DescriptionIn 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3840-1, DLA-3841-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye (security), bullseye5.10.218-1fixed
bookworm (security)6.1.90-1fixed
sid, trixie6.9.8-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs

Notes (6.8-rc1)

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