misc/libmasm/module: Fix two use after free in ibmasm_init_one

[ Upstream commit 7272b591c4cb9327c43443f67b8fbae7657dd9ae ]

In ibmasm_init_one, it calls ibmasm_init_remote_input_dev().
Inside ibmasm_init_remote_input_dev, mouse_dev and keybd_dev are
allocated by input_allocate_device(), and assigned to
sp->remote.mouse_dev and sp->remote.keybd_dev respectively.

In the err_free_devices error branch of ibmasm_init_one,
mouse_dev and keybd_dev are freed by input_free_device(), and return
error. Then the execution runs into error_send_message error branch
of ibmasm_init_one, where ibmasm_free_remote_input_dev(sp) is called
to unregister the freed sp->remote.mouse_dev and sp->remote.keybd_dev.

My patch add a "error_init_remote" label to handle the error of
ibmasm_init_remote_input_dev(), to avoid the uaf bugs.

Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Link: https://lore.kernel.org/r/20210426170620.10546-1-lyl2019@mail.ustc.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/misc/ibmasm/module.c b/drivers/misc/ibmasm/module.c
index e914b8c80943316a270ac3ba9e64bcc1addbc979..9f8344169845ced9421fec3f64e21aaccee454ac 100644 (file)
--- a/drivers/misc/ibmasm/module.c
+++ b/drivers/misc/ibmasm/module.c
@@ -125,7 +125,7 @@ static int ibmasm_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
        result = ibmasm_init_remote_input_dev(sp);
        if (result) {
                dev_err(sp->dev, "Failed to initialize remote queue\n");
-               goto error_send_message;
+               goto error_init_remote;
        }
 
        result = ibmasm_send_driver_vpd(sp);
@@ -145,8 +145,9 @@ static int ibmasm_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
        return 0;
 
 error_send_message:
-       disable_sp_interrupts(sp->base_address);
        ibmasm_free_remote_input_dev(sp);
+error_init_remote:
+       disable_sp_interrupts(sp->base_address);
        free_irq(sp->irq, (void *)sp);
 error_request_irq:
        iounmap(sp->base_address);