Lino,

On 01/04/2011 01:28 PM, Lino Sanfilippo wrote:
>> I tested fanotify in 2.6.37-rc7 and faced the following issue: when a
>> fanotify server process (started with open_perm set) segfaults the
>> kernel tries to open core dump file and here it is forced to wait a
>> permission result because fanotify server receives notifications on
>> file operations initiated by itself. Since fanotify server has crashed
>> the permission will never be granted. So the whole system hangs.
>
> Hmm I could not reproduce this with the latest state (ef9bf3b7144bee6ce) of
> branch 'origin/for-next' from git.infradead.org/users/eparis/notify.git
>
> What i did was:
> - register with fanotify
> - set mark for OPEN_PERM event
> - read an event
> - cause a segfault before response is returned to fanotify
>
> The process terminates and the core file is created as expected.
> Could you provide some code to trigger this?
>

The issue is still reproduced on ubuntu 11.04:

$ uname -a
Linux user-virtual-machine 2.6.38.2 #16 SMP Wed Jun 8 14:40:03 MSD 2011 
i686 i686 i386 GNU/Linux
$ g++ fanotify.c -o fanotify -lpthread
$ sudo su
$ ulimit -c unlimited
$ ./fanotify -o open_perm -C -m /

In other console:
$ ls

Then machine is dead.

-- 
Best regards,

Vasily Novikov | Software developer | Kaspersky Lab

Direct: +7 495 123 45 67 x2344 | Mobile: +7 964 786 44 82 | 
vasily.novikov@kaspersky.com
10/1, 1st Volokolamsky Proezd, Moscow, 123060, Russia | 
www.kaspersky.com,  www.securelist.com