RHEL5: Kernel crashes on boot due to "NULL pointer dereference at find_busiest_group+0x442" in find_busiest_group()

Issue

• Kernel crashes on boot due to "NULL pointer dereference at find_busiest_group+0x442" in find_busiest_group() when booting with 2 CPUs with 5 cores each.

Unable to handle kernel NULL pointer dereference at 0000000000000028 RIP: 
 [<ffffffff8008e27c>] find_busiest_group+0x442/0x5f9
PGD 0 
Oops: 0000 [1] SMP 
last sysfs file: 
CPU 0 
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.18-411.el5 #1
RIP: 0010:[<ffffffff8008e27c>]  [<ffffffff8008e27c>] find_busiest_group+0x442/0x5f9
RSP: 0000:ffff810b40059a70  EFLAGS: 00010002
RAX: 0000000000007680 RBX: ffff810b3fc50000 RCX: 0000000000000000
RDX: 0000000000000118 RSI: 0000000000000143 RDI: 00000000000000c0
RBP: ffff810b40059b60 R08: 000000000000000a R09: 0000000000000036
R10: ffff810b3fc50188 R11: 0000000000000080 R12: ffff810b3fc50000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000230
FS:  0000000000000000(0000) GS:ffffffff80436000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000028 CR3: 0000000000201000 CR4: 00000000000006a0
Process swapper (pid: 1, threadinfo ffff810b40058000, task ffff8101276cf7b0)
Stack:  0000000000000000 ffff810b40059bd0 ffff810b40059bfc 0000000200000000
 ffff810b40059bf0 0000000000000000 ffff810009005a40 ffff810b3fc50000
 0000000000000000 0000000000000000 0000000000011800 0000000000000000
Call Trace:
 [<ffffffff800626a1>] __sched_text_start+0x2d1/0xbd0
 [<ffffffff80063171>] wait_for_completion+0x79/0xa2
 [<ffffffff8008f4cd>] default_wake_function+0x0/0xe
 [<ffffffff800a04b7>] call_usermodehelper_keys+0xe3/0xf8
 [<ffffffff800a04cc>] __call_usermodehelper+0x0/0x61
 [<ffffffff80159843>] kobject_uevent_env+0x407/0x450
 [<ffffffff80158fde>] kobject_add+0xd2/0x191
 [<ffffffff801591b9>] kobject_register+0x33/0x39
 [<ffffffff801d06ba>] sysdev_register+0x5c/0xec
 [<ffffffff801d714b>] register_memory+0x28/0x4b
 [<ffffffff801d71d8>] add_memory_block+0x6a/0xb8
 [<ffffffff80491649>] memory_dev_init+0x67/0x95
 [<ffffffff80491550>] driver_init+0x2c/0x32
 [<ffffffff80471a01>] init+0x19c/0x2f7
 [<ffffffff8005dfc1>] child_rip+0xa/0x11
 [<ffffffff8018b489>] acpi_ds_init_one_object+0x0/0x80
 [<ffffffff80471865>] init+0x0/0x2f7
 [<ffffffff8005dfb7>] child_rip+0x0/0x11


Code: 48 0f af 51 28 48 8b 9d 30 ff ff ff 48 39 d0 48 0f 47 c2 48 
RIP  [<ffffffff8008e27c>] find_busiest_group+0x442/0x5f9
 RSP <ffff810b40059a70>
CR2: 0000000000000028
 <0>Kernel panic - not syncing: Fatal exception