Description
In the Linux kernel, the following vulnerability has been resolved:
Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size
nexio_read_data() pulls data_len and x_len from a packed __be16 header
in the device's interrupt packet and then walks packet->data[0..x_len)
and packet->data[x_len..data_len) comparing each byte against a
threshold.
Both fields are 16-bit on the wire (max 65535). The existing
adjustments shave at most 0x100 / 0x80 off, so the loop bound can still
reach roughly 0xfeff. The URB transfer buffer for NEXIO is rept_size
(1024) bytes from usb_alloc_coherent(), with the first 7 occupied by the
packed header — so packet->data[] has 1017 valid bytes. read_data()
callbacks are not given urb->actual_length, and nothing else bounds the
walk.
A device that lies about its length can get a ~64 KiB out-of-bounds read
past the coherent DMA allocation. The first index whose byte exceeds
NEXIO_THRESHOLD lands in begin_x / begin_y and from there into the
reported touch coordinates, so adjacent kernel memory contents leak to
userspace as ABS_X / ABS_Y events. Far enough out, the read can also
hit an unmapped page and fault.
Fix this all by clamping data_len to the buffer's data[] capacity and
x_len to data_len.
Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size
nexio_read_data() pulls data_len and x_len from a packed __be16 header
in the device's interrupt packet and then walks packet->data[0..x_len)
and packet->data[x_len..data_len) comparing each byte against a
threshold.
Both fields are 16-bit on the wire (max 65535). The existing
adjustments shave at most 0x100 / 0x80 off, so the loop bound can still
reach roughly 0xfeff. The URB transfer buffer for NEXIO is rept_size
(1024) bytes from usb_alloc_coherent(), with the first 7 occupied by the
packed header — so packet->data[] has 1017 valid bytes. read_data()
callbacks are not given urb->actual_length, and nothing else bounds the
walk.
A device that lies about its length can get a ~64 KiB out-of-bounds read
past the coherent DMA allocation. The first index whose byte exceeds
NEXIO_THRESHOLD lands in begin_x / begin_y and from there into the
reported touch coordinates, so adjacent kernel memory contents leak to
userspace as ABS_X / ABS_Y events. Far enough out, the read can also
hit an unmapped page and fault.
Fix this all by clamping data_len to the buffer's data[] capacity and
x_len to data_len.
Published:
2026-07-19
Score:
n/a
EPSS:
< 1% Very Low
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sun, 19 Jul 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size nexio_read_data() pulls data_len and x_len from a packed __be16 header in the device's interrupt packet and then walks packet->data[0..x_len) and packet->data[x_len..data_len) comparing each byte against a threshold. Both fields are 16-bit on the wire (max 65535). The existing adjustments shave at most 0x100 / 0x80 off, so the loop bound can still reach roughly 0xfeff. The URB transfer buffer for NEXIO is rept_size (1024) bytes from usb_alloc_coherent(), with the first 7 occupied by the packed header — so packet->data[] has 1017 valid bytes. read_data() callbacks are not given urb->actual_length, and nothing else bounds the walk. A device that lies about its length can get a ~64 KiB out-of-bounds read past the coherent DMA allocation. The first index whose byte exceeds NEXIO_THRESHOLD lands in begin_x / begin_y and from there into the reported touch coordinates, so adjacent kernel memory contents leak to userspace as ABS_X / ABS_Y events. Far enough out, the read can also hit an unmapped page and fault. Fix this all by clamping data_len to the buffer's data[] capacity and x_len to data_len. | |
| Title | Input: usbtouchscreen - clamp NEXIO data_len/x_len to URB buffer size | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-19T14:56:27.995Z
Reserved: 2026-07-19T07:54:57.027Z
Link: CVE-2026-64014
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.