CVE-2026-68459 f2fs: fix potential deadlock in gc_merge path of f2fs_balance_fs()
A race condition in the Linux kernel f2fs filesystem can cause a deadlock when the gc_merge mount option is enabled, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68459?
CVE-2026-68459 is a vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix potential deadlock in gc_merge path of f2fs_balance_fs()
When we mount device w/ gc_merge mount option, we may suffer below potential deadlock:
Kworker GC trehad Truncator - f2fs_write_cache_pages - f2fs_write_single_data_page - f2fs_do_write_data_page - folio_start_writeback --- set writeback flag on folio - f2fs_outplace_write_data : cached folio in internal bio cache - f2fs_balance_fs - wake_up(gc_thread) : wake up gc thread to run foreground GC - finish_wait(fggc_wq) : wait on the waitqueue --- wait on GC thread to finish the work - truncate_inode_pages_range - __filemap_get_folio(, FGP_LOCK) --- lock folio - truncate_inode_partial_folio - folio_wait_writeback --- wait on writeback being cleared - do_garbage_collect - move_data_page - f2fs_get_lock_data_folio - lock on folio --- blocked on folio's lock
In order to avoid such deadlock, let's call below functions to commit cached bios in GC_MERGE path of f2fs_balance_fs() as the same as we did in NOGC_MERGE path. - f2fs_submit_merged_write(sbi, DATA); - f2fs_submit_all_merged_ipu_writes(sbi);
Which versions are affected by CVE-2026-68459?
How do I fix CVE-2026-68459?
Apply the vendor's patch.
Is CVE-2026-68459 being exploited?
There is no known exploitation of CVE-2026-68459 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68459, DEBIAN-CVE-2026-68459, GHSA-phqv-2q9m-94vv, UBUNTU-CVE-2026-68459.