Re: [PATCH v2 RESEND] EDAC/ti: Fix possible null pointer dereference in _emif_get_id()

[Avadhut Naik]

On 7/24/24 02:10, Ma Ke wrote:
> In _emif_get_id(), of_get_address() may return NULL which is later
> dereferenced. Fix this bug by adding NULL check.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 86a18ee21e5e ("EDAC, ti: Add support for TI keystone and DRA7xx EDAC")
> Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
> ---
> Changes in v2:
> - added Cc stable line.
> ---
>  drivers/edac/ti_edac.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/edac/ti_edac.c b/drivers/edac/ti_edac.c
> index 29723c9592f7..db23887b2d81 100644
> --- a/drivers/edac/ti_edac.c
> +++ b/drivers/edac/ti_edac.c
> @@ -207,6 +207,9 @@ static int _emif_get_id(struct device_node *node)
>  	int my_id = 0;
>  
>  	addrp = of_get_address(node, 0, NULL, NULL);
> +	if (!addrp)
> +		return -EINVAL;
> +
>  	my_addr = (u32)of_translate_address(node, addrp);
>  
>  	for_each_matching_node(np, ti_edac_of_match) {

IIUC, the original v2 submitted seems to differ from this RESEND patch
https://lore.kernel.org/linux-edac/20240718134834.826890-1-make24@xxxxxxxxxxx/

Snippet from submitting-patches:
Don’t add “RESEND” when you are submitting a modified version of your patch or patch series - “RESEND” only applies to resubmission of a patch or patch series which have not been modified in any way from the previous submission.

Any specific reason for this change?

>From a brief look, it seems that the original v2 was correct.
Check for NULL pointer deference might be required in both places
in _emif_get_id().

Also, some more context on how this was noticed might help.
Was it through mere observation?

Thanks,
Avadhut Naik