From a7982a14b3012527a9583d12525cd0dc9f8d8934 Mon Sep 17 00:00:00 2001 From: Yang Xiwen Date: Mon, 16 Jun 2025 00:01:10 +0800 Subject: [PATCH] i2c: qup: jump out of the loop in case of timeout 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. Fixes: fbfab1ab0658 ("i2c: qup: reorganization of driver code to remove polling for qup v1") Signed-off-by: Yang Xiwen Cc: # v4.17+ Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20250616-qca-i2c-v1-1-2a8d37ee0a30@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 6059f585843eb..fc348924d5225 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); } -- 2.47.2