ACK: [PATCH] acpi: fan: skip over fan info when the type field is NULL (LP: #1906540)

[ivanhu]

On 12/3/20 7:53 AM, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> It is possible for a read error on the thermal type field to end up
> with a null type field. (This can occur when a snap is not installed
> in --devmode and cannot access thermal control data).  This causes a
> segmentation fault when dereferencing the pointer. Add null checks to
> skip over such empty data fields.
> 
> Fixes: 10b9561f46f8 ("apci: fan: use newer thermal interface, test fans on loaded CPU (LP: #831905)")
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  src/acpi/fan/fan.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/src/acpi/fan/fan.c b/src/acpi/fan/fan.c
> index a42ad673..d31f51de 100644
> --- a/src/acpi/fan/fan.c
> +++ b/src/acpi/fan/fan.c
> @@ -215,9 +215,16 @@ static int fan_test2(fwts_framework *fw)
>  
>  	fwts_list_foreach(item1, fans1) {
>  		fan_info *info1 = fwts_list_data(fan_info *, item1);
> +
> +		if (!info1->type)
> +			continue;
> +
>  		fwts_list_foreach(item2, fans2) {
>  			fan_info *info2 = fwts_list_data(fan_info *, item2);
>  
> +			if (!info2->type)
> +				continue;
> +
>  			if (strcmp(info1->type, "Processor") == 0) {
>  				if (strcmp(info1->name, info2->name) == 0) {
>  					if (info2->cur_state < info1->cur_state) {
> 

Acked-by: Ivan Hu <ivan.hu at canonical.com>