f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode (CVE-2026-63816) | HOL Guard CVE

High · CVSS 7.8CVE-2026-63816

f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode

Answer in brief

CVE-2026-63816 records a High severity (CVSS 7.8) vulnerability in f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 19, 2026Updated Aug 17, 2026Source checked Sep 19, 2026First seen by HOL Aug 5, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=3db1de0e582c358dd013f3703cd55b5fe4076436 <7d3ae21783e5914c1761ac7d63f882d3d70800e9 \|\| >=3db1de0e582c358dd013f3703cd55b5fe4076436 <56038756aae68312df00d4aa1d97e51ef3aca725 \|\| >=3db1de0e582c358dd013f3703cd55b5fe4076436 <a499f77c06050a28c897bdbd86cd2f0721ae0743 \|\| >=3db1de0e582c358dd013f3703cd55b5fe4076436 <a805fec35c201c59643ddcde713bce4051c8ee27 \|\| >=3db1de0e582c358dd013f3703cd55b5fe4076436 <e0288584baa5dc41df4a829a023c4c1b33fe53d7 \|\| 6db52f1944417c2601182a591a704e2f119c5215 \|\| >=5.18.18 <5.19	7d3ae21783e5914c1761ac7d63f882d3d70800e9, 56038756aae68312df00d4aa1d97e51ef3aca725, a499f77c06050a28c897bdbd86cd2f0721ae0743, a805fec35c201c59643ddcde713bce4051c8ee27, e0288584baa5dc41df4a829a023c4c1b33fe53d7, 5.19
Linux/Linuxgeneric	5.19	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 7d3ae21783e5914c1761ac7d63f882d3d70800e9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode - ioctl(F2FS_IOC_GARBAGE_COLLECT_RANGE) - shrink - f2fs_gc - gc_data_segment - ra_data_block(cow_inode) - mapping = F2FS_I(inode)->atomic_inode->i_mapping : f2fs_is_cow_file(cow_inode) is true - f2fs_evict_inode(atomic_inode) - clear_inode_flag(fi->cow_inode, FI_COW_FILE) - F2FS_I(fi->cow_inode)->atomic_inode = NULL ... - truncate_inode_pages_final(atomic_inode) - f2fs_grab_cache_folio(mapping) : create folio in atomic_inode->mapping - clear_inode(atomic_inode) - BUG_ON(atomic_inode->i_data.nrpages) We need to add a reference on fi->atomic_inode before using its mapping field during garbage collection, otherwise, it will cause UAF issue.

Quoted source text, attributed separately from HOL analysis.