010:[<ffffffff8114c14c>]  [<ffffffff8114c14c>] valid_swaphandles+0x6c/0x150
RSP:0000:ffff88101ab89c28  EFLAGS:00010246
RAX:000000000000d66d RBX:0040000017800000 RCX:0000000000000003
RDX:000000000000d66d RSI: ffff88101ab89c90 RDI: ffffffff81fab370
RBP: ffff88101ab89c68 R08: ffff881055234408 R09:0000000000000008
R10:00007ff78db18f80 R11:0000000000000000 R12:0040000017800000
R13:0040000017800000 R14:0000000000000000 R15: ffff88101ab89c90
FS:00007ff78e1b37a0(0000) GS:ffff882038960000(0000) knlGS:0000000000000000
CS:0010 DS:0000 ES:0000 CR0:0000000080050033
CR2:0000000000000074 CR3:0000001051835000 CR4:00000000000006e0
DR0:0000000000000000 DR1:0000000000000000 DR2:0000000000000000
DR3:0000000000000000 DR6:00000000ffff0ff0 DR7:0000000000000400
Process udevd (pid:113542, threadinfo ffff88101ab88000, task ffff881051f32ac0)
Stack:
 ffff88101ab89cc8 ffffffff00000003 ffff88101ab89cc8 ffff881055f4be08
<0> 00000000000200da ffff881055f4be08 00007ff7902181ad 00007ff7902181ad
<0> ffff88101ab89cc8 ffffffff8114b7bc ffff881000000008 5840000017800000
Call Trace:
 [<ffffffff8114b7bc>] swapin_readahead+0x2c/0xc0
 [<ffffffff8113bfdb>] handle_pte_fault+0x70b/0xb50
 [<ffffffff81124572>] ?__pagevec_free+0x42/0x90
 [<ffffffff8127940c>] ?__bitmap_weight+0x8c/0xb0
 [<ffffffff811394be>] ? unmap_vmas+0x6ee/0xbf0
 [<ffffffff8113c604>] handle_mm_fault+0x1e4/0x2b0
 [<ffffffff81042b79>] __do_page_fault+0x139/0x480
 [<ffffffff81094c72>] ? enqueue_hrtimer+0x82/0xd0
 [<ffffffff81095b03>] ?__hrtimer_start_range_ns+0x1a3/0x460
 [<ffffffff810d16ad>] ? audit_filter_rules+0x2d/0xa20
 [<ffffffff814f298e>] do_page_fault+0x3e/0xa0
 [<ffffffff814efd45>] page_fault+0x25/0x30
Code:3b 48 c7 c7 70 b3 fa 81 4d 89 e5 4c 8b 34 c5 80 b3 fa 81 89 4d c8 49 d3 ed 49 d3 e5 4d 85 ed 49 0f 45 dd e8 d7 36 3a 00 8b 4d c8 <41> 8b 56 74 b8 01 00 00 00 d3 e0 48 98 49 01 c5 49 39 d5 4c 0f 
RIP  [<ffffffff8114c14c>] valid_swaphandles+0x6c/0x150
 RSP <ffff88101ab89c28>
CR2:0000000000000074