CVE-2026-64351: net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()

CVE-2026-64351: net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()

[Greg Kroah-Hartman]

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

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

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

net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()

kalmia_rx_fixup() computes usb_packet_length = skb->len - (2 *
KALMIA_HEADER_LENGTH) as a u16, guarded only by a pre-loop check that
skb->len is at least KALMIA_HEADER_LENGTH, which is 6. A device can
deliver a short bulk-IN frame with skb->len in the 6 to 11 range, or
leave a short trailing remainder on a later loop iteration. Either case
underflows usb_packet_length to about 65530.

That bypasses the usb_packet_length < ether_packet_length truncation path.
The device-supplied ether_packet_length, a le16 up to 65535 read from
header_start[2], then drives a memcmp() and the following skb_trim() and
skb_pull() past the end of the rx buffer. The rx buffer is hard_mtu * 10,
which is 14000 bytes. That is an out of bounds read.

Require both the start and end framing headers to be present before
subtracting them, on every loop iteration.

The Linux kernel CVE team has assigned CVE-2026-64351 to this issue.


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

	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 5.10.261 with commit 391706889a5112feafdc0c68db3ecc7ed325d09c
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 5.15.212 with commit aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 6.1.178 with commit 2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 6.6.145 with commit 46ab32870d010e9a057bc5659cea22b7e728ca88
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 6.12.96 with commit c466097d85d52f3aa200736cb4759e66d4bbf6e3
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 6.18.39 with commit e24eb271061db384a3c3ef6f107fe515e68ef222
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 7.1.4 with commit 51e65f1d78457ea4f9513d90ab22c9dccbb35110
	Issue introduced in 3.0 with commit d40261236e8e278cb1936cb5e934262971692b10 and fixed in 7.2-rc1 with commit 47b6bcef6e679593d2e86e04ee72c46a4e2f7139

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-2026-64351
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/usb/kalmia.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/391706889a5112feafdc0c68db3ecc7ed325d09c
	https://git.kernel.org/stable/c/aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b
	https://git.kernel.org/stable/c/2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a
	https://git.kernel.org/stable/c/46ab32870d010e9a057bc5659cea22b7e728ca88
	https://git.kernel.org/stable/c/c466097d85d52f3aa200736cb4759e66d4bbf6e3
	https://git.kernel.org/stable/c/e24eb271061db384a3c3ef6f107fe515e68ef222
	https://git.kernel.org/stable/c/51e65f1d78457ea4f9513d90ab22c9dccbb35110
	https://git.kernel.org/stable/c/47b6bcef6e679593d2e86e04ee72c46a4e2f7139