PSE PI regulators are devm-registered inside pse_controller_register(), which runs before devres_add() arms the controller's own release in devm_pse_controller_register(). On driver detach, devres unwinds in LIFO order, so pse_controller_unregister() runs first and frees pcdev->pi via pse_release_pis(); the regulators are torn down afterwards. When regulator_unregister() flushes a pending disable, the regulator core invokes pse_pi_disable(), which dereferences pcdev->pi[id] (directly and via _pse_pi_disable() -> pse_pi_deallocate_pw_budget()). At that point the PI array is already freed, so this is a use-after-free. pse_release_pis() now clears pcdev->pi after freeing it, and pse_pi_disable() bails out under the lock when pcdev->pi is NULL, so a late disable from the regulator core is a no-op once the controller has been unregistered. Fixes: ffef61d6d273 ("net: pse-pd: Add support for budget evaluation strategies") Signed-off-by: Carlo Szelinsky --- drivers/net/pse-pd/pse_core.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/net/pse-pd/pse_core.c b/drivers/net/pse-pd/pse_core.c index 17f45e4b672b..9ae0df3cb5cf 100644 --- a/drivers/net/pse-pd/pse_core.c +++ b/drivers/net/pse-pd/pse_core.c @@ -145,6 +145,7 @@ static void pse_release_pis(struct pse_controller_dev *pcdev) of_node_put(pcdev->pi[i].np); } kfree(pcdev->pi); + pcdev->pi = NULL; } /** @@ -702,15 +703,21 @@ static int pse_pi_enable(struct regulator_dev *rdev) static int pse_pi_disable(struct regulator_dev *rdev) { struct pse_controller_dev *pcdev = rdev_get_drvdata(rdev); - struct pse_pi *pi; int id, ret; id = rdev_get_id(rdev); - pi = &pcdev->pi[id]; mutex_lock(&pcdev->lock); + /* The controller may already be unregistered (pcdev->pi freed) by the + * time the regulator core flushes a deferred disable during + * regulator_unregister(). Bail out to avoid touching freed PI data. + */ + if (!pcdev->pi) { + mutex_unlock(&pcdev->lock); + return 0; + } ret = _pse_pi_disable(pcdev, id); if (!ret) - pi->admin_state_enabled = 0; + pcdev->pi[id].admin_state_enabled = 0; mutex_unlock(&pcdev->lock); return 0; -- 2.43.0