Bug 2559667 (CVE-2026-98941) - CVE-2026-98941 kernel: kernel: Denial of Service via large folios on encrypted ext4 files
Summary: CVE-2026-98941 kernel: kernel: Denial of Service via large folios on encrypte...
Keywords:
Status: NEW
Alias: CVE-2026-98941
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-23 12:57 UTC by OSIDB Bzimport
Modified: 2026-10-27 19:53 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-10-23 12:57:31 UTC
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.


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