CVE-2023-52439 Information

Feb 21, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

uio: Fix use-after-free in uio_open

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.

Reference

https://git.kernel.org/stable/c/3174e0f7de1ba392dc191625da83df02d695b60c https://git.kernel.org/stable/c/e93da893d52d82d57fc0db2ca566024e0f26ff50 https://git.kernel.org/stable/c/5e0be1229ae199ebb90b33102f74a0f22d152570 https://git.kernel.org/stable/c/5cf604ee538ed0c467abe3b4cda5308a6398f0f7 https://git.kernel.org/stable/c/17a8519cb359c3b483fb5c7367efa9a8a508bdea https://git.kernel.org/stable/c/35f102607054faafe78d2a6994b18d5d9d6e92ad https://git.kernel.org/stable/c/913205930da6213305616ac539447702eaa85e41 https://git.kernel.org/stable/c/0c9ae0b8605078eafc3bea053cc78791e97ba2e2

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