CVE-2026-19576
6.8MediumPublished 11 Oct 2026 · NVD status: Awaiting Analysis · AI triage by gemini-3.8-flash
- Attack vector
- Physical
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- Full C/I/A compromise
- Weakness
- CWE-787
Impact
An attacker with physical access can hijack control flow and execute code at kernel privilege by attaching a rogue or modified I2C touch controller. Uncontrolled touch point reporting can also trigger kernel crashes non-adversarially via bus corruption or incompatible hardware.
Root cause
The Goodix GT9xx driver fails to bound the hardware-reported touch point count against the smaller, stack-allocated point_reg array before copying I2C data into it.
Affected systems
Zephyr RTOS using the GT9xx driver (drivers/input/input_gt911.c); exact release versions are not listed — check the vendor advisory.
CVSS v3.1 · CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Fix & remediation
Apply commit 42b52d571eb2113012c135276693042fd372fdea to clamp the touch count with min() against CONFIG_INPUT_GT911_MAX_TOUCH_POINTS. If patching immediately is not possible, disable the GT911 driver in your build configuration by setting CONFIG_INPUT_GT911=n.
AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
The Goodix GT9xx input driver in drivers/input/input_gt911.c reads the touch point count from the controller's status register and masks it with GT911_TOUCH_POINTS_MSK (0x0F), yielding a value of 0..15. In gt911_process() that value is used directly as the loop bound for filling point_reg[], a stack array sized to CONFIG_INPUT_GT911_MAX_TOUCH_POINTS, whose Kconfig range is 1..5 with a default of 1. No other check constrains the count; the driver relied only on a comment asserting that the controller had been programmed at init to report no more points than configured. Each loop iteration issues an I2C read of eight bytes straight into point_reg[i], so a controller that reports more points than the array holds causes up to 112 bytes of peer-supplied data to be written past the end of the array, over the stack frame of gt911_process() in the system workqueue thread. Two further loops then read out of bounds from the same array. Triggering it requires control of, or the ability to substitute, the I2C touch controller — plausible on the many supported boards where the GT9xx panel is a pluggable display module or shield rather than an on-PCB part; a spoofed device need only answer the init probes with a supported product ID and a checksum-valid config blob. The same overflow can also occur non-adversarially, with a GT9271-class panel that ignores the driver's touch-count programming and reports up to ten points, or with bus corruption of the single status byte. The impact is an out-of-bounds stack write with fully attacker-chosen content executing at kernel privilege, i.e. potential control-flow hijack on the host MCU, in addition to out-of-bounds reads and crashes. The attack vector is physical/local hardware access only; there is no network, USB, or syscall path to the defect. The fix clamps the reported count with min() against CONFIG_INPUT_GT911_MAX_TOUCH_POINTS before any array indexing.