CVE-2026-80950: i3c: renesas: Check that the transfer is valid before accessing it

CVE-2026-80950: i3c: renesas: Check that the transfer is valid before accessing it

[Greg Kroah-Hartman]

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

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

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

i3c: renesas: Check that the transfer is valid before accessing it

The Renesas I3C driver uses an asynchronous model to transfer data. It
prepares a struct renesas_i3c_xfer, enqueues it, and waits for completion.
The interrupt handler dequeues the transfer, updates/uses it, and signals
the waiting thread.

If the completion times out, the waiting thread dequeues the transfer and
free it. If an interrupt fires after that, the handler may access freed
memory, leading to crashes.

Check that the transfer is still valid before accessing it in the
interrupt handler. With it clear any status flags and disable all
the interrupts to avoid triggering the same interrupts again.

The Linux kernel CVE team has assigned CVE-2026-80950 to this issue.


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

	Issue introduced in 6.17 with commit d028219a9f1485914492bf373406f6a0e665ace2 and fixed in 6.18.50 with commit 0093f9fc102ba8b98561fdd2f8559553ef56be59
	Issue introduced in 6.17 with commit d028219a9f1485914492bf373406f6a0e665ace2 and fixed in 7.2.4 with commit ec631aff93261c6d031f953549802322032f2aba
	Issue introduced in 6.17 with commit d028219a9f1485914492bf373406f6a0e665ace2 and fixed in 7.3-rc1 with commit 5f1a76ecfe90544a28d657306c9b3caa66ba0e63

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-2026-80950
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/i3c/master/renesas-i3c.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/0093f9fc102ba8b98561fdd2f8559553ef56be59
	https://git.kernel.org/stable/c/ec631aff93261c6d031f953549802322032f2aba
	https://git.kernel.org/stable/c/5f1a76ecfe90544a28d657306c9b3caa66ba0e63