CVE-2026-64351

/// Technical 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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References