CVE-2026-64351

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

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

kalmiarxfixup() computes usbpacketlength = skb->len - (2 * KALMIAHEADERLENGTH) as a u16, guarded only by a pre-loop check that skb->len is at least KALMIAHEADERLENGTH, 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 usbpacketlength to about 65530.

That bypasses the usbpacketlength < etherpacketlength truncation path. The device-supplied etherpacketlength, a le16 up to 65535 read from headerstart[2], then drives a memcmp() and the following skbtrim() and skbpull() past the end of the rx buffer. The rx buffer is hardmtu * 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.