If the __qcuefi pointer is not set, then in the original code, we would
hold onto the lock.  That means that if we tried to set it later, then
it would cause a deadlock.  Drop the lock on the error path.  That's
what all the callers are expecting.

Fixes: 759e7a2b62eb ("firmware: Add support for Qualcomm UEFI Secure Application")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/firmware/qcom/qcom_qseecom_uefisecapp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c b/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
index 6fefa4fe80e8..447246bd04be 100644
--- a/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
+++ b/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
@@ -715,6 +715,10 @@ static int qcuefi_set_reference(struct qcuefi_client *qcuefi)
 static struct qcuefi_client *qcuefi_acquire(void)
 {
 	mutex_lock(&__qcuefi_lock);
+	if (!__qcuefi) {
+		mutex_unlock(&__qcuefi_lock);
+		return NULL;
+	}
 	return __qcuefi;
 }
 
-- 
2.45.2

On Thu, 29 Aug 2024 22:23:04 +0300, Dan Carpenter wrote:
> If the __qcuefi pointer is not set, then in the original code, we would
> hold onto the lock.  That means that if we tried to set it later, then
> it would cause a deadlock.  Drop the lock on the error path.  That's
> what all the callers are expecting.
> 
> 

Applied, thanks!

[1/1] firmware: qcom: uefisecapp: Fix deadlock in qcuefi_acquire()
      commit: db213b0cfe3268d8b1d382b3bcc999c687a2567f

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>

On Thu, Aug 29, 2024 at 10:23:04PM GMT, Dan Carpenter wrote:
> If the __qcuefi pointer is not set, then in the original code, we would
> hold onto the lock.  That means that if we tried to set it later, then
> it would cause a deadlock.  Drop the lock on the error path.  That's
> what all the callers are expecting.
> 
> Fixes: 759e7a2b62eb ("firmware: Add support for Qualcomm UEFI Secure Application")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  drivers/firmware/qcom/qcom_qseecom_uefisecapp.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>


-- 
With best wishes
Dmitry