In the Linux kernel, the following vulnerability has been resolved:
jbd2: avoid bug_on in jbd2_journal_get_create_access() when file system corrupted
There's issue when file system corrupted:
------------[ cut here ]------------
kernel BUG at fs/jbd2/transaction.c:1289!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 5 UID: 0 PID: 2031 Comm: mkdir Not tainted 6.18.0-rc1-next
RIP: 0010:jbd2_journal_get_create_access+0x3b6/0x4d0
RSP: 0018:ffff888117aafa30 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff88811a86b000 RCX: ffffffff89a63534
RDX: 1ffff110200ec602 RSI: 0000000000000004 RDI: ffff888100763010
RBP: ffff888100763000 R08: 0000000000000001 R09: ffff888100763028
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88812c432000 R14: ffff88812c608000 R15: ffff888120bfc000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91d6970c99 CR3: 00000001159c4000 CR4: 00000000000006f0
Call Trace:
__ext4_journal_get_create_access+0x42/0x170
ext4_getblk+0x319/0x6f0
ext4_bread+0x11/0x100
ext4_append+0x1e6/0x4a0
ext4_init_new_dir+0x145/0x1d0
ext4_mkdir+0x326/0x920
vfs_mkdir+0x45c/0x740
do_mkdirat+0x234/0x2f0
__x64_sys_mkdir+0xd6/0x120
do_syscall_64+0x5f/0xfa0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The above issue occurs with us in errors=continue mode when accompanied by
storage failures. There have been many inconsistencies in the file system
data.
In the case of file system data inconsistency, for example, if the block
bitmap of a referenced block is not set, it can lead to the situation where
a block being committed is allocated and used again. As a result, the
following condition will not be satisfied then trigger BUG_ON. Of course,
it is entirely possible to construct a problematic image that can trigger
this BUG_ON through specific operations. In fact, I have constructed such
an image and easily reproduced this issue.
Therefore, J_ASSERT() holds true only under ideal conditions, but it may
not necessarily be satisfied in exceptional scenarios. Using J_ASSERT()
directly in abnormal situations would cause the system to crash, which is
clearly not what we want. So here we directly trigger a JBD abort instead
of immediately invoking BUG_ON.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-05). 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