switch segfault

PPP generic driver version 2.4.2
init started:  BusyBox v1.4.2 (2007-07-19 10:00:04 CEST) multi-call binary

Please press Enter to activate this console. CPU 0 Unable to handle kernel paging req
uest at virtual address 0000002c, epc == 8015423c, ra == 801938c8
Oops[#1]:
Cpu 0
$ 0   : 00000000 fffffffd 00000000 803aed80
$ 4   : 80d07800 003f3f3f 80287141 803aed90
$ 8   : 80a6bfe0 00008400 00000000 80aee000
$12   : 0000003f 0000002a 2ac7ab80 00000000
$16   : 80d07800 00001103 00001042 80d07800
$20   : 00000000 00008914 7fe40d34 7fe40d74
$24   : 00000010 2ac2c9a0
$28   : 80a6a000 80a6bdf0 00000000 801938c8
Hi    : 00000000
Lo    : 00000000
epc   : 8015423c     Not tainted
ra    : 801938c8 Status: 18008403    KERNEL EXL IE
Cause : 00800008
BadVA : 0000002c
PrId  : 0001800b
Modules linked in: ppp_async ppp_generic slhc crc_ccitt
Process ifconfig (pid: 2579, threadinfo=80a6a000, task=8083c000)
Stack : 80ddca08 8097f278 00000000 00000000 80d07800 801922b0 00e7c603 8005e4f0
        00000003 80c11000 ffffff82 00000000 80a6be60 80d07800 801f56f4 801f5578
        00000002 000081a4 fffffff2 00008913 00001042 00000003 7fe40ec4 00000000
        30687465 00000000 00000000 00000000 00001042 00000003 7fe40ec4 00000000
        7fe40d34 00008914 7fe40d34 80c92a00 7fe40ec4 004e0858 00000003 004099e8
        ...
Call Trace:[<801922b0>][<8005e4f0>][<801f56f4>][<801f5578>][<8018535c>][<8008489c>][<
8008489c>][<80084bac>][<80183acc>][<80184b88>][<80084c2c>][<8000ac00>][<8000ac00>]

Code: 8c620000  10820008  24630004 <8c42002c> 30420002  10400004  00000000  90c20000
 00021027
: Segmentation fault