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

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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>
This commit is contained in:
Mauro Carvalho Chehab
2015-12-21 14:38:31 -02:00
parent c77adf214b
commit aa37763fa4
4 changed files with 16 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/media/dvb-frontends/au8522_common.c
View File

@@ -44,7 +44,7 @@ int au8522_writereg(struct au8522_state *state, u16 reg, u8 data)
int ret;
u8 buf[] = { (reg >> 8) | 0x80, reg & 0xff, data };
struct i2c_msg msg = { .addr = state->config->demod_address,
struct i2c_msg msg = { .addr = state->config.demod_address,
.flags = 0, .buf = buf, .len = 3 };
ret = i2c_transfer(state->i2c, &msg, 1);
@@ -64,9 +64,9 @@ u8 au8522_readreg(struct au8522_state *state, u16 reg)
u8 b1[] = { 0 };
struct i2c_msg msg[] = {
{ .addr = state->config->demod_address, .flags = 0,
{ .addr = state->config.demod_address, .flags = 0,
.buf = b0, .len = 2 },
{ .addr = state->config->demod_address, .flags = I2C_M_RD,
{ .addr = state->config.demod_address, .flags = I2C_M_RD,
.buf = b1, .len = 1 } };
ret = i2c_transfer(state->i2c, msg, 2);
@@ -140,7 +140,7 @@ EXPORT_SYMBOL(au8522_release_state);
static int au8522_led_gpio_enable(struct au8522_state *state, int onoff)
{
struct au8522_led_config *led_config = state->config->led_cfg;
struct au8522_led_config *led_config = state->config.led_cfg;
u8 val;
/* bail out if we can't control an LED */
@@ -170,7 +170,7 @@ static int au8522_led_gpio_enable(struct au8522_state *state, int onoff)
*/
int au8522_led_ctrl(struct au8522_state *state, int led)
{
struct au8522_led_config *led_config = state->config->led_cfg;
struct au8522_led_config *led_config = state->config.led_cfg;
int i, ret = 0;
/* bail out if we can't control an LED */