[25/67] mfd: Fix twl-core oops while calling twl_i2c_* for unbound driver

From: Greg KH
Date: Tue Jan 03 2012 - 17:35:28 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ilya Yanok <yanok@xxxxxxxxxxx>

commit 8653be1afd60d6e8c36139b487e375b70357d9ef upstream.

Check inuse variable before trying to access twl_map to prevent
dereferencing of uninitialized variable.

Signed-off-by: Ilya Yanok <yanok@xxxxxxxxxxx>
Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/mfd/twl-core.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -362,13 +362,13 @@ int twl_i2c_write(u8 mod_no, u8 *value,
pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
return -EPERM;
}
- sid = twl_map[mod_no].sid;
- twl = &twl_modules[sid];
-
if (unlikely(!inuse)) {
- pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
+ pr_err("%s: not initialized\n", DRIVER_NAME);
return -EPERM;
}
+ sid = twl_map[mod_no].sid;
+ twl = &twl_modules[sid];
+
mutex_lock(&twl->xfer_lock);
/*
* [MSG1]: fill the register address data
@@ -419,13 +419,13 @@ int twl_i2c_read(u8 mod_no, u8 *value, u
pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
return -EPERM;
}
- sid = twl_map[mod_no].sid;
- twl = &twl_modules[sid];
-
if (unlikely(!inuse)) {
- pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
+ pr_err("%s: not initialized\n", DRIVER_NAME);
return -EPERM;
}
+ sid = twl_map[mod_no].sid;
+ twl = &twl_modules[sid];
+
mutex_lock(&twl->xfer_lock);
/* [MSG1] fill the register address data */
msg = &twl->xfer_msg[0];


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