Null pointer dereference in Linux kernel ext4 on encrypted inodes
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The Linux kernel ext4 filesystem from 6.19 before 7.2.10 is affected. Enabling the encrypt feature on a mounted filesystem bypasses a mount-time check that disables large folios, so writing encrypted data causes a NULL pointer dereference and kernel crash.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: ext4: don't enable large folios on encrypted inodes Commit 709f0f1f1bf5 ("ext4: add checks for large folio incompatibilities when BS > PS") disables large folios at mount time if the "encrypt" feature is set. However, enabling that feature on a mounted filesystem circumvents that check, and writing encrypted data results in a crash: BUG: kernel NULL pointer dereference, address: 0000000000000028 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work RIP: 0010:ext4_finish_bio+0xf7/0x3e0 Call Trace: ext4_release_io_end+0x51/0x110 ext4_end_io_end+0x4c/0xe0 ext4_end_io_rsv_work+0xb3/0x100 Fix this by disabling large folios on encrypted inodes, as is already done for inodes that use data journaling. This affects all kernels between v6.19 and v7.2, but it is not needed in v7.3, where the code was significantly refactored.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to 7.2.10 or later. Red Hat Enterprise Linux 6 is affected and Red Hat lists no fix planned for it.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 7.2.10
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-23 Threatist record created from CVE-2026-98941
- 2026-10-23 Alias added: GHSA-jjvw-qjpr-6rpv
- 2026-10-24 CVSS score added · CNA
- 2026-10-24 Priority changed: LOW → MEDIUM
- 2026-10-24 Priority changed: MEDIUM → LOW
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
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Sources
- CVE-2026-98941 · CVE Program
- CVE-2026-98941 · NVD
- FIRST EPSS
- GHSA-jjvw-qjpr-6rpv · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98941 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences