Vulnerability in Linux kernel (CVE-2026-92502)
Summary
Vulnerability in Linux kernel (CVE-2026-92502). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
ext4: clear stale xarray tags on folios skipped during writeback
In data=journal mode, the writeback thread can hit the
WARN_ON_ONCE(sb_rdonly(sb)) in ext4_journal_check_start() while the
superblock is being remounted read-only during reboot:
Workqueue: writeback wb_workfn (flush-253:0)
RIP: 0010:ext4_journal_check_start+0x8b/0xd0
Call Trace:
__ext4_journal_start_sb+0x3c/0x1e0
mpage_prepare_extent_to_map+0x4af/0x580
ext4_do_writepages+0x3c0/0x1080
ext4_writepages+0xc8/0x1a0
do_writepages+0xc4/0x180
__writeback_single_inode+0x45/0x2f0
writeback_sb_inodes+0x26b/0x5d0
__writeback_inodes_wb+0x54/0x100
wb_writeback+0x1ac/0x320
wb_workfn+0x394/0x470
And followed by the warning:
EXT4-fs warning (device vda1): ext4_evict_inode:195: inode #6263:
comm (sd-umount): data will be lost
This issue is not reproduced every time, but frequently.
The reproduction step is to create a VM with 8 CPUs, 16G memory and
setup data=journal:
sudo tune2fs -o journal_data /dev/vda1
Run fio:
rm -f fiotest
fio --name=fiotest --rw=randwrite --bs=4k --runtime=6 --ioengine=libaio
--iodepth=256 --numjobs=8 --filename=fiotest --filesize=30G
--group_reporting
Reboot the VM, and check the console output from:
virsh console testvm
But there is no dirty inode, folio_clear_dirty_for_io clears PG_dirty
but leaves tags PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE set which
are only cleared by __folio_start_writeback.
In data=…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-92502 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-92502" on the vendor's site.
CVE-2026-92502 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com