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From: Yang Xiwen via B4 Relay <devnull+forbidden405.outlook.com@kernel.org>
To: Andi Shyti <andi.shyti@kernel.org>,
	 Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Cc: linux-arm-msm@vger.kernel.org, linux-i2c@vger.kernel.org,
	 linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	 Yang Xiwen <forbidden405@outlook.com>
Subject: [PATCH] i2c: qup: jump out of the loop in case of timeout
Date: Mon, 16 Jun 2025 00:01:10 +0800	[thread overview]
Message-ID: <20250616-qca-i2c-v1-1-2a8d37ee0a30@outlook.com> (raw)

From: Yang Xiwen <forbidden405@outlook.com>

Original logic only sets the return value but doesn't jump out of the
loop if the bus is kept active by a client. This is not expected. A
malicious or buggy i2c client can hang the kernel in this case and
should be avoided. This is observed during a long time test with a
PCA953x GPIO extender.

Fix it by changing the logic to not only sets the return value, but also
jumps out of the loop and return to the caller with -ETIMEDOUT.

Cc: stable@vger.kernel.org
Signed-off-by: Yang Xiwen <forbidden405@outlook.com>
---
 drivers/i2c/busses/i2c-qup.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 3a36d682ed57..5b053e51f4c9 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -452,8 +452,10 @@ static int qup_i2c_bus_active(struct qup_i2c_dev *qup, int len)
 		if (!(status & I2C_STATUS_BUS_ACTIVE))
 			break;
 
-		if (time_after(jiffies, timeout))
+		if (time_after(jiffies, timeout)) {
 			ret = -ETIMEDOUT;
+			break;
+		}
 
 		usleep_range(len, len * 2);
 	}

---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250615-qca-i2c-d41bb61aa59e

Best regards,
-- 
Yang Xiwen <forbidden405@outlook.com>



             reply	other threads:[~2025-06-15 16:01 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-15 16:01 Yang Xiwen via B4 Relay [this message]
2025-06-28 15:58 ` Yang Xiwen
2025-07-01 12:52   ` Konrad Dybcio
2025-07-16 22:17 ` Andi Shyti

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