In the Linux kernel, the following vulnerability has been resolved:
HID: core: fix OOB read of field->usage in hid_set_field()
hid_set_field() hands field->usage + offset to hid_dump_input() before
the guard that bounds offset:
hid_dump_input(field->report->device, field->usage + offset, value);
if (offset >= field->report_count) {
hid_err(...);
return -1;
}
Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with
buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is
allocated inline with the hid_field in hid_register_field() and holds
field->maxusage entries, so an offset past it reads off the end of the
kvzalloc()ed allocation and into a neighbouring object. Had the guard
run first, offset < report_count <= maxusage would already have confined
the pointer to the array.
A caller supplies such an offset today. picolcd_fb_send_tile()
validates only report->maxfield before issuing
hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its
offsets are fixed at 11..42 and are never checked against the bound
field. When the device registers that field with fewer usages, the
framebuffer deferred-io work drives the read on every tile. KASAN
reports a 4-byte slab-out-of-bounds read in hid_dump_input() below
hid_set_field(), and the same boot logs "offset (1) exceeds
report_count (1)" from the guard that runs only afterwards.
Move the hid_dump_input() call below the guard. Because
field->maxusage >= field->report_count, the guard then establishes that
field->usage + offset lies inside the array before it is dereferenced,
for every caller and without changing behaviour on the valid path.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
HID: core: fix OOB read of field->usage in hid_set_field()
hid_set_field() hands field->usage + offset to hid_dump_input() before
the guard that bounds offset:
hid_dump_input(field->report->device, field->usage + offset, value);
if (offset >= field->report_count) {
hid_err(...);
return -1;
}
Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with
buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is
allocated inline with the hid_field in hid_register_field() and holds
field->maxusage entries, so an offset past it reads off the end of the
kvzalloc()ed allocation and into a neighbouring object. Had the guard
run first, offset < report_count <= maxusage would already have confined
the pointer to the array.
A caller supplies such an offset today. picolcd_fb_send_tile()
validates only report->maxfield before issuing
hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its
offsets are fixed at 11..42 and are never checked against the bound
field. When the device registers that field with fewer usages, the
framebuffer deferred-io work drives the read on every tile. KASAN
reports a 4-byte slab-out-of-bounds read in hid_dump_input() below
hid_set_field(), and the same boot logs "offset (1) exceeds
report_count (1)" from the guard that runs only afterwards.
Move the hid_dump_input() call below the guard. Because
field->maxusage >= field->report_count, the guard then establishes that
field->usage + offset lies inside the array before it is dereferenced,
for every caller and without changing behaviour on the valid path.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 04 Sep 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: HID: core: fix OOB read of field->usage in hid_set_field() hid_set_field() hands field->usage + offset to hid_dump_input() before the guard that bounds offset: hid_dump_input(field->report->device, field->usage + offset, value); if (offset >= field->report_count) { hid_err(...); return -1; } Under CONFIG_DEBUG_FS hid_dump_input() dereferences that pointer, with buf = hid_resolv_usage(usage->hid, NULL). The usage[] array is allocated inline with the hid_field in hid_register_field() and holds field->maxusage entries, so an offset past it reads off the end of the kvzalloc()ed allocation and into a neighbouring object. Had the guard run first, offset < report_count <= maxusage would already have confined the pointer to the array. A caller supplies such an offset today. picolcd_fb_send_tile() validates only report->maxfield before issuing hid_set_field(report->field[0], 11 + i, ...) for i = 0..31, so its offsets are fixed at 11..42 and are never checked against the bound field. When the device registers that field with fewer usages, the framebuffer deferred-io work drives the read on every tile. KASAN reports a 4-byte slab-out-of-bounds read in hid_dump_input() below hid_set_field(), and the same boot logs "offset (1) exceeds report_count (1)" from the guard that runs only afterwards. Move the hid_dump_input() call below the guard. Because field->maxusage >= field->report_count, the guard then establishes that field->usage + offset lies inside the array before it is dereferenced, for every caller and without changing behaviour on the valid path. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> | |
| Title | HID: core: fix OOB read of field->usage in hid_set_field() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-04T15:12:52.980Z
Reserved: 2026-08-26T14:34:25.792Z
Link: CVE-2026-80781
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-04T16:18:03.867
Modified: 2026-09-04T16:18:03.867
Link: CVE-2026-80781
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.