[RHEL5.5] Kernel Panic "NULL pointer dereference" in "kfree" called from "acpi_bus_receive_event"

Issue

• System had a kernel crash with the following core dump output:

Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: [<ffffffff8000b4e4>] kfree+0x5e/0x1d8
Pid: 10208, comm: hald-addon-acpi Tainted: PF     2.6.18-194.11.4.el5 #1
RIP: 0010:[<ffffffff8000b4e4>]  [<ffffffff8000b4e4>] kfree+0x5e/0x1d8
Process hald-addon-acpi (pid: 10208, threadinfo ffff81107dc78000, task ffff81107d014040)
Call Trace:
 [<ffffffff80196479>] acpi_bus_receive_event+0xfe/0x121
 [<ffffffff8008cf9d>] default_wake_function+0x0/0xe
 [<ffffffff801a0431>] acpi_system_read_event+0x53/0xe6
 [<ffffffff8000b729>] vfs_read+0xcb/0x171
 [<ffffffff80011c3b>] sys_read+0x45/0x6e
 [<ffffffff8005d28d>] tracesys+0xd5/0xe0

Code: 48 8b 00 48 83 e0 fc 48 8d 14 30 48 8b 02 25 00 40 02 00 48 
RIP  [<ffffffff8000b4e4>] kfree+0x5e/0x1d8