In the Linux kernel, the following vulnerability has been resolved:
ext4: fix access to uninitialised lock in fc replay path
The following kernel trace can be triggered with fstest generic/629 when
executed against a filesystem with fast-commit feature enabled:
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 866 Comm: mount Not tainted 6.10.0+ #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x66/0x90
register_lock_class+0x759/0x7d0
__lock_acquire+0x85/0x2630
? __find_get_block+0xb4/0x380
lock_acquire+0xd1/0x2d0
? __ext4_journal_get_write_access+0xd5/0x160
_raw_spin_lock+0x33/0x40
? __ext4_journal_get_write_access+0xd5/0x160
__ext4_journal_get_write_access+0xd5/0x160
ext4_reserve_inode_write+0x61/0xb0
__ext4_mark_inode_dirty+0x79/0x270
? ext4_ext_replay_set_iblocks+0x2f8/0x450
ext4_ext_replay_set_iblocks+0x330/0x450
ext4_fc_replay+0x14c8/0x1540
? jread+0x88/0x2e0
? rcu_is_watching+0x11/0x40
do_one_pass+0x447/0xd00
jbd2_journal_recover+0x139/0x1b0
jbd2_journal_load+0x96/0x390
ext4_load_and_init_journal+0x253/0xd40
ext4_fill_super+0x2cc6/0x3180
...
In the replay path there's an attempt to lock sbi->s_bdev_wb_lock in
function ext4_check_bdev_write_error(). Unfortunately, at this point this
spinlock has not been initialized yet. Moving it's initialization to an
earlier point in __ext4_fill_super() fixes this splat.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it