CVE-2026-68459

About vulnerability

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);

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 4.19.0 (+17 more)

Live-patch status from KernelCare for each operating system.