35f1026070
commit 0c9ae0b8605078eafc3bea053cc78791e97ba2e2 upstream.
core-1 core-2
-------------------------------------------------------
uio_unregister_device uio_open
idev = idr_find()
device_unregister(&idev->dev)
put_device(&idev->dev)
uio_device_release
get_device(&idev->dev)
kfree(idev)
uio_free_minor(minor)
uio_release
put_device(&idev->dev)
kfree(idev)
-------------------------------------------------------
In the core-1 uio_unregister_device(), the device_unregister will kfree
idev when the idev->dev kobject ref is 1. But after core-1
device_unregister, put_device and before doing kfree, the core-2 may
get_device. Then:
1. After core-1 kfree idev, the core-2 will do use-after-free for idev.
2. When core-2 do uio_release and put_device, the idev will be double
freed.
To address this issue, we can get idev atomic & inc idev reference with
minor_lock.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| uio.c | ||
| uio_aec.c | ||
| uio_cif.c | ||
| uio_dfl.c | ||
| uio_dmem_genirq.c | ||
| uio_fsl_elbc_gpcm.c | ||
| uio_hv_generic.c | ||
| uio_mf624.c | ||
| uio_netx.c | ||
| uio_pci_generic.c | ||
| uio_pdrv_genirq.c | ||
| uio_pruss.c | ||
| uio_sercos3.c | ||