[bug report] tee: add supp_nowait flag in tee_context struct

[bug report] tee: add supp_nowait flag in tee_context struct

[Dan Carpenter]

Hello Sumit Garg,

The patch 42bf4152d8a7: "tee: add supp_nowait flag in tee_context
struct" from Jan 29, 2019, leads to the following static checker
warning:

	drivers/tee/tee_core.c:996 tee_client_open_context()
	error: 'ctx' dereferencing possible ERR_PTR()

drivers/tee/tee_core.c
    986 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
                                        ^^^^^^^^^^^^^^^^^^^^^^^^
ctx can be ERR_PTR(-ENOMEM);

    987 
    988 	put_device(put_dev);
    989 	/*
    990 	 * Default behaviour for in kernel client is to not wait for
    991 	 * tee-supplicant if not present for any requests in this context.
    992 	 * Also this flag could be configured again before call to
    993 	 * tee_client_open_session() if any in kernel client requires
    994 	 * different behaviour.
    995 	 */
--> 996 	ctx->supp_nowait = true;
                ^^^^^^^^^^^^^^^^
And it leads to an Oops here.

    997 	return ctx;
    998 }

regards,
dan carpenter

Re: [bug report] tee: add supp_nowait flag in tee_context struct

[Sumit Garg]

Hi Dan Carpenter,

Thanks for this bug report. I have sent corresponding fix in upstream [1].

[1] https://lkml.org/lkml/2019/2/20/37

Regards,
Sumit

On Tue, 19 Feb 2019 at 18:56, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> Hello Sumit Garg,
>
> The patch 42bf4152d8a7: "tee: add supp_nowait flag in tee_context
> struct" from Jan 29, 2019, leads to the following static checker
> warning:
>
>         drivers/tee/tee_core.c:996 tee_client_open_context()
>         error: 'ctx' dereferencing possible ERR_PTR()
>
> drivers/tee/tee_core.c
>     986         } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
>                                         ^^^^^^^^^^^^^^^^^^^^^^^^
> ctx can be ERR_PTR(-ENOMEM);
>
>     987
>     988         put_device(put_dev);
>     989         /*
>     990          * Default behaviour for in kernel client is to not wait for
>     991          * tee-supplicant if not present for any requests in this context.
>     992          * Also this flag could be configured again before call to
>     993          * tee_client_open_session() if any in kernel client requires
>     994          * different behaviour.
>     995          */
> --> 996         ctx->supp_nowait = true;
>                 ^^^^^^^^^^^^^^^^
> And it leads to an Oops here.
>
>     997         return ctx;
>     998 }
>
> regards,
> dan carpenter