| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAHUa44F3a+iWYy2+uKasc7ob-6rbUojQe1GJmmVCtfWrPMTT7Q@mail.gmail.com>
Date: Mon, 2 Jun 2025 15:09:35 +0200
From: Jens Wiklander <jens.wiklander@...aro.org>
To: linux-kernel@...r.kernel.org, op-tee@...ts.trustedfirmware.org
Cc: Jerome Forissier <jerome.forissier@...aro.org>, Sudeep Holla <sudeep.holla@....com>,
Sumit Garg <sumit.garg@...nel.org>
Subject: Re: [PATCH] optee: ffa: fix sleep in atomic context
[CC Sumit Garg <sumit.garg@...nel.org>]
Cheers,
Jens
On Mon, Jun 2, 2025 at 2:05 PM Jens Wiklander <jens.wiklander@...aro.org> wrote:
>
> The OP-TEE driver registers the function notif_callback() for FF-A
> notifications. However, this function is called in an atomic context
> leading to errors like this when processing asynchronous notifications:
>
> | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258
> | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0
> | preempt_count: 1, expected: 0
> | RCU nest depth: 0, expected: 0
> | CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0-00019-g657536ebe0aa #13
> | Hardware name: linux,dummy-virt (DT)
> | Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn
> | Call trace:
> | show_stack+0x18/0x24 (C)
> | dump_stack_lvl+0x78/0x90
> | dump_stack+0x18/0x24
> | __might_resched+0x114/0x170
> | __might_sleep+0x48/0x98
> | mutex_lock+0x24/0x80
> | optee_get_msg_arg+0x7c/0x21c
> | simple_call_with_arg+0x50/0xc0
> | optee_do_bottom_half+0x14/0x20
> | notif_callback+0x3c/0x48
> | handle_notif_callbacks+0x9c/0xe0
> | notif_get_and_handle+0x40/0x88
> | generic_exec_single+0x80/0xc0
> | smp_call_function_single+0xfc/0x1a0
> | notif_pcpu_irq_work_fn+0x2c/0x38
> | process_one_work+0x14c/0x2b4
> | worker_thread+0x2e4/0x3e0
> | kthread+0x13c/0x210
> | ret_from_fork+0x10/0x20
>
> Fix this by adding work queue to process the notification in a
> non-atomic context.
>
> Fixes: d0476a59de06 ("optee: ffa_abi: add asynchronous notifications")
> Signed-off-by: Jens Wiklander <jens.wiklander@...aro.org>
> ---
> drivers/tee/optee/ffa_abi.c | 41 ++++++++++++++++++++++++-------
> drivers/tee/optee/optee_private.h | 2 ++
> 2 files changed, 34 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index f3af5666bb11..f9ef7d94cebd 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -728,12 +728,21 @@ static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
> return true;
> }
>
> +static void notif_work_fn(struct work_struct *work)
> +{
> + struct optee_ffa *optee_ffa = container_of(work, struct optee_ffa,
> + notif_work);
> + struct optee *optee = container_of(optee_ffa, struct optee, ffa);
> +
> + optee_do_bottom_half(optee->ctx);
> +}
> +
> static void notif_callback(int notify_id, void *cb_data)
> {
> struct optee *optee = cb_data;
>
> if (notify_id == optee->ffa.bottom_half_value)
> - optee_do_bottom_half(optee->ctx);
> + queue_work(optee->ffa.notif_wq, &optee->ffa.notif_work);
> else
> optee_notif_send(optee, notify_id);
> }
> @@ -817,9 +826,11 @@ static void optee_ffa_remove(struct ffa_device *ffa_dev)
> struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
> u32 bottom_half_id = optee->ffa.bottom_half_value;
>
> - if (bottom_half_id != U32_MAX)
> + if (bottom_half_id != U32_MAX) {
> ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
> bottom_half_id);
> + destroy_workqueue(optee->ffa.notif_wq);
> + }
> optee_remove_common(optee);
>
> mutex_destroy(&optee->ffa.mutex);
> @@ -835,6 +846,13 @@ static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
> u32 notif_id = 0;
> int rc;
>
> + INIT_WORK(&optee->ffa.notif_work, notif_work_fn);
> + optee->ffa.notif_wq = create_workqueue("optee_notification");
> + if (!optee->ffa.notif_wq) {
> + rc = -EINVAL;
> + goto err;
> + }
> +
> while (true) {
> rc = ffa_dev->ops->notifier_ops->notify_request(ffa_dev,
> is_per_vcpu,
> @@ -851,19 +869,24 @@ static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
> * notifications in that case.
> */
> if (rc != -EACCES)
> - return rc;
> + goto err_wq;
> notif_id++;
> if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE)
> - return rc;
> + goto err_wq;
> }
> optee->ffa.bottom_half_value = notif_id;
>
> rc = enable_async_notif(optee);
> - if (rc < 0) {
> - ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
> - notif_id);
> - optee->ffa.bottom_half_value = U32_MAX;
> - }
> + if (rc < 0)
> + goto err_rel;
> +
> + return 0;
> +err_rel:
> + ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev, notif_id);
> +err_wq:
> + destroy_workqueue(optee->ffa.notif_wq);
> +err:
> + optee->ffa.bottom_half_value = U32_MAX;
>
> return rc;
> }
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index dc0f355ef72a..9526087f0e68 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -165,6 +165,8 @@ struct optee_ffa {
> /* Serializes access to @global_ids */
> struct mutex mutex;
> struct rhashtable global_ids;
> + struct workqueue_struct *notif_wq;
> + struct work_struct notif_work;
> };
>
> struct optee;
> --
> 2.43.0
>
Powered by blists - more mailing lists