CVE-2026-64547

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

net: usb: net1080: validate packet_len before pad-byte access in rx_fixup

For an even packet_len, net1080_rx_fixup() reads the pad byte at skb->data[packet_len] before the skb->len != packet_len check further down, and packet_len is only bounded against NC_MAX_PACKET. A malicious NetChip 1080 device can send a short frame advertising a large even packet_len (e.g. 0x4000), so the pad-byte read lands past the end of the skb:

BUG: KASAN: slab-out-of-bounds in net1080_rx_fixup Read of size 1 at addr ffff8880106c83c6 by task ksoftirqd/0/14 … net1080_rx_fixup (drivers/net/usb/net1080.c:384) usbnet_bh (drivers/net/usb/usbnet.c:1589) process_one_work (kernel/workqueue.c:3322) bh_worker (kernel/workqueue.c:3708) tasklet_action (kernel/softirq.c:965) handle_softirqs (kernel/softirq.c:622) …

Reject the frame when packet_len >= skb->len before reading.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/03f384bc0cb8d4a1301d4f5b0baef2d980258383
• https://git.kernel.org/stable/c/4dc8484be3302d187274364820d3bef6c62bde32
• https://git.kernel.org/stable/c/685e92934f11d5e215dad58813e2f9955ac2f436
• https://git.kernel.org/stable/c/b153cfe84b1340c69a13d0957665a2bfcf21239c
• https://git.kernel.org/stable/c/c087749815379e9af2fdbeb08bfc33870b103958
• https://git.kernel.org/stable/c/e4a87126c085b097d29e17e3b7647295bba8be7c
• https://git.kernel.org/stable/c/ea866cab12db1a2100b400a8b03569e5bc0ee29a
• https://git.kernel.org/stable/c/f42217fa7d535e9ec4151f7971f06f6ea65e850a