[media] au8522: Avoid memory leak for device config data

As reported by kmemleak:

	unreferenced object 0xffff880321e1da40 (size 32):
	  comm "modprobe", pid 3309, jiffies 4295019569 (age 2359.636s)
	  hex dump (first 32 bytes):
	    47 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  G...............
	    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
	  backtrace:
	    [<ffffffff82278c8e>] kmemleak_alloc+0x4e/0xb0
	    [<ffffffff8153c08c>] kmem_cache_alloc_trace+0x1ec/0x280
	    [<ffffffffa13a896a>] au8522_probe+0x19a/0xa30 [au8522_decoder]
	    [<ffffffff81de0032>] i2c_device_probe+0x2b2/0x490
	    [<ffffffff81ca7004>] driver_probe_device+0x454/0xd90
	    [<ffffffff81ca7c1b>] __device_attach_driver+0x17b/0x230
	    [<ffffffff81ca15da>] bus_for_each_drv+0x11a/0x1b0
	    [<ffffffff81ca6a4d>] __device_attach+0x1cd/0x2c0
	    [<ffffffff81ca7d43>] device_initial_probe+0x13/0x20
	    [<ffffffff81ca451f>] bus_probe_device+0x1af/0x250
	    [<ffffffff81c9e0f3>] device_add+0x943/0x13b0
	    [<ffffffff81c9eb7a>] device_register+0x1a/0x20
	    [<ffffffff81de8626>] i2c_new_device+0x5d6/0x8f0
	    [<ffffffffa0d88ea4>] v4l2_i2c_new_subdev_board+0x1e4/0x250 [v4l2_common]
	    [<ffffffffa0d88fe7>] v4l2_i2c_new_subdev+0xd7/0x110 [v4l2_common]
	    [<ffffffffa13b2f76>] au0828_card_analog_fe_setup+0x2e6/0x3f0 [au0828]

Checking where the error happens:
	(gdb) list *au8522_probe+0x19a
	0x99a is in au8522_probe (drivers/media/dvb-frontends/au8522_decoder.c:761).
	756			printk(KERN_INFO "au8522_decoder attach existing instance.\n");
	757			break;
	758		}
	759
	760		demod_config = kzalloc(sizeof(struct au8522_config), GFP_KERNEL);
	761		if (demod_config == NULL) {
	762			if (instance == 1)
	763				kfree(state);
	764			return -ENOMEM;
	765		}

Shows that the error path is not being handled properly.

The are actually several issues here:

1) config free should have been calling hybrid_tuner_release_state()
function, by calling au8522_release_state();

2) config is only allocated at the digital part. On the analog one,
it is received from the caller.

A complex logic could be added to address it, however, it is simpler
to just embeed config inside the state.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 2 insertions, 12 deletions

diff --git a/drivers/media/dvb-frontends/au8522_decoder.c b/drivers/media/dvb-frontends/au8522_decoder.c
index 28d7dc2fee34..c8f13d8370e5 100644
--- a/drivers/media/dvb-frontends/au8522_decoder.c
+++ b/drivers/media/dvb-frontends/au8522_decoder.c
@@ -730,7 +730,6 @@ static int au8522_probe(struct i2c_client *client,
 	struct v4l2_ctrl_handler *hdl;
 	struct v4l2_subdev *sd;
 	int instance;
-	struct au8522_config *demod_config;
 
 	/* Check if the adapter supports the needed features */
 	if (!i2c_check_functionality(client->adapter,
@@ -754,15 +753,7 @@ static int au8522_probe(struct i2c_client *client,
 		break;
 	}
 
-	demod_config = kzalloc(sizeof(struct au8522_config), GFP_KERNEL);
-	if (demod_config == NULL) {
-		if (instance == 1)
-			kfree(state);
-		return -ENOMEM;
-	}
-	demod_config->demod_address = 0x8e >> 1;
-
-	state->config = demod_config;
+	state->config.demod_address = 0x8e >> 1;
 	state->i2c = client->adapter;
 
 	sd = &state->sd;
@@ -784,8 +775,7 @@ static int au8522_probe(struct i2c_client *client,
 		int err = hdl->error;
 
 		v4l2_ctrl_handler_free(hdl);
-		kfree(demod_config);
-		kfree(state);
+		au8522_release_state(state);
 		return err;
 	}