Re: aranym bug, manifests as "ida_remove called for id=13" on recent kernels

Geert Uytterhoeven
2010-10-10T20:18:04Z

On Sun, Oct 10, 2010 at 16:49, Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Sun, Oct 10, 2010 at 11:47:20AM +0200, Geert Uytterhoeven wrote:
>> > The cheapest way to reproduce is to boot with init=/bin/sh, then
>> > mount /proc and have stat("/proc/2/exe", &st) called; if stat()
>> > returns 0, we are fscked. ??The critical part is between return
>> > from proc_exe_link() (we'll leave it via if (!mm) return -ENOENT;)
>> > to return from __do_follow_link() -> do_follow_link() -> link_path_walk().
>>
>> I booted 2.6.36-rc7-atari-00360-g0dd2e6a (my current private test kernel) with
>> init=/bin/sh, mounted /proc, and tried
>>
>>     for i in $(seq 1000); do stat /proc/2/exe; done
>>
>> a few times, but I didn't see any ida_remove messages.
>> It cannot read the /proc/2/exe symlink, though.
>>
>> This is on aranym-0.9.9-1 from Ubuntu/amd64.
>
> stat -L /proc/2/exec, otherwise you'll hit lstat() instead of stat().
> And FWIW 0.9.10-1 squeeze/amd64 also triggers here...

Still, just "stat: cannot stat `proc/2/exe': No such file or directory" here...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds