From: Ilya Yanok <yanok@emcraft.com>
Date: Mon, 1 Aug 2011 21:00:28 +0000 (+0200)
Subject: mfd: Fix twl-core oops while calling twl_i2c_* for unbound driver
X-Git-Tag: firefly_0821_release~7541^2~2063
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=20e725bc08091c303a469d8e1e295bf3b360c778;p=firefly-linux-kernel-4.4.55.git

mfd: Fix twl-core oops while calling twl_i2c_* for unbound driver

commit 8653be1afd60d6e8c36139b487e375b70357d9ef upstream.

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

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index b8f2a4e7f6e7..f82413a98895 100644
--- 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, u8 reg, unsigned num_bytes)
 		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, u8 reg, unsigned num_bytes)
 		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];