In the Linux kernel, the following vulnerability has been resolved:
pinctrl: devicetree: dont free uninitialized dev_name on error path
dt_remember_or_free_map() duplicates dev_name for each map entry. If kstrdup_const() fails, dt_free_map() frees dev_name in all num_maps entries, including entries that have not been initialized.
Some pinctrl drivers, including pinctrl-imx, allocate the map with kmalloc() and leave dev_name for the core to initialize. The untouched entries therefore contain uninitialized data which is passed to kfree_const().
Reproduced on qemus mcimx6ul-evk (pinctrl-imx) with failslab injection while binding the pinctrl-consuming device, under KASAN:
BUG: KASAN: double-free in dt_free_map+0x34/0xa4 Free of addr c425a900 by task init/1 kfree from dt_free_map+0x34/0xa4 dt_free_map from dt_remember_or_free_map+0x184/0x198 dt_remember_or_free_map from pinctrl_dt_to_map+0x33c/0x4c8 pinctrl_dt_to_map from create_pinctrl+0x9c/0x5c0
Initialize all dev_name fields to NULL before duplicating the device name, making the full-map cleanup safe after a partial failure.
References
- https://git.kernel.org/stable/c/015b5bcbcb622b32317642be91a7f79aa5413649
- https://git.kernel.org/stable/c/321fe3584a8298386938130d138191aa35040b75
- https://git.kernel.org/stable/c/929f6396baade89999ec8a1281232c101cbc727d
- https://git.kernel.org/stable/c/9d00a5ac7cd3d32ae61140f4b8a62f136de84e7d
- https://git.kernel.org/stable/c/ad0ad3c228b6f76fde10f32047e0ec5fbc109dc8