Re: [PATCH] firewire: core: fix invalid port index for parent device

> In a commit 24b7f8e5cd65 ("firewire: core: use helper functions for
> self
> ID sequence"), the enumeration over self ID sequence was refactored
> with
> some helper functions with KUnit tests. These helper functions are
> guaranteed to work expectedly by the KUnit tests, however their
> application
> includes a mistake to assign invalid value to the index of port
> connected
> to parent device.
> 
> This bug affects the case that any extra node devices which has three
> or
> more ports are connected to 1394 OHCI controller. In the case, the
> path
> to update the tree cache could hits WARN_ON(), and gets general
> protection
> fault due to the access to invalid address computed by the invalid
> value.
> 
> This commit fixes the bug to assign correct port index.
> 
> Cc: [email protected]
> Reported-by: Edmund Raile <[email protected]>
> Closes:
> https://lore.kernel.org/lkml/[email protected]/
> Fixes: 24b7f8e5cd65 ("firewire: core: use helper functions for self
> ID sequence")
> Signed-off-by: Takashi Sakamoto <[email protected]>
> ---
>  drivers/firewire/core-topology.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/firewire/core-topology.c
> b/drivers/firewire/core-topology.c
> index 6adadb11962e..892b94cfd626 100644
> --- a/drivers/firewire/core-topology.c
> +++ b/drivers/firewire/core-topology.c
> @@ -204,7 +204,7 @@ static struct fw_node *build_tree(struct fw_card
> *card, const u32 *sid, int self
>   // the node->ports array where the parent node should be.  Later,
>   // when we handle the parent node, we fix up the reference.
>   ++parent_count;
> - node->color = i;
> + node->color = port_index;
>   break;
> 
>   case PHY_PACKET_SELF_ID_PORT_STATUS_CHILD:
> --
> 2.45.2
Your patch is identical to my original proposals except for the line
numbers.


I've been using it since, no issues.

Thank you!

Tested-by: Edmund Raile <[email protected]>