CVE-2026-97489: bfs: handle set_blocksize failures
Published Sep 24, 2026
·Updated
In the Linux kernel, the following vulnerability has been resolved:
bfs: handle setblocksize failures
bfs uses bufferheads, which don't handle block size > PAGESIZE well. Without this, mounting will hit the
BUGON(offset >= foliosize(folio));
in foliosetbh on the first breadgfp call.
Affected Software
1 affected component
Linux Linux kernel
Event History
Sep 24, 2026
CVE Published
via MITRE·04:04 PM
Data Sourced
via MITRE·04:04 PM
Description
Data Sourced
via NVD·05:17 PM
Description
Frequently Asked Questions
1
What condition triggers the failure?
The failure occurs when BFS is mounted with a block size larger than PAGE_SIZE. BFS uses buffer_heads, which do not handle that block-size condition correctly.
2
What is the observed impact when the vulnerable code is reached?
The mount path can hit a BUG_ON in folio_set_bh during the first __bread_gfp call, specifically the offset >= folio_size(folio) assertion.
3
What should be done to remediate the issue?
Apply a Linux kernel update containing the BFS fix that handles set_blocksize failures. The provided stable kernel references identify commits carrying the correction.