In the Linux kernel, the following vulnerability has been resolved: isofs: handle set_blocksize failures isofs uses buffer_heads, which don't handle… (CVE-2026-98879)
Description
A vulnerability in the Linux kernel's isofs filesystem code was resolved. The issue involved improper handling of set_blocksize failures because isofs uses buffer_heads, which do not handle block sizes larger than PAGE_SIZE correctly. This could cause a kernel BUG_ON failure during mounting due to an offset exceeding the folio size.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's isofs filesystem used buffer_heads that do not properly support block sizes greater than PAGE_SIZE. This flaw could cause a BUG_ON condition in folio_set_bh during the first __bread_gfp call when mounting an isofs filesystem. The vulnerability was addressed by improving handling of set_blocksize failures to prevent this kernel crash.
Potential Impact
This vulnerability could lead to a kernel crash (BUG_ON) when mounting an isofs filesystem with block sizes larger than PAGE_SIZE, potentially causing denial of service on affected systems.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to handle set_blocksize failures properly in the isofs filesystem code. Users should apply the official kernel update that includes this fix. Patch status is not explicitly confirmed here; check the vendor or Linux kernel advisory for the exact fixed versions and update accordingly.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-q9wc-mgjh-78f8
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-98879"]
Threat ID: 6adbaad9d73cc49347b2072c
Added to database: 10/23/2026, 18:43:37 UTC
Last enriched: 10/23/2026, 19:06:06 UTC
Last updated: 10/23/2026, 19:45:16 UTC
Views: 6
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