linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Bhaumik Bhatt <bbhatt@codeaurora.org>
To: manivannan.sadhasivam@linaro.org
Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
	jhugo@codeaurora.org, linux-kernel@vger.kernel.org,
	loic.poulain@linaro.org, Bhaumik Bhatt <bbhatt@codeaurora.org>
Subject: [PATCH] bus: mhi: core: Validate channel ID when processing command completions
Date: Mon, 26 Apr 2021 16:58:58 -0700	[thread overview]
Message-ID: <1619481538-4435-1-git-send-email-bbhatt@codeaurora.org> (raw)

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


             reply	other threads:[~2021-04-26 23:59 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-26 23:58 Bhaumik Bhatt [this message]
2021-04-27  0:44 ` [PATCH] bus: mhi: core: Validate channel ID when processing command completions 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1619481538-4435-1-git-send-email-bbhatt@codeaurora.org \
    --to=bbhatt@codeaurora.org \
    --cc=hemantk@codeaurora.org \
    --cc=jhugo@codeaurora.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=loic.poulain@linaro.org \
    --cc=manivannan.sadhasivam@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).