CVE-2024-38582 nilfs2: fix potential hang in nilfs_detach_log_writer()
A race condition in the nilfs2 filesystem can cause a system hang during unmount, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-38582?
CVE-2024-38582 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential hang in nilfs_detach_log_writer()
Syzbot has reported a potential hang in nilfs_detach_log_writer() called during nilfs2 unmount.
Analysis revealed that this is because nilfs_segctor_sync(), which synchronizes with the log writer thread, can be called after nilfs_segctor_destroy() terminates that thread, as shown in the call trace below:
nilfs_detach_log_writer nilfs_segctor_destroy nilfs_segctor_kill_thread --> Shut down log writer thread flush_work nilfs_iput_work_func nilfs_dispose_list iput nilfs_evict_inode nilfs_transaction_commit nilfs_construct_segment (if inode needs sync) nilfs_segctor_sync --> Attempt to synchronize with log writer thread *** DEADLOCK ***
Fix this issue by changing nilfs_segctor_sync() so that the log writer thread returns normally without synchronizing after it terminates, and by forcing tasks that are already waiting to complete once after the thread terminates.
The skipped inode metadata flushout will then be processed together in the subsequent cleanup work in nilfs_segctor_destroy().
Weakness: CWE-667
Which versions are affected by CVE-2024-38582?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-38582?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-38582 being exploited?
There is no known exploitation of CVE-2024-38582 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-38582, DEBIAN-CVE-2024-38582, GHSA-g9c8-phh2-8fqc, UBUNTU-CVE-2024-38582.