CVE-2026-74457: can: peak_usb: add bounds check for USB channel index

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

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

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

can: peak_usb: add bounds check for USB channel index

The channel control index ctrl_idx is derived from rx->len which comes
directly from a device USB payload. The mask 0x0f allows values 0-15, but
the array size of usb_if->dev[] is only 2. Values 2-15 cause heap
out-of-bounds read, eventually causing kernel panic in the IRQ context.

Add bounds checking for ctrl_idx before the array access in both
pcan_usb_pro_handle_canmsg() and pcan_usb_pro_handle_error().

The Linux kernel CVE team has assigned CVE-2026-74457 to this issue.


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

	Issue introduced in 3.4 with commit d8a199355f8f8a0797c00d98788d7282c9ea38bd and fixed in 6.6.151 with commit 825c903ca3c98cd0cf0e3de8ab8f2604a5339b3f
	Issue introduced in 3.4 with commit d8a199355f8f8a0797c00d98788d7282c9ea38bd and fixed in 6.12.103 with commit f97b7e5e1cdaae15cd95b3a360028c7929664969
	Issue introduced in 3.4 with commit d8a199355f8f8a0797c00d98788d7282c9ea38bd and fixed in 6.18.44 with commit 1acab790b7cecd4e144d1d18bdfe549e282f6b0b
	Issue introduced in 3.4 with commit d8a199355f8f8a0797c00d98788d7282c9ea38bd and fixed in 7.1.8 with commit 0149fdb50a30944827acf9600a2cc44de0325a7f
	Issue introduced in 3.4 with commit d8a199355f8f8a0797c00d98788d7282c9ea38bd and fixed in 7.2-rc6 with commit 39132f166ca8ce00ae60d8a9068e06a60943cc4b

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-2026-74457
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/net/can/usb/peak_usb/pcan_usb_pro.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/825c903ca3c98cd0cf0e3de8ab8f2604a5339b3f
	https://git.kernel.org/stable/c/f97b7e5e1cdaae15cd95b3a360028c7929664969
	https://git.kernel.org/stable/c/1acab790b7cecd4e144d1d18bdfe549e282f6b0b
	https://git.kernel.org/stable/c/0149fdb50a30944827acf9600a2cc44de0325a7f
	https://git.kernel.org/stable/c/39132f166ca8ce00ae60d8a9068e06a60943cc4b