From: Brad Spengler <spender@xxxxxxxxxxxxxx>
Grsecurity uses memory poisoning and detected a use after free in
rmi_unregister_function(). A fix for this was merged into the
grsecurity patchset. I detected the user after free later using static
analysis and sent a partial fix as commit eb988e46da2e ("Input:
synaptics-rmi4 - fix use after free in rmi_unregister_function()").
However, my patch meant that the grsecurity patchset didn't apply cleanly
and forced everyone to re-visit this issue.
The bug is that we must not call device_del() until after calling
irq_dispose_mapping().
Fixes: 24d28e4f1271 ("Input: synaptics-rmi4 - convert irq distribution to irq_domain")
Reported-by: Torsten Hilbrich <torsten.hilbrich@xxxxxxxxxxx>
Closes: https://lore.kernel.org/all/1932038e-2776-04ac-5fcd-b15bb3cd088d@xxxxxxxxxxx/
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215604
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/input/rmi4/rmi_bus.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/input/rmi4/rmi_bus.c b/drivers/input/rmi4/rmi_bus.c
index 1b45b1d3077d..02acc81b9d3e 100644
--- a/drivers/input/rmi4/rmi_bus.c
+++ b/drivers/input/rmi4/rmi_bus.c
@@ -275,12 +275,11 @@ void rmi_unregister_function(struct rmi_function *fn)
rmi_dbg(RMI_DEBUG_CORE, &fn->dev, "Unregistering F%02X.\n",
fn->fd.function_number);
- device_del(&fn->dev);
- of_node_put(fn->dev.of_node);
-
for (i = 0; i < fn->num_of_irqs; i++)
irq_dispose_mapping(fn->irq[i]);
+ device_del(&fn->dev);
+ of_node_put(fn->dev.of_node);
put_device(&fn->dev);
}
--
2.43.0
