CVE-2026-90020: USB: gadget: fix NULL pointer dereference in gadget_dev_ioctl()

CVE-2026-90020: USB: gadget: fix NULL pointer dereference in gadget_dev_ioctl()

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

USB: gadget: fix NULL pointer dereference in gadget_dev_ioctl()

gadget_dev_ioctl() reads dev->gadget before acquiring dev->lock, but
dev->state is checked after acquiring the lock. Therefore a concurrent
bind can change the device state between these operations, which can
leave ioctl with a stale NULL gadget pointer and causing a NULL pointer
dereference at gadget->ops->ioctl.

Read dev->gadget while holding dev->lock so that the gadget pointer
and device state are sampled consistently.

The Linux kernel CVE team has assigned CVE-2026-90020 to this issue.


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

	Fixed in 5.10.270 with commit 8be30959be31b4205e3bdd2e2a6221f3a2ee7ea1
	Fixed in 5.15.221 with commit e8219accce2f6d3502ed71f5b5e854ecf27249a6
	Fixed in 6.1.188 with commit 87cbf9410b12f5c2d659bb01e8ecf6517cb9f28c
	Fixed in 6.6.157 with commit 162178ca83c3de986900385a0477eb539f8e1a7e
	Fixed in 6.12.110 with commit ebd916fdfefaacbc0e577f7037ec96b31a105e5f
	Fixed in 6.18.51 with commit c29a83c1ff3f06d5751f6d365b606c9f81ccc4cb
	Fixed in 7.2.5 with commit 64ec019bf9a8b12f53b9f2777d65aadb730b5a84
	Fixed in 7.3-rc2 with commit dd0eed9e165b1a6292f49e622e3dd0b7d99b106d

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-2026-90020
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/gadget/legacy/inode.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/8be30959be31b4205e3bdd2e2a6221f3a2ee7ea1
	https://git.kernel.org/stable/c/e8219accce2f6d3502ed71f5b5e854ecf27249a6
	https://git.kernel.org/stable/c/87cbf9410b12f5c2d659bb01e8ecf6517cb9f28c
	https://git.kernel.org/stable/c/162178ca83c3de986900385a0477eb539f8e1a7e
	https://git.kernel.org/stable/c/ebd916fdfefaacbc0e577f7037ec96b31a105e5f
	https://git.kernel.org/stable/c/c29a83c1ff3f06d5751f6d365b606c9f81ccc4cb
	https://git.kernel.org/stable/c/64ec019bf9a8b12f53b9f2777d65aadb730b5a84
	https://git.kernel.org/stable/c/dd0eed9e165b1a6292f49e622e3dd0b7d99b106d