Re: OOps in exec_usermodehelper

["Andrew Morton" <morton@nortelnetworks.com>]

Petr Vandrovec wrote:
> 
> Hi,
>   I have one small problem with 2.4.0-test11 and exec_usermodehelper.
> When vmware modules shutdown (specifically vmnet-netifup), kernel tries
> to load some module through call_usermodehelper, but unfortunately
> from task which has current->files == NULL.
> 
>   So it prints message:
> 
> waitpid(19457) failed, -512
> 
>   and then it oopses in
> 
> for (i = 0; i < current->files->max_fds; i++) {
>   if (current->files->fd[i]) close(i);
> }
> 
> (In log, there is first waitpid, and then oopses from current->files == NULL,
> which I do not quite understand).
> 
> Should I look into this more deeply, or is correct fix just add
> 
> if (current->files) {
>   for (i = 0; ..... ) ...
> }
> 
> into exec_usermodehelper?

No.  Then it just blows up somewhere else.

The root cause here is that we're starting a kernel thread
from within a half-exitted parent.  I'll be coding a fix 
later today.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/