HID: magicmouse: prevent unbounded recursion in magicmouse_raw_event()
magicmouse_raw_event() handles DOUBLE_REPORT_ID (0xf7) packets, which pack
two touch reports into one, by splitting the packet and calling itself on
each half. The only guard against runaway recursion is a "size < 1" check,
which stops zero-sized calls but does not bound the recursion depth.
A malicious HID device that matches this driver can send a report starting
with DOUBLE_REPORT_ID and filled with the sequence [0xf7, 0x00]. Each level
consumes two bytes and recurses on the remainder, so an incoming report of
up to HID_MAX_BUFFER_SIZE (16 KiB) drives roughly 8000 nested calls. That
easily exhausts the 16 KiB kernel stack, leading to a stack overflow: a
panic with CONFIG_VMAP_STACK, or memory corruption without it.
A double report only ever wraps two normal reports; it is never
legitimately nested. Refuse to re-enter the DOUBLE_REPORT_ID case from a
recursive call so the recursion depth is bounded to two, while all valid
packets keep being parsed exactly as before.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
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Fri, 04 Sep 2026 18:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-674 |
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: magicmouse: prevent unbounded recursion in magicmouse_raw_event() magicmouse_raw_event() handles DOUBLE_REPORT_ID (0xf7) packets, which pack two touch reports into one, by splitting the packet and calling itself on each half. The only guard against runaway recursion is a "size < 1" check, which stops zero-sized calls but does not bound the recursion depth. A malicious HID device that matches this driver can send a report starting with DOUBLE_REPORT_ID and filled with the sequence [0xf7, 0x00]. Each level consumes two bytes and recurses on the remainder, so an incoming report of up to HID_MAX_BUFFER_SIZE (16 KiB) drives roughly 8000 nested calls. That easily exhausts the 16 KiB kernel stack, leading to a stack overflow: a panic with CONFIG_VMAP_STACK, or memory corruption without it. A double report only ever wraps two normal reports; it is never legitimately nested. Refuse to re-enter the DOUBLE_REPORT_ID case from a recursive call so the recursion depth is bounded to two, while all valid packets keep being parsed exactly as before. | |
| Title | HID: magicmouse: prevent unbounded recursion in magicmouse_raw_event() | |
| 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: 2026-09-04T15:12:54.859Z
Reserved: 2026-08-26T14:34:25.792Z
Link: CVE-2026-80783
No data.
Status : Received
Published: 2026-09-04T16:18:04.183
Modified: 2026-09-04T16:18:04.183
Link: CVE-2026-80783
No data.
OpenCVE Enrichment
Updated: 2026-09-04T18:00:04Z