CVE-2026-64464: xhci: sideband: fix ring sg table pages leak

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

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

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

xhci: sideband: fix ring sg table pages leak

xhci_ring_to_sgtable() allocates a temporary pages array and
uses it to build the returned sg_table with
sg_alloc_table_from_pages().

The error paths free the pages array, but the success path
returns the sg_table without freeing it. This leaks the temporary
array every time a sideband client gets an endpoint or event ring
buffer.

Free the pages array after sg_alloc_table_from_pages() succeeds.
The returned sg_table has its own scatterlist entries and does not
depend on the temporary array after construction.

The Linux kernel CVE team has assigned CVE-2026-64464 to this issue.


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

	Issue introduced in 6.16 with commit de66754e9f8029f8ae955a588959b99cab56b506 and fixed in 6.18.39 with commit 99d00a9e35e311a91d258029d5bb584377296c34
	Issue introduced in 6.16 with commit de66754e9f8029f8ae955a588959b99cab56b506 and fixed in 7.1.4 with commit a3eaf82ff842d6ca95937ea584417e04828235a6
	Issue introduced in 6.16 with commit de66754e9f8029f8ae955a588959b99cab56b506 and fixed in 7.2-rc3 with commit 49f6e3c3ef19f04f6657ed8dce550e36c763abb8

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-2026-64464
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-sideband.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/99d00a9e35e311a91d258029d5bb584377296c34
	https://git.kernel.org/stable/c/a3eaf82ff842d6ca95937ea584417e04828235a6
	https://git.kernel.org/stable/c/49f6e3c3ef19f04f6657ed8dce550e36c763abb8