CVE-2022-48671

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

cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all()

syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at cpuset_attach() [1], for commit 4f7e7236435ca0ab (cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock) missed that cpuset_attach() is also called from cgroup_attach_task_all(). Add cpus_read_lock() like what cgroup_procs_write_start() does.

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/07191f984842d50020789ff14c75da436a7f46a9
• https://git.kernel.org/stable/c/321488cfac7d0eb6d97de467015ff754f85813ff
• https://git.kernel.org/stable/c/43626dade36fa74d3329046f4ae2d7fdefe401c6
• https://git.kernel.org/stable/c/5db17805b6ba4c34dab303f49aea3562fc25af75
• https://git.kernel.org/stable/c/99bc25748e394d17f9e8b10cc7f273b8e64c1c7e
• https://git.kernel.org/stable/c/9f267393b036f1470fb12fb892d59e7ff8aeb58d