Skip to content
Fencer Vulns
medium 5.5

CVE-2025-22127 json

f2fs: fix potential deadloop in prepare_compress_overwrite()

published 2025-04-16 18 mo ago modified 2026-10-30 10 d ago also EUVD-2025-11167

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

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

f2fs: fix potential deadloop in prepare_compress_overwrite()

Jan Prusakowski reported a kernel hang issue as below:

When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I encountered a problem in generic/475 test where fsstress process gets blocked in __f2fs_write_data_pages() and the test hangs. The options I used are:

MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc

INFO: task kworker/u8:0:11 blocked for more than 122 seconds. Not tainted 6.14.0-rc3-xfstests-lockdep #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: writeback wb_workfn (flush-253:0) Call Trace: <TASK> __schedule+0x309/0x8e0 schedule+0x3a/0x100 schedule_preempt_disabled+0x15/0x30 __mutex_lock+0x59a/0xdb0 __f2fs_write_data_pages+0x3ac/0x400 do_writepages+0xe8/0x290 __writeback_single_inode+0x5c/0x360 writeback_sb_inodes+0x22f/0x570 wb_writeback+0xb0/0x410 wb_do_writeback+0x47/0x2f0 wb_workfn+0x5a/0x1c0 process_one_work+0x223/0x5b0 worker_thread+0x1d5/0x3c0 kthread+0xfd/0x230 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 </TASK>

The root cause is: once generic/475 starts toload error table to dm device, f2fs_prepare_compress_overwrite() will loop reading compressed cluster pages due to IO error, meanwhile it has held .writepages lock, it can block all other writeback tasks.

Let's fix this issue w/ below changes: - add f2fs_handle_page_eio() in prepare_compress_overwrite() to detect IO error. - detect cp_error earler in f2fs_read_multi_pages().

Patch / fix

  • Linux Linux 6.1.191, 6.6.160, 6.12.109, 6.14.2, 6.15
  • linux Debian 13 6.12.111-1
  • linux Debian 14 6.16.3-1
  • linux-6.12 Debian 12 6.12.111-1~deb12u1

debian advisories DEBIAN-CVE-2025-22127

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-22127 updated

kernel: f2fs: fix potential deadloop in prepare_compress_overwrite()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.