Re: [PATCH] irqdomain/treewide: Keep firmware node unconditionally allocated

[Marc Zyngier <maz@kernel.org>]

Hi Thomas,

Catching up on email...

On 2020-07-09 10:53, Thomas Gleixner wrote:
> Quite some non OF/ACPI users of irqdomains allocate firmware nodes of 
> type
> IRQCHIP_FWNODE_NAMED or IRQCHIP_FWNODE_NAMED_ID and free them right 
> after
> creating the irqdomain. The only purpose of these FW nodes is to convey
> name information. When this was introduced the core code did not store 
> the
> pointer to the node in the irqdomain. A recent change stored the 
> firmware
> node pointer in irqdomain for other reasons and missed to notice that 
> the
> usage sites which do the alloc_fwnode/create_domain/free_fwnode 
> sequence
> are broken by this. Storing a dangling pointer is dangerous itself, but 
> in
> case that the domain is destroyed later on this leads to a double free.
> 
> Remove the freeing of the firmware node after creating the irqdomain 
> from
> all affected call sites to cure this.
> 
> Fixes: 711419e504eb ("irqdomain: Add the missing assignment of
> domain->fwnode for named fwnode")
> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: stable@vger.kernel.org

Urgh, that's pretty disastrous. My bad. Thanks a lot for having
put this patch together.

Acked-by: Marc Zyngier <maz@kernel.org>

If you can take it directly into Linus' tree, that'd be greatly
appreciated.

Thanks again,

         M.
-- 
Jazz is not dead. It just smells funny...