Commit 7272b591 authored by Lv Yunlong's avatar Lv Yunlong Committed by Greg Kroah-Hartman
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misc/libmasm/module: Fix two use after free in ibmasm_init_one 



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: default avatarLv Yunlong <lyl2019@mail.ustc.edu.cn>
Link: https://lore.kernel.org/r/20210426170620.10546-1-lyl2019@mail.ustc.edu.cn


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1553573c

drivers/misc/ibmasm/module.c

+3 −2
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ 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);
@@ -131,8 +131,9 @@ 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);