Why Kernel panic when the EDAC modules are being loaded ?

Issue

• We see a kernel panic when the EDAC modules are being loaded.

• Can see following logs in dmesg output

EDAC PCI: Removed device 0 for e752x_edac EDAC PCI controller: DEV 0000:00:00.0
EDAC MC: Removed device 0 for e752x_edac E7520: DEV 0000:00:00.0
EDAC MC: Ver: 2.1.0 Jan 29 2013
EDAC e752x: tolm = 80000, remapbase = ffc000, remaplimit = 0
EDAC MC0: Giving out device to 'e752x_edac' 'E7520': DEV 0000:00:00.0
EDAC PCI0: Giving out device to module 'e752x_edac' controller 'EDAC PCI controller': DEV '0000:00:00.0' (POLLED)
EDAC PCI: Removed device 0 for e752x_edac EDAC PCI controller: DEV 0000:00:00.0
EDAC MC: Removed device 0 for e752x_edac E7520: DEV 0000:00:00.0
EDAC MC: Ver: 2.1.0 Jan 29 2013
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: [<ffffffff8129ab70>] pci_get_slot+0x50/0x90
PGD 7a928067 PUD 7da23067 PMD 0
Oops: 0000 [#1] SMP

And following panic traces

  [exception RIP: pci_get_slot+80]
    RIP: ffffffff8129ab70  RSP: ffff88007ada3be8  RFLAGS: 00010217
    RAX: 0000000000000000  RBX: ffff880037ce8000  RCX: ffffffff8129a710
    RDX: ffff88007e683c28  RSI: 0000000000000000  RDI: ffffffff81af2520
    RBP: ffff88007ada3bf8   R8: 0000000000000000   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: 0000000000000000
    R13: ffff88007b7b8940  R14: 0000000000000000  R15: ffff88007e67e090
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #9 [ffff88007ada3c00] pci_scan_single_device at ffffffff814f604c
#10 [ffff88007ada3c50] e752x_init_one at ffffffffa02bc233 [e752x_edac]
#11 [ffff88007ada3d40] local_pci_probe at ffffffff81298fc7
#12 [ffff88007ada3d50] pci_device_probe at ffffffff8129a1b1
#13 [ffff88007ada3db0] driver_probe_device at ffffffff8135ecc0
#14 [ffff88007ada3de0] __driver_attach at ffffffff8135ef6b
#15 [ffff88007ada3e10] bus_for_each_dev at ffffffff8135e274
#16 [ffff88007ada3e50] driver_attach at ffffffff8135ea5e
#17 [ffff88007ada3e60] bus_add_driver at ffffffff8135daa8
#18 [ffff88007ada3ea0] driver_register at ffffffff8135f2b6
#19 [ffff88007ada3ee0] __pci_register_driver at ffffffff8129a416
#20 [ffff88007ada3f10] init_module at ffffffffa02bf031 [e752x_edac]
#21 [ffff88007ada3f20] do_one_initcall at ffffffff8100204c
#22 [ffff88007ada3f50] sys_init_module at ffffffff810b7551
#23 [ffff88007ada3f80] system_call_fastpath at ffffffff8100b072