Use After Free Affecting kernel-rt-debug package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug package and not the kernel-rt-debug package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

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.

• https://access.redhat.com/security/cve/CVE-2021-47334
• https://git.kernel.org/stable/c/1512e7dc5eb08b7d92a12e2bfcd9cb8c4a1ec069
• https://git.kernel.org/stable/c/29ba8e2ba89ee2862a26d91204dd5fe77ceee25a
• https://git.kernel.org/stable/c/38660031e80eaa6cc9370b031c180612f414b00d
• https://git.kernel.org/stable/c/481a76d4749ee3a27f902ba213fdcbb4bb39720e
• https://git.kernel.org/stable/c/5b06ca113bf197aab2ab61288f42506e0049fbab
• https://git.kernel.org/stable/c/7272b591c4cb9327c43443f67b8fbae7657dd9ae
• https://git.kernel.org/stable/c/a7268e8a227d5a4f0bd1584f556246b0224ab274
• https://git.kernel.org/stable/c/b9c87ce3bc6331f82811a8cf8e930423c22523a3
• https://git.kernel.org/stable/c/ef1067d2baa847d53c9988510d99fb494de4d12c