1.3.20: NULL deref and /proc fall down go boom

Mike Shaver (shaver@neon.ingenia.com)
Sat, 19 Aug 1995 02:56:22 -0400 (EDT)

I've been running 1.3.20 for a couple of days now (I'd check how many
exactly, but /proc/uptime is gone =) ), and I think I found a problem.

>From /var/adm/syslog:
Aug 18 17:12:52 neon kernel: Unable to handle kernel NULL pointer dereference at virtual address c0000000
Aug 18 17:12:52 neon kernel: current->tss.cr3 = 00856000,
Aug 18 17:12:52 neon kernel: *pde = 00102067
Aug 18 17:12:52 neon kernel: *pte = 00000027

I'd wager it's something to do with /proc, because it's missing some
stuff. (On the other hand, what do I know?)
Total contents:
dr-xr-xr-x 5 root root 0 Aug 16 17:41 ./
drwxr-xr-x 20 root root 1024 Aug 16 16:25 ../
dr-xr-xr-x 3 root root 0 Aug 19 02:45 1/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 22/
dr-xr-xr-x 3 root root 0 Aug 19 02:47 3029/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 3470/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 40/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 42/
dr-xr-xr-x 3 sigh users 0 Aug 19 02:47 436/
dr-xr-xr-x 3 sigh users 0 Aug 19 02:47 438/
dr-xr-xr-x 3 bin root 0 Aug 19 02:45 44/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 46/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 50/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 52/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 55/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 57/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 59/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 6/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 61/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 66/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 7/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 73/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 75/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 80/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 8024/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 8031/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 81/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 8533/
dr-xr-xr-x 3 cpcallen users 0 Aug 19 02:45 8534/
dr-xr-xr-x 3 cpcallen users 0 Aug 19 02:45 8558/
dr-xr-xr-x 3 root root 0 Aug 19 02:45 8605/
dr-xr-xr-x 3 shaver users 0 Aug 19 02:45 8606/
dr-xr-xr-x 3 shaver users 0 Aug 19 02:47 8701/

My mount table shows /proc still there, and it won't let me unmount
it, because something's running in there (probably klogd or
something).

Remounting /proc doesn't help any.

GCC 2.7.0, DX4/100, 32 MB, VLB, Adaptec 2842 SCSI, Seagate SCSI-2
drive, SMC Ultra, moderately loaded (web pages, compiling, X, some
network connections). Pretty reliable kit (never had *any* hardware
problems, actually). Kernel compiled as ELF, (almost) all-ELF from
the Slackware beta. If you need to know anything else, let me know.

If someone can tell me how to make something (more?) useful out of the
NULL deref message above, I'll do my best.

Mike

-- 
#> Mike Shaver (shaver@ingenia.com)                                   <#
#> Technical specialist, pedant, packetsmith                          <#
#>                                 Ingenia Communications Corporation <#
#>               Research, Development, Support and Sleep Deprivation <#
#>                    Packets crafted, bugs found, rebellions quelled <#