CVE-2026-63934 iio: gyro: itg3200: fix i2c read into the wrong stack location
A local attacker can read uninitialized kernel stack memory via the ITG3200 gyroscope driver, potentially leaking sensitive information.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63934?
CVE-2026-63934 is a vulnerability in Linux, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-63934?
How do I fix CVE-2026-63934?
Apply the vendor's patch.
Is CVE-2026-63934 being exploited?
There is no known exploitation of CVE-2026-63934 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63934, DEBIAN-CVE-2026-63934, GHSA-xvpq-5jw7-83gf, ROOT-OS-UBUNTU-2204-CVE-2026-63934, UBUNTU-CVE-2026-63934.