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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: 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>

authored by

Lv Yunlong and committed by
Greg Kroah-Hartman
7272b591 1553573c

+3 -2
+3 -2
drivers/misc/ibmasm/module.c
··· 111 111 result = ibmasm_init_remote_input_dev(sp); 112 112 if (result) { 113 113 dev_err(sp->dev, "Failed to initialize remote queue\n"); 114 - goto error_send_message; 114 + goto error_init_remote; 115 115 } 116 116 117 117 result = ibmasm_send_driver_vpd(sp); ··· 131 131 return 0; 132 132 133 133 error_send_message: 134 - disable_sp_interrupts(sp->base_address); 135 134 ibmasm_free_remote_input_dev(sp); 135 + error_init_remote: 136 + disable_sp_interrupts(sp->base_address); 136 137 free_irq(sp->irq, (void *)sp); 137 138 error_request_irq: 138 139 iounmap(sp->base_address);