In the Linux kernel, the following vulnerability has been resolved: iio: gyro: itg3200: fix i2c read into the wrong stack location itg3200_read_all_channels() takes `__be16 *buf' as a parameter and fills the i2c_msg destination as `(char *)&buf'. Since `buf' is the parameter (a pointer), `&buf' is the address of the local pointer slot on the stack of itg3200_read_all_channels(), not the address of the caller's scan buffer. The (char *) cast hides the type mismatch. i2c_transfer() therefore wr
In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: itg3200: fix i2c read into the wrong stack location
itg3200_read_all_channels() takes __be16 *buf' as a parameter and fills the i2c_msg destination as (char *)&buf'. Since buf' is the parameter (a pointer), &buf' is the address of the local pointer
slot on the stack of itg3200_read_all_channels(), not the address
of the caller's scan buffer. The (char *) cast hides the type
mismatch.
i2c_transfer() therefore writes ITG3200_SCAN_ELEMENTS * sizeof(s16) = 8 bytes into the parameter's stack slot, which is discarded when the function returns. The caller's scan buffer in itg3200_trigger_handler() is never written to, so iio_push_to_buffers_with_timestamp() pushes uninitialised stack contents to userspace via /dev/iio:deviceX every scan -- both a functional bug (no actual gyroscope or temperature data is delivered through the triggered buffer) and an information leak.
The non-buffered read_raw() path is unaffected: it goes through itg3200_read_reg_s16() which uses `&out' on a local s16 value, where that is correct.
Drop the spurious `&' so the i2c read writes into the caller's buffer.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact(default (no data)) | 55.00 |
| Exploitation signal(No additional exploitation signal) | ×1.00 |
| VPI | 55.00 |
VPI formula vpi-v1