CVE-2026-64279: i2c: core: fix adapter deregistration race

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

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

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

i2c: core: fix adapter deregistration race

Adapters can be looked up by their id using i2c_get_adapter() which
takes a reference to the embedded struct device.

Remove the adapter from the IDR before tearing it down during
deregistration (and on registration failure) to make sure its resources
are not accessed after having been freed (e.g. the device name).

The Linux kernel CVE team has assigned CVE-2026-64279 to this issue.


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

	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 5.15.212 with commit d39282f552dd6c35b9b84b4af78f1198c24f3373
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 6.1.178 with commit 11dfa37bf544cc806f21742ca2fd2d841bd7032e
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 6.6.145 with commit 9882a9bd74db08e7bae5821a7050627ae92d3380
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 6.12.96 with commit bb234487a447a99315add1b46aa57b72e163e1eb
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 6.18.39 with commit b6d2af6fe9c1f5ec0484536753c979cbd40a8ac3
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 7.1.4 with commit 35dbd1f1f603401155cbd3a180bb18e3a3b675b8
	Issue introduced in 2.6.31 with commit 35fc37f8188177e3ba3e7f99a6e3300e490e9181 and fixed in 7.2-rc1 with commit b1a58ed9eab146b36f41a55db8f5d7ce9fdedf3f

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-2026-64279
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/i2c/i2c-core-base.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/d39282f552dd6c35b9b84b4af78f1198c24f3373
	https://git.kernel.org/stable/c/11dfa37bf544cc806f21742ca2fd2d841bd7032e
	https://git.kernel.org/stable/c/9882a9bd74db08e7bae5821a7050627ae92d3380
	https://git.kernel.org/stable/c/bb234487a447a99315add1b46aa57b72e163e1eb
	https://git.kernel.org/stable/c/b6d2af6fe9c1f5ec0484536753c979cbd40a8ac3
	https://git.kernel.org/stable/c/35dbd1f1f603401155cbd3a180bb18e3a3b675b8
	https://git.kernel.org/stable/c/b1a58ed9eab146b36f41a55db8f5d7ce9fdedf3f