vulnerability

Ubuntu: (CVE-2021-47334): linux vulnerability

Severity
7
CVSS
(AV:L/AC:L/Au:S/C:C/I:C/A:C)
Published
May 21, 2024
Added
Nov 19, 2024
Modified
Sep 5, 2025

Description

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.

Solutions

ubuntu-upgrade-linuxubuntu-upgrade-linux-awsubuntu-upgrade-linux-aws-5-4ubuntu-upgrade-linux-aws-fipsubuntu-upgrade-linux-aws-hweubuntu-upgrade-linux-azureubuntu-upgrade-linux-azure-4-15ubuntu-upgrade-linux-azure-5-4ubuntu-upgrade-linux-azure-fipsubuntu-upgrade-linux-bluefieldubuntu-upgrade-linux-fipsubuntu-upgrade-linux-gcpubuntu-upgrade-linux-gcp-4-15ubuntu-upgrade-linux-gcp-5-4ubuntu-upgrade-linux-gcp-fipsubuntu-upgrade-linux-gkeopubuntu-upgrade-linux-hweubuntu-upgrade-linux-hwe-5-4ubuntu-upgrade-linux-ibmubuntu-upgrade-linux-kvmubuntu-upgrade-linux-oracleubuntu-upgrade-linux-oracle-5-4ubuntu-upgrade-linux-raspiubuntu-upgrade-linux-raspi-5-4

References

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