Input: evdev - zero absinfo before partial copy in EVIOCSABS
The EVIOCSABS handler copies at most the user supplied ioctl size into
an uninitialized on-stack struct input_absinfo:
if (copy_from_user(&abs, p, min_t(size_t,
size, sizeof(struct input_absinfo))))
The size comes from _IOC_SIZE() of the ioctl command and is therefore
fully controlled by userspace. A short size leaves the trailing part of
the structure holding whatever was on the kernel stack, and the whole
structure is then stored into the device:
dev->absinfo[t] = abs;
EVIOCGABS hands that back to userspace, disclosing the stale stack
bytes. Only the resolution field is currently cleared, which covers the
legacy struct layout but not an arbitrarily short size.
Zero the structure before the copy so any part not supplied by the
caller reads back as zero. The existing resolution fixup is kept, since
it also handles a size that partially overlaps that field.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
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Tue, 06 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-200 |
Tue, 06 Oct 2026 09:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Input: evdev - zero absinfo before partial copy in EVIOCSABS The EVIOCSABS handler copies at most the user supplied ioctl size into an uninitialized on-stack struct input_absinfo: if (copy_from_user(&abs, p, min_t(size_t, size, sizeof(struct input_absinfo)))) The size comes from _IOC_SIZE() of the ioctl command and is therefore fully controlled by userspace. A short size leaves the trailing part of the structure holding whatever was on the kernel stack, and the whole structure is then stored into the device: dev->absinfo[t] = abs; EVIOCGABS hands that back to userspace, disclosing the stale stack bytes. Only the resolution field is currently cleared, which covers the legacy struct layout but not an arbitrarily short size. Zero the structure before the copy so any part not supplied by the caller reads back as zero. The existing resolution fixup is kept, since it also handles a size that partially overlaps that field. | |
| Title | Input: evdev - zero absinfo before partial copy in EVIOCSABS | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-06T08:44:42.563Z
Reserved: 2026-09-25T10:25:14.325Z
Link: CVE-2026-98205
No data.
Status : Received
Published: 2026-10-06T09:18:06.547
Modified: 2026-10-06T09:18:06.547
Link: CVE-2026-98205
No data.
OpenCVE Enrichment
Updated: 2026-10-06T17:15:05Z
-
CWE-200
Exposure of Sensitive Information to an Unauthorized Actor