Re: [BUG: kernel/irq/proc.c] unprotected iteration over the IRQ action list in name_unique()

[Dmitry Adamushko]

On 14/03/07, Dmitry Adamushko <dmitry.adamushko@xxxxxxxxx> wrote:

> 1-st issue:  unprotected iteration over the IRQ action list in name_unique()
>
>
> the racing sequences:
>
> [ 1 ]  request_irq() -> setup_irq() -> register_handler_proc() ->
> name_unique() -> iterate over the action list (*)
>
> setup_irq() releases a desc->lock before calling register_handler_proc().
>
> [ 2 ]  free_irq() -> delete some element while (*) is still in progress -> bum!

"delete" == remove from the list + kfree() as synchronize_irq() is not
going to prevent it for obvious reasons.

Of course, request_irq() and free_irq() are called for the same
/shared/ irq line but for /different/ handlers.

Looks too obvious to be true. I already expected someone prooving me
wrong, at the very least by pointing out a special option of vim to
activate some hidden synchronization code :o)


--
Best regards,
Dmitry Adamushko
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