CVE-2024-50210

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

posix-clock: posix-clock: Fix unbalanced locking in pc_clock_settime()

If get_clock_desc() succeeds, it calls fget() for the clockids fd, and get the clk->rwsem read lock, so the error path should release the lock to make the lock balance and fput the clockids fd to make the refcount balance and release the fd related resource.

However the below commit left the error path locked behind resulting in unbalanced locking. Check timespec64_valid_strict() before get_clock_desc() to fix it, because the ts is not changed after that.

[pabeni@redhat.com: fixed commit message typo]

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/1ba33b327c3f88a7baee598979d73ab5b44d41cc
• https://git.kernel.org/stable/c/5f063bbf1ee6b01611c016b54e050a41506eb794
• https://git.kernel.org/stable/c/6e62807c7fbb3c758d233018caf94dfea9c65dbd
• https://git.kernel.org/stable/c/a8219446b95a859488feaade674d13f9efacfa32
• https://git.kernel.org/stable/c/b27330128eca25179637c1816d5a72d6cc408c66
• https://git.kernel.org/stable/c/c7fcfdba35abc9f39b83080c2bce398dad13a943
• https://git.kernel.org/stable/c/d005400262ddaf1ca1666bbcd1acf42fe81d57ce
• https://git.kernel.org/stable/c/e56e0ec1b79f5a6272c6e78b36e9d593aa0449af