Subject: CVE-2023-52898: xhci: Fix null pointer dereference when host dies

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

xhci: Fix null pointer dereference when host dies

Make sure xhci_free_dev() and xhci_kill_endpoint_urbs() do not race
and cause null pointer dereference when host suddenly dies.

Usb core may call xhci_free_dev() which frees the xhci->devs[slot_id]
virt device at the same time that xhci_kill_endpoint_urbs() tries to
loop through all the device's endpoints, checking if there are any
cancelled urbs left to give back.

hold the xhci spinlock while freeing the virt device

The Linux kernel CVE team has assigned CVE-2023-52898 to this issue.

Affected and fixed versions
===========================

	Fixed in 4.19.271 with commit 6fac4b5cecb3
	Fixed in 5.4.230 with commit 133b902378e4
	Fixed in 5.10.165 with commit 081105213ff6
	Fixed in 5.15.90 with commit c462ac871f49
	Fixed in 6.1.8 with commit ea2ee5e9991c
	Fixed in 6.2 with commit a2bc47c43e70

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-52898
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/usb/host/xhci.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/6fac4b5cecb3928a0a81069aaa815a2edc8dd5a1
	https://git.kernel.org/stable/c/133b902378e4acbd824c29dd0d48570ad596e368
	https://git.kernel.org/stable/c/081105213ff6f661c114781d469233c7d0e09c2e
	https://git.kernel.org/stable/c/c462ac871f49753eca86bb960f573b993976a5ea
	https://git.kernel.org/stable/c/ea2ee5e9991caf74e0604f994c1831a5867055b2
	https://git.kernel.org/stable/c/a2bc47c43e70cf904b1af49f76d572326c08bca7