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.
Affected products
linux: linux kernel
References8
- git.kernel.org/stable/c/2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a Patch
- git.kernel.org/stable/c/391706889a5112feafdc0c68db3ecc7ed325d09c Patch
- git.kernel.org/stable/c/46ab32870d010e9a057bc5659cea22b7e728ca88 Patch
- git.kernel.org/stable/c/47b6bcef6e679593d2e86e04ee72c46a4e2f7139 Patch
- git.kernel.org/stable/c/51e65f1d78457ea4f9513d90ab22c9dccbb35110 Patch
- git.kernel.org/stable/c/aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b Patch
- git.kernel.org/stable/c/c466097d85d52f3aa200736cb4759e66d4bbf6e3 Patch
- git.kernel.org/stable/c/e24eb271061db384a3c3ef6f107fe515e68ef222 Patch
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 3 · as of 14 November 2026
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