Re: find command misbehaves on debian with kernel 4.9

[Anthony DeRobertis <anthony@derobert.net>]

On Fri, Jun 30, 2017 at 10:15:15PM +0430, Cyrus Sh wrote:
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> Searching for system-resolved service following the recent
> vulnerability disclosure, I came to see a very strange behavior from
> find command.
> 
>  root@localhost:/# find . -name "*systemd-resolved*"
> ./usr/share/man/man8/systemd-resolved.service.8.gz
> ./usr/share/man/man8/systemd-resolved.8.gz
> 
> The command returns 0 or two lines as output for the first run. But if
> I run the command the second time I get:

I tried this on a VM running Jessie w/ the bpo kernel. It reproduces
here.

   vm:~# echo 1 > /proc/sys/vm/drop_caches 
   vm:~# cd /
   vm:/# find . -name "*systemd-resolved*"
   ./usr/share/man/man8/systemd-resolved.service.8.gz
   ./usr/share/man/man8/systemd-resolved.8.gz
   vm:/# find . -name "*systemd-resolved*"
   ./usr/share/man/man8/systemd-resolved.service.8.gz
   ./usr/share/man/man8/systemd-resolved.8.gz
   ./lib/systemd/system/systemd-resolved.service
   ./lib/systemd/systemd-resolved
   
Although it only happened once. I tried another 20-odd times, even using 3 for
drop_caches, and couldn't make it happen again.

But on another VM, on the first try. So apparently drop_caches isn't
strong enough to make it happen again