CVE-2021-47334

HIGH
Published May 21, 2024 Modified Dec 26, 2024 CWE-416

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.

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CVSS v3.1 Score

7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

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 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

Frequently Asked Questions

What is 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 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. It has a CVSS v3.1 base score of 7.8 (HIGH).
How severe is CVE-2021-47334? +
CVE-2021-47334 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2021-47334? +
CVE-2021-47334 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47334? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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