This is a note to let you know that I've just added the patch titled
mhi: Fix double dma free
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mhi-fix-double-dma-free.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4d8af0ac6f9cb6fd7433ad682834390149fb7b96
Author: Loic Poulain <loic.poulain@xxxxxxxxxx>
Date: Wed Feb 10 13:55:38 2021 +0530
mhi: Fix double dma free
[ Upstream commit db4e8de1935b0202960e9ebb88ab93e8bd1e66b1 ]
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.
Link: https://lore.kernel.org/r/1612894264-15956-1-git-send-email-loic.poulain@xxxxxxxxxx
Fixes: a7f422f2f89e ("bus: mhi: Fix channel close issue on driver remove")
Reported-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Tested-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210210082538.2494-2-manivannan.sadhasivam@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index f0697f433c2f1..08c45457c90fe 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -552,6 +552,9 @@ 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);
