• Yang Yingliang's avatar
    driver core: Fix possible memory leak in device_link_add() · df0a1814
    Yang Yingliang authored
    I got memory leak as follows:
    
    unreferenced object 0xffff88801f0b2200 (size 64):
      comm "i2c-lis2hh12-21", pid 5455, jiffies 4294944606 (age 15.224s)
      hex dump (first 32 bytes):
        72 65 67 75 6c 61 74 6f 72 3a 72 65 67 75 6c 61  regulator:regula
        74 6f 72 2e 30 2d 2d 69 32 63 3a 31 2d 30 30 31  tor.0--i2c:1-001
      backtrace:
        [<00000000bf5b0c3b>] __kmalloc_track_caller+0x19f/0x3a0
        [<0000000050da42d9>] kvasprintf+0xb5/0x150
        [<000000004bbbed13>] kvasprintf_const+0x60/0x190
        [<00000000cdac7480>] kobject_set_name_vargs+0x56/0x150
        [<00000000bf83f8e8>] dev_set_name+0xc0/0x100
        [<00000000cc1cf7e3>] device_link_add+0x6b4/0x17c0
        [<000000009db9faed>] _regulator_get+0x297/0x680
        [<00000000845e7f2b>] _devm_regulator_get+0x5b/0xe0
        [<000000003958ee25>] st_sensors_power_enable+0x71/0x1b0 [st_sensors]
        [<000000005f450f52>] st_accel_i2c_probe+0xd9/0x150 [st_accel_i2c]
        [<00000000b5f2ab33>] i2c_device_probe+0x4d8/0xbe0
        [<0000000070fb977b>] really_probe+0x299/0xc30
        [<0000000088e226ce>] __driver_probe_device+0x357/0x500
        [<00000000c21dda32>] driver_probe_device+0x4e/0x140
        [<000000004e650441>] __device_attach_driver+0x257/0x340
        [<00000000cf1891b8>] bus_for_each_drv+0x166/0x1e0
    
    When device_register() returns an error, the name allocated in dev_set_name()
    will be leaked, the put_device() should be used instead of kfree() to give up
    the device reference, then the name will be freed in kobject_cleanup() and the
    references of consumer and supplier will be decreased in device_link_release_fn().
    
    Fixes: 287905e6 ("driver core: Expose device link details in sysfs")
    Reported-by: default avatarHulk Robot <hulkci@huawei.com>
    Reviewed-by: default avatarSaravana Kannan <saravanak@google.com>
    Reviewed-by: default avatarRafael J. Wysocki <rafael@kernel.org>
    Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
    Link: https://lore.kernel.org/r/20210930085714.2057460-1-yangyingliang@huawei.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    df0a1814
core.c 131 KB