CVE-2026-64277

In the Linux kernel, the following vulnerability has been resolved:

Input: synaptics-rmi4 - bound the F3A keymap to the GPIO count

rmi_f3a_initialize() takes the GPIO count from the device query register (f3a->gpio_count = buf & RMI_F3A_GPIO_COUNT, range 0..127). rmi_f3a_map_gpios() then allocates gpio_key_map with min(gpio_count, TRACKSTICK_RANGE_END) == at most 6 entries, but rmi_f3a_attention() iterates the full gpio_count and dereferences gpio_key_map[i], and input->keycodemax is set to the full gpio_count while input->keycode points at the 6-entry allocation.

A device that reports gpio_count > 6 therefore causes an out-of-bounds read of gpio_key_map[] on every attention interrupt, and out-of-bounds accesses through the input cores default keymap ioctls: EVIOCGKEYCODE reads past the buffer (leaking adjacent slab memory to user space) and EVIOCSKEYCODE writes a caller-controlled value past it, for any process able to open the evdev node, since input_default_getkeycode() and input_default_setkeycode() only bound the index against keycodemax.

Size the keymap for the full gpio_count. The mapping loop is unchanged: it still assigns only the first min(gpio_count, TRACKSTICK_RANGE_END) entries; the remaining slots stay KEY_RESERVED (devm_kcalloc zero-fills) and are skipped when reporting.

Affected Software

References

• https://git.kernel.org/stable/c/3480e24bc4e178aaa009edb25b6ee12df199e210
• https://git.kernel.org/stable/c/35ed74d32d8260bdfb14a94caf402bf0866bdeec
• https://git.kernel.org/stable/c/502ad7caaa1a445b734c827fa256e5311df67e3d
• https://git.kernel.org/stable/c/57c10915f2c16c90e0d46ad00876bf39ece40fc2
• https://git.kernel.org/stable/c/64fb0e1161ccc6b9e48b8df61f07d3c34c01ec42
• https://git.kernel.org/stable/c/850117b637bcb1dcc14be0cf09ac819a8707b42c
• https://git.kernel.org/stable/c/8db211aed83733073b0814adaeeab61d4521474e
• https://git.kernel.org/stable/c/ba57f430328534501962d60d651e385ffd7af9ca