bus: mhi: core: Remove double locking from mhi_driver_remove()
authorBhaumik Bhatt <bbhatt@codeaurora.org>
Thu, 15 Oct 2020 18:47:51 +0000 (11:47 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 30 Dec 2020 10:53:15 +0000 (11:53 +0100)
[ Upstream commit 9b627c25e70816a5e1dca940444b5029065b4d60 ]

There is double acquisition of the pm_lock from mhi_driver_remove()
function. Remove the read_lock_bh/read_unlock_bh calls for pm_lock
taken during a call to mhi_device_put() as the lock is acquired
within the function already. This will help avoid a potential
kernel panic.

Fixes: 189ff97cca53 ("bus: mhi: core: Add support for data transfer")
Reported-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/bus/mhi/core/init.c

index 0ffdebd..0a09f82 100644 (file)
@@ -1276,10 +1276,8 @@ static int mhi_driver_remove(struct device *dev)
                mutex_unlock(&mhi_chan->mutex);
        }
 
-       read_lock_bh(&mhi_cntrl->pm_lock);
        while (mhi_dev->dev_wake)
                mhi_device_put(mhi_dev);
-       read_unlock_bh(&mhi_cntrl->pm_lock);
 
        return 0;
 }