Linux-1.2.11-elf NULL pointer dereference

Juha Virtanen (jiivee@hut.fi)
Thu, 6 Jul 1995 18:10:09 +0300 (EET DST)


Hello all,

I found this message on my screen today.

Jul 6 05:29:02 iguana kernel: general protection: 0000
Jul 6 05:29:02 iguana kernel: EIP: 0010:0014d51f
Jul 6 05:29:02 iguana kernel: EFLAGS: 00010246
Jul 6 05:29:02 iguana kernel: eax: 00caef24 ebx: 005468c0 ecx: 00000801 edx: 00198ef0
Jul 6 05:29:02 iguana kernel: esi: 00caef74 edi: 00000003 ebp: 00059005 esp: 00caef04
Jul 6 05:29:02 iguana kernel: ds: 0018 es: 0018 fs: 002b gs: 002b ss: 0018
Jul 6 05:29:02 iguana kernel: Process ftp_admin (pid: 17641, process nr: 39, stackpage=00cae000)
Jul 6 05:29:02 iguana kernel: Stack: 005468c0 00059005 00000003 00caef24 005468c0 00caef74 00caef74 00000003
Jul 6 05:29:02 iguana kernel: 005468c0 000502b5 0012bfd1 005468c0 00059005 00000003 00caef74 00000000
Jul 6 05:29:02 iguana kernel: 00caef74 00caefb4 bffffc18 00000000 0012c208 005468c0 00059005 00000003
Jul 6 05:29:02 iguana kernel: Call Trace: 0012bfd1 0012c208 0012c300 001294d9 00110359 0011002b 0011002b
Jul 6 05:29:02 iguana kernel: Code: e8 3c fc ff ff 89 c6 83 c4 10 85 f6 75 23 8b 44 24 14 39 43

value function function start addr
---------------------------------------------------
EIP:
0014d51f ext2_lookup 0014d440

call trace:
0012bfd1 lookup 0012bee0
0012c208 _namei 0012c1b0
0012c300 namei 0012c2d0
001294d9 sys_newstat 001294b0
00110359 system_call 00110300
0011002b do_signal 0010ff00
0011002b do_signal 0010ff00

Machine didn't crash or hang, actually it is still running.

System configuration: Linux-1.2.11 with HJ Lu's ELF patches and
my process accounting pathces, gcc-2.6.3-ELF, libc.so-5.0.9,
libc.so.4.7.2, ld.so.1.7.3, binutils-2.5.2l.17.

Machine is a i486/33 with 16MB ram, ISA-bus, AHA 1542c+1GB disk
and SMC Ultra NIC.

I can provide more detailed configuration information if
necessary.

Juha