diff mbox series

[v2] mhi: Fix double dma free

Message ID 1612894264-15956-1-git-send-email-loic.poulain@linaro.org
State Accepted
Commit db4e8de1935b0202960e9ebb88ab93e8bd1e66b1
Headers show
Series [v2] mhi: Fix double dma free | expand

Commit Message

Loic Poulain Feb. 9, 2021, 6:11 p.m. UTC
mhi_deinit_chan_ctxt functionthat takes care of unitializing channel
resources, including unmapping coherent MHI areas, can be called
from different path in case of controller unregistering/removal:
 - From a client driver remove callback, via mhi_unprepare_channel
 - From mhi_driver_remove that unitialize all channels

mhi_driver_remove()
|-> driver->remove()
|    |-> mhi_unprepare_channel()
|        |-> mhi_deinit_chan_ctxt()
|...
|-> mhi_deinit_chan_ctxt()

This leads to double dma freeing...

Fix that by preventing deinit for already uninitialized channel.

Fixes: a7f422f2f89e ("bus: mhi: Fix channel close issue on driver remove")
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

Reported-by: Kalle Valo <kvalo@codeaurora.org>
Tested-by: Kalle Valo <kvalo@codeaurora.org>

---
 v2: add Fixes tag

 drivers/bus/mhi/core/init.c | 3 +++
 1 file changed, 3 insertions(+)

-- 
2.7.4

Comments

Manivannan Sadhasivam Feb. 10, 2021, 8:14 a.m. UTC | #1
On Tue, Feb 09, 2021 at 07:11:04PM +0100, Loic Poulain wrote:
> mhi_deinit_chan_ctxt functionthat takes care of unitializing channel

> resources, including unmapping coherent MHI areas, can be called

> from different path in case of controller unregistering/removal:

>  - From a client driver remove callback, via mhi_unprepare_channel

>  - From mhi_driver_remove that unitialize all channels

> 

> mhi_driver_remove()

> |-> driver->remove()

> |    |-> mhi_unprepare_channel()

> |        |-> mhi_deinit_chan_ctxt()

> |...

> |-> mhi_deinit_chan_ctxt()

> 

> This leads to double dma freeing...

> 

> Fix that by preventing deinit for already uninitialized channel.

> 

> Fixes: a7f422f2f89e ("bus: mhi: Fix channel close issue on driver remove")

> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

> Reported-by: Kalle Valo <kvalo@codeaurora.org>

> Tested-by: Kalle Valo <kvalo@codeaurora.org>


Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>


Thanks,
Mani

> ---

>  v2: add Fixes tag

> 

>  drivers/bus/mhi/core/init.c | 3 +++

>  1 file changed, 3 insertions(+)

> 

> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c

> index aa575d3..be4eebb 100644

> --- a/drivers/bus/mhi/core/init.c

> +++ b/drivers/bus/mhi/core/init.c

> @@ -557,6 +557,9 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,

>  	tre_ring = &mhi_chan->tre_ring;

>  	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];

>  

> +	if (!chan_ctxt->rbase) /* Already uninitialized */

> +		return;

> +

>  	mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,

>  			  tre_ring->pre_aligned, tre_ring->dma_handle);

>  	vfree(buf_ring->base);

> -- 

> 2.7.4

>
patchwork-bot+linux-arm-msm@kernel.org March 1, 2021, 7:59 p.m. UTC | #2
Hello:

This patch was applied to qcom/linux.git (refs/heads/for-next):

On Tue,  9 Feb 2021 19:11:04 +0100 you wrote:
> mhi_deinit_chan_ctxt functionthat takes care of unitializing channel

> resources, including unmapping coherent MHI areas, can be called

> from different path in case of controller unregistering/removal:

>  - From a client driver remove callback, via mhi_unprepare_channel

>  - From mhi_driver_remove that unitialize all channels

> 

> mhi_driver_remove()

> |-> driver->remove()

> |    |-> mhi_unprepare_channel()

> |        |-> mhi_deinit_chan_ctxt()

> |...

> |-> mhi_deinit_chan_ctxt()

> 

> [...]


Here is the summary with links:
  - [v2] mhi: Fix double dma free
    https://git.kernel.org/qcom/c/db4e8de1935b

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index aa575d3..be4eebb 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -557,6 +557,9 @@  void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	tre_ring = &mhi_chan->tre_ring;
 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
 
+	if (!chan_ctxt->rbase) /* Already uninitialized */
+		return;
+
 	mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
 			  tre_ring->pre_aligned, tre_ring->dma_handle);
 	vfree(buf_ring->base);