power: sequencing: fix an invalid pointer dereference in error path

We may end up calling pwrseq_target_free() on a partially initialized
target object whose unit is either NULL or an ERR_PTR(). Avoid
dereferencing invalid memory by adding an appropriate check to
pwrseq_target_free().

Fixes: 249ebf3f65f8 ("power: sequencing: implement the pwrseq core")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-pm/62a3531e-9927-40f8-b587-254a2dfa47ef@stanley.mountain/
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240712194004.241939-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/power/sequencing/core.c b/drivers/power/sequencing/core.c
index 9c32b07a55e7a2f271bd62ed73e1465f0f984802..0ffc259c6bb6c8333ba1fc5e6ab43e42ba0d3524 100644 (file)
--- a/drivers/power/sequencing/core.c
+++ b/drivers/power/sequencing/core.c
@@ -212,7 +212,8 @@ pwrseq_target_new(const struct pwrseq_target_data *data)
 
 static void pwrseq_target_free(struct pwrseq_target *target)
 {
-       pwrseq_unit_put(target->unit);
+       if (!IS_ERR_OR_NULL(target->unit))
+               pwrseq_unit_put(target->unit);
        kfree_const(target->name);
        kfree(target);
 }