| Message ID | 20221123081643.713184-1-lizetao1@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: core: Fix possible memleak in i2c_register_adapter() | expand |
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 5dcea9f1deab..ef85e58533e2 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1472,6 +1472,9 @@ static int i2c_register_adapter(struct i2c_adapter *adap) res = device_register(&adap->dev); if (res) { pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); + init_completion(&adap->dev_released); + put_device(&adap->dev); + wait_for_completion(&adap->dev_released); goto out_list; }
I got memory leak as follows when doing fault injection test: unreferenced object 0xffff88818be6dcb8 (size 8): comm "modprobe", pid 1022129, jiffies 4363911608 (age 43.838s) hex dump (first 8 bytes): 69 32 63 2d 30 00 6b a5 i2c-0.k. backtrace: [<ffffffff812f588f>] __kmem_cache_alloc_node+0x2cf/0x4b0 [<ffffffff81283c43>] __kmalloc_node_track_caller+0x53/0x140 [<ffffffff81604b0a>] kvasprintf+0x6a/0xd0 [<ffffffff81604be7>] kvasprintf_const+0x77/0xa0 [<ffffffff81a00173>] kobject_set_name_vargs+0x23/0x90 [<ffffffff817bf743>] dev_set_name+0x53/0x70 [<ffffffffa023ebb2>] i2c_register_adapter+0x112/0x6c0 [i2c_core] [<ffffffffa023f268>] i2c_add_adapter+0x78/0xc0 [i2c_core] [<ffffffffa0300182>] piix4_add_adapter+0x132/0x210 [i2c_piix4] [<ffffffffa0300535>] piix4_probe+0x2d5/0x5f4 [i2c_piix4] [<ffffffff816c5da2>] pci_device_probe+0xb2/0x180 [<ffffffff817c769f>] really_probe+0xff/0x380 [<ffffffff817c79aa>] __driver_probe_device+0x8a/0x190 [<ffffffff817c7b33>] driver_probe_device+0x23/0xb0 [<ffffffff817c80a3>] __driver_attach+0xd3/0x1b0 [<ffffffff817c4ede>] bus_for_each_dev+0x7e/0xd0 The root cause was traced to an error handing path in i2c_register_adapter() when device_register() fails. After calling dev_set_name() which called by i2c_register_adapter(), the put_device() should be used to give up the device reference in error handling path in order to free "kobj->name" alloced in dev_set_name(). Fix it by calling put_device() when device_register() fails in i2c_register_adapter(). In addition, when i2c_adapter device is released, i2c_adapter_dev_release() is called, in which "dev_released" must be initialized, otherwise a kernel bug will be triggered. Fixes: b119c6c952a0 ("i2c: __must_check fixes (core drivers)") Signed-off-by: Li Zetao <lizetao1@huawei.com> --- drivers/i2c/i2c-core-base.c | 3 +++ 1 file changed, 3 insertions(+)