[ILUG] Grep is segfaulting...

[John Allman]

I'm worried this may be indicative of a more serious problem. The system 
is running debian stable and every time i run grep it segfaults.

I made a file called /tmp/break with the following contents:

bork
bork
bork

the following is the output of strace grep bork /tmp/break:

execve("/bin/grep", ["grep", "bork", "/tmp/break"], [/* 14 vars */]) = 0
uname({sys="Linux", node="mail", ...})  = 0
brk(0)                                  = 0x80548f4
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or 
directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=8366, ...}) = 0
old_mmap(NULL, 8366, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40014000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\30\222"..., 
1024) = 1024
fstat64(3, {st_mode=S_IFREG|0755, st_size=1153784, ...}) = 0
old_mmap(NULL, 1166560, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40017000
mprotect(0x4012a000, 40160, PROT_NONE)  = 0
old_mmap(0x4012a000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 
3, 0x113000) = 0x4012a000
old_mmap(0x40130000, 15584, PROT_READ|PROT_WRITE, 
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x40130000
close(3)                                = 0
munmap(0x40014000, 8366)                = 0
brk(0)                                  = 0x80548f4
brk(0x805491c)                          = 0x805491c
brk(0x8055000)                          = 0x8055000
--- SIGSEGV (Segmentation fault) ---
+++ killed by SIGSEGV +++

I really am at a loss as to what is happening. I would appreciate any 
suggestions to find out more information or any advice on the matter as 
when something as essential as grep breaks i get twitchy about a 
horrible crash in the near future.

Thanks

John