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* [PATCH] bus: mhi: core: Validate channel ID when processing command completions
@ 2021-04-26 23:58 Bhaumik Bhatt
  2021-04-27  0:44 ` Hemant Kumar
                   ` (3 more replies)
  0 siblings, 4 replies; 8+ messages in thread
From: Bhaumik Bhatt @ 2021-04-26 23:58 UTC (permalink / raw)
  To: manivannan.sadhasivam
  Cc: linux-arm-msm, hemantk, jhugo, linux-kernel, loic.poulain, Bhaumik Bhatt

MHI reads the channel ID from the event ring element sent by the
device which can be any value between 0 and 255. In order to
prevent any out of bound accesses, add a check against the maximum
number of channels supported by the controller and those channels
not configured yet so as to skip processing of that event ring
element.

Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device")
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
---
 drivers/bus/mhi/core/main.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 22acde1..ed07421 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -773,11 +773,16 @@ static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
 	cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
 
 	chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
-	mhi_chan = &mhi_cntrl->mhi_chan[chan];
-	write_lock_bh(&mhi_chan->lock);
-	mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
-	complete(&mhi_chan->completion);
-	write_unlock_bh(&mhi_chan->lock);
+	WARN_ON(chan >= mhi_cntrl->max_chan);
+
+	if (chan < mhi_cntrl->max_chan &&
+	    mhi_cntrl->mhi_chan[chan].configured) {
+		mhi_chan = &mhi_cntrl->mhi_chan[chan];
+		write_lock_bh(&mhi_chan->lock);
+		mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
+		complete(&mhi_chan->completion);
+		write_unlock_bh(&mhi_chan->lock);
+	}
 
 	mhi_del_ring_element(mhi_cntrl, mhi_ring);
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH] bus: mhi: core: Validate channel ID when processing command completions
@ 2021-06-24 18:09 Bhaumik Bhatt
  2021-06-25  5:23 ` Manivannan Sadhasivam
  0 siblings, 1 reply; 8+ messages in thread
From: Bhaumik Bhatt @ 2021-06-24 18:09 UTC (permalink / raw)
  To: manivannan.sadhasivam; +Cc: linux-arm-msm, hemantk, linux-kernel, Bhaumik Bhatt

MHI reads the channel ID from the event ring element sent by the
device which can be any value between 0 and 255. In order to
prevent any out of bound accesses, add a check against the maximum
number of channels supported by the controller and those channels
not configured yet so as to skip processing of that event ring
element.

Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device")
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://lore.kernel.org/r/1619481538-4435-1-git-send-email-bbhatt@codeaurora.org
---
 drivers/bus/mhi/core/main.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 22acde1..fc9196f 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -773,11 +773,18 @@ static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
 	cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
 
 	chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
-	mhi_chan = &mhi_cntrl->mhi_chan[chan];
-	write_lock_bh(&mhi_chan->lock);
-	mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
-	complete(&mhi_chan->completion);
-	write_unlock_bh(&mhi_chan->lock);
+
+	if (chan < mhi_cntrl->max_chan &&
+	    mhi_cntrl->mhi_chan[chan].configured) {
+		mhi_chan = &mhi_cntrl->mhi_chan[chan];
+		write_lock_bh(&mhi_chan->lock);
+		mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
+		complete(&mhi_chan->completion);
+		write_unlock_bh(&mhi_chan->lock);
+	} else {
+		dev_err(&mhi_cntrl->mhi_dev->dev,
+			"Completion packet for invalid channel ID: %d\n", chan);
+	}
 
 	mhi_del_ring_element(mhi_cntrl, mhi_ring);
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-06-25  5:23 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-26 23:58 [PATCH] bus: mhi: core: Validate channel ID when processing command completions Bhaumik Bhatt
2021-04-27  0:44 ` Hemant Kumar
2021-05-04 17:19 ` Jeffrey Hugo
2021-05-21 13:17 ` Manivannan Sadhasivam
2021-05-24  4:42 ` Manivannan Sadhasivam
2021-05-24  4:58   ` Manivannan Sadhasivam
2021-06-24 18:09 Bhaumik Bhatt
2021-06-25  5:23 ` Manivannan Sadhasivam

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