CVE-2026-23233

highpriority · track · 31EPSS 0.002 · 6 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.17% (6th) EPSS
CVSS 7.8 · high
Is it mine?
46 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid mapping wrong physical block for swapfile Xiaolong Guo reported a f2fs bug in bugzilla [1] [1] https://bugzilla.kernel.org/show_bug.cgi?id=220951 Quoted: "When using stress-ng's swap stress test on F2FS filesystem with kernel 6.6+, the system experiences data corruption leading to either: 1 dm-verity corruption errors and device reboot 2 F2FS node corruption errors and boot hangs The issue occurs specifically when: 1 Using F2FS filesystem (ext4 is unaffected) 2 Swapfile size is less than F2FS section size (2MB) 3 Swapfile has fragmented physical layout (multiple non-contiguous extents) 4 Kernel version is 6.6+ (6.1 is unaffected) The root cause is in check_swap_activate() function in fs/f2fs/data.c. When the first extent of a small swapfile (< 2MB) is not aligned to section boundaries, the function incorrectly treats it as the last extent, failing to map subsequent extents. This results in incorrect swap_extent creation where only the first extent is mapped, causing subsequent swap writes to overwrite wrong physical locations (other files' data). Steps to Reproduce 1 Setup a device with F2FS-formatted userdata partition 2 Compile stress-ng from https://github.com/ColinIanKing/stress-ng 3 Run swap stress test: (Android devices) adb shell "cd /data/stressng; ./stress-ng-64 --metrics-brief --timeout 60 --swap 0" Log: 1 Ftrace shows in kernel 6.6, only first extent is mapped during second f2fs_map_blocks call in check_swap_activate(): stress-ng-swap-8990: f2fs_map_blocks: ino=11002, file offset=0, start blkaddr=0x43143, len=0x1 (Only 4KB mapped, not the full swapfile) 2 in kernel 6.1, both extents are correctly mapped: stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=0, start blkaddr=0x13cd4, len=0x1 stress-ng-swap-5966: f2fs_map_blocks: ino=28011, file offset=1, start blkaddr=0x60c84b, len=0xff The problematic code is in check_swap_activate(): if ((pblock - SM_I(sbi)->main_blkaddr) % blks_per_sec || nr_pblocks % blks_per_sec || !f2fs_valid_pinned_area(sbi, pblock)) { bool last_extent = false; not_aligned++; nr_pblocks = roundup(nr_pblocks, blks_per_sec); if (cur_lblock + nr_pblocks > sis->max) nr_pblocks -= blks_per_sec; /* this extent is last one */ if (!nr_pblocks) { nr_pblocks = last_lblock - cur_lblock; last_extent = true; } ret = f2fs_migrate_blocks(inode, cur_lblock, nr_pblocks); if (ret) { if (ret == -ENOENT) ret = -EINVAL; goto out; } if (!last_extent) goto retry; } When the first extent is unaligned and roundup(nr_pblocks, blks_per_sec) exceeds sis->max, we subtract blks_per_sec resulting in nr_pblocks = 0. The code then incorrectly assumes this is the last extent, sets nr_pblocks = last_lblock - cur_lblock (entire swapfile), and performs migration. After migration, it doesn't retry mapping, so subsequent extents are never processed. " In order to fix this issue, we need to lookup block mapping info after we migrate all blocks in the tail of swapfile.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • Fixedkernel-devel-0:6.19.8-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-devel-0:6.19.8-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-devel-0:6.19.8-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-devel-0:6.19.8-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-macros-0:6.19.8-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-macros-0:6.19.8-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-macros-0:6.19.8-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-macros-0:6.19.8-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-0:6.19.8-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-0:6.19.8-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-0:6.19.8-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-0:6.19.8-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-vanilla-0:6.19.8-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-vanilla-0:6.19.8-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-vanilla-0:6.19.8-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

  • Fixedkernel-source-vanilla-0:6.19.8-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf

    To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".

02

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Hsecondary · SUSE Product Security
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (46)

Products and version ranges known to be affected.

showing 20 of 46
05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-0614Linux Kernel: Mehrere SchwachstellenDeutsch2026-03-04csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, die möglicherweise zu einer Denial-of-Service-Bedingung führen oder eine Speicherbeschädigung verursachen können.

  • openSUSE-SU-2026:10387-1kernel-devel-6.19.8-1.1 on GA media2026-03-18csaf · suse_csafDE

    kernel-devel-6.19.8-1.1 on GA media

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

09

references (17)

External citations — patches, advisories, analysis.

scry

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