From: Yang Yingliang <yangyingliang@xxxxxxxxxx>
commit efa17e90e1711bdb084e3954fa44afb6647331c0 upstream.
dev_set_name() allocates memory for name, it need be freed
when device_add() fails, call put_device() to give up the
reference that hold in device_initialize(), so that it can
be freed in kobject_cleanup() when the refcount hit to 0.
Fault injection test can trigger this:
unreferenced object 0xffff8e8340a7b4c0 (size 32):
comm "modprobe", pid 243, jiffies 4294678145 (age 48.845s)
hex dump (first 32 bytes):
69 69 6f 5f 73 79 73 66 73 5f 74 72 69 67 67 65 iio_sysfs_trigge
72 00 a7 40 83 8e ff ff 00 86 13 c4 f6 ee ff ff r..@............
backtrace:
[<0000000074999de8>] __kmem_cache_alloc_node+0x1e9/0x360
[<00000000497fd30b>] __kmalloc_node_track_caller+0x44/0x1a0
[<000000003636c520>] kstrdup+0x2d/0x60
[<0000000032f84da2>] kobject_set_name_vargs+0x1e/0x90
[<0000000092efe493>] dev_set_name+0x4e/0x70
Fixes: 1f785681a870 ("staging:iio:trigger sysfs userspace trigger rework.")
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221022074212.1386424-1-yangyingliang@xxxxxxxxxx
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/trigger/iio-trig-sysfs.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/iio/trigger/iio-trig-sysfs.c
+++ b/drivers/iio/trigger/iio-trig-sysfs.c
@@ -209,9 +209,13 @@ static int iio_sysfs_trigger_remove(int
static int __init iio_sysfs_trig_init(void)
{
+ int ret;
device_initialize(&iio_sysfs_trig_dev);
dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger");
- return device_add(&iio_sysfs_trig_dev);
+ ret = device_add(&iio_sysfs_trig_dev);
+ if (ret)
+ put_device(&iio_sysfs_trig_dev);
+ return ret;
}
module_init(iio_sysfs_trig_init);
