Executive brief
The Linux kernel's Synaptics RMI4 touchpad/pointing device driver contains a heap buffer overflow vulnerability in its F54 diagnostics function. When an error occurs during report processing, stale payload size information is retained and later used to copy data into a smaller buffer, causing memory corruption. An attacker with local access to the system could exploit this to crash the kernel or potentially execute arbitrary code.
Technical details
The vulnerability exists in the rmi_f54_work() function within drivers/input/rmi4/rmi_f54.c. When an error occurs during report request or command verification, the code jumps to an 'error' label that bypassed the 'abort' label where f54->report_size was normally zeroed. This left f54->report_size containing a previous successful payload size. If a user then altered the V4L2 format to a smaller size and a subsequent run failed, rmi_f54_buffer_queue() would copy the stale, larger payload size into the shrunken V4L2 buffer, causing a heap overflow. The fix merges the 'abort' and 'error' labels into a single 'out' exit path, ensuring f54->report_size is always zeroed on error. Local code execution preconditions: user must have access to trigger format changes and diagnostics operations. Patches are available in upstream Linux kernel and stable branches.
Affected products
- Linux Linux kernel affected versions prior to fix commit dc76c3c8e8ad09362b8c1561f3928288c15cba2e
Timeline
- 2026-08-26: disclosed: CVE-2026-80570 published
- 2026-06-25: patched: Fix committed by Dmitry Torokhov; merged into stable branches
- 2026-08-23: other: Backported to stable Linux kernel releases