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CVE-2021-47334

In the Linux kernel, the following vulnerability has been resolved: misc/libmasm/module: Fix two use after free in ibmasm_init_one In ibmasm_init_one, it calls…

Impact

In the Linux kernel, the following vulnerability has been resolved: 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.

Affected products

VendorProductAffected versions
LinuxLinux Kernel
before 4.4.276
from 4.5 before 4.9.276
from 4.10 before 4.14.240
from 4.15 before 4.19.198
from 4.20 before 5.4.134
from 5.5 before 5.10.52

Weakness classification

CWE-416

References