[PATCH v1 2/2] i2c: dev: Force case user pointers in compat_i2cdev_ioctl()

From: Andy Shevchenko
Date: Mon Apr 11 2022 - 14:08:04 EST


Sparse has warned us about wrong address space for user pointers:

i2c-dev.c:561:50: warning: incorrect type in initializer (different address spaces)
i2c-dev.c:561:50: expected unsigned char [usertype] *buf
i2c-dev.c:561:50: got void [noderef] __user *

Force cast the pointer to (__u8 *) that is used by I²C core code.

Note, this is an additional fix to the previously addressed similar issue
in the I2C_RDWR case in the same function.

Fixes: 3265a7e6b41b ("i2c: dev: Add __user annotation")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/i2c/i2c-dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 6fd2b6718b08..ab0adaa130da 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -557,7 +557,7 @@ static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned lo
.addr = umsg.addr,
.flags = umsg.flags,
.len = umsg.len,
- .buf = compat_ptr(umsg.buf)
+ .buf = (__force __u8 *)compat_ptr(umsg.buf),
};
}

--
2.35.1