Vulnerabilities > CVE-2022-48931 - Race Condition vulnerability in Linux Kernel
Summary
In the Linux kernel, the following vulnerability has been resolved: configfs: fix a race in configfs_{,un}register_subsystem() When configfs_register_subsystem() or configfs_unregister_subsystem() is executing link_group() or unlink_group(), it is possible that two processes add or delete list concurrently. Some unfortunate interleavings of them can cause kernel panic. One of cases is: A --> B --> C --> D A <-- B <-- C <-- D delete list_head *B | delete list_head *C --------------------------------|----------------------------------- configfs_unregister_subsystem | configfs_unregister_subsystem unlink_group | unlink_group unlink_obj | unlink_obj list_del_init | list_del_init __list_del_entry | __list_del_entry __list_del | __list_del // next == C | next->prev = prev | | next->prev = prev prev->next = next | | // prev == B | prev->next = next Fix this by adding mutex when calling link_group() or unlink_group(), but parent configfs_subsystem is NULL when config_item is root. So I create a mutex configfs_subsystem_mutex.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.
References
- https://git.kernel.org/stable/c/40805099af11f68c5ca7dbcfacf455da8f99f622
- https://git.kernel.org/stable/c/d1654de19d42f513b6cfe955cc77e7f427e05a77
- https://git.kernel.org/stable/c/a37024f7757c25550accdebf49e497ad6ae239fe
- https://git.kernel.org/stable/c/b7e2b91fcb5c78c414e33dc8d50642e307ca0c5a
- https://git.kernel.org/stable/c/a7ab53d3c27dfe83bb594456b9f38a37796ec39b
- https://git.kernel.org/stable/c/e7a66dd2687758718eddd79b542a95cf3aa488cc
- https://git.kernel.org/stable/c/3aadfd46858b1f64d4d6a0654b863e21aabff975
- https://git.kernel.org/stable/c/84ec758fb2daa236026506868c8796b0500c047d