ARM: 9192/1: amba: fix memory leak in amba_device_try_add()

If amba_device_try_add() return error code (not EPROBE_DEFER),
memory leak occurred when amba device fails to read periphid.

unreferenced object 0xc1c60800 (size 1024):
  comm "swapper/0", pid 1, jiffies 4294937333 (age 75.200s)
  hex dump (first 32 bytes):
    40 40 db c1 04 08 c6 c1 04 08 c6 c1 00 00 00 00  @@..............
    00 d9 c1 c1 84 6f 38 c1 00 00 00 00 01 00 00 00  .....o8.........
  backtrace:
    [<(ptrval)>] kmem_cache_alloc_trace+0x168/0x2b4
    [<(ptrval)>] amba_device_alloc+0x38/0x7c
    [<(ptrval)>] of_platform_bus_create+0x2f4/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_populate+0x70/0xc4
    [<(ptrval)>] of_platform_default_populate_init+0xb4/0xcc
    [<(ptrval)>] do_one_initcall+0x58/0x218
    [<(ptrval)>] kernel_init_freeable+0x250/0x29c
    [<(ptrval)>] kernel_init+0x24/0x148
    [<(ptrval)>] ret_from_fork+0x14/0x1c
    [<00000000>] 0x0
unreferenced object 0xc1db4040 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937333 (age 75.200s)
  hex dump (first 32 bytes):
    31 63 30 66 30 30 30 30 2e 77 64 74 00 00 00 00  1c0f0000.wdt....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<(ptrval)>] __kmalloc_track_caller+0x19c/0x2f8
    [<(ptrval)>] kvasprintf+0x60/0xcc
    [<(ptrval)>] kvasprintf_const+0x54/0x78
    [<(ptrval)>] kobject_set_name_vargs+0x34/0xa8
    [<(ptrval)>] dev_set_name+0x40/0x5c
    [<(ptrval)>] of_device_make_bus_id+0x128/0x1f8
    [<(ptrval)>] of_platform_bus_create+0x4dc/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_bus_create+0x380/0x4e8
    [<(ptrval)>] of_platform_populate+0x70/0xc4
    [<(ptrval)>] of_platform_default_populate_init+0xb4/0xcc
    [<(ptrval)>] do_one_initcall+0x58/0x218
    [<(ptrval)>] kernel_init_freeable+0x250/0x29c
    [<(ptrval)>] kernel_init+0x24/0x148
    [<(ptrval)>] ret_from_fork+0x14/0x1c

Fix them by adding amba_device_put() to release device name and
amba device.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 0073d8b..7e775ba 100644 (file)
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -478,8 +478,14 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
                goto skip_probe;
 
        ret = amba_read_periphid(dev);
-       if (ret)
+       if (ret) {
+               if (ret != -EPROBE_DEFER) {
+                       amba_device_put(dev);
+                       goto err_out;
+               }
                goto err_release;
+       }
+
 skip_probe:
        ret = device_add(&dev->dev);
 err_release: