smb: client: pin DFS superblock in iterator callback (CVE-2026-97562) | HOL Guard CVE

High · CVSS 7.5CVE-2026-97562

smb: client: pin DFS superblock in iterator callback

Answer in brief

CVE-2026-97562 records a High severity (CVSS 7.5) vulnerability in smb: client: pin DFS superblock in iterator callback. 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 Sep 25, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. 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	>=bacd704a95ad0b93af995aae4a523aa046f46563 <ea43a15cea36dc5ddd832be5bddeac7dd804cbcf \|\| >=bacd704a95ad0b93af995aae4a523aa046f46563 <a6b6561522212af852c9ad8a7dca8d59ef2c7377 \|\| >=bacd704a95ad0b93af995aae4a523aa046f46563 <5b01a8c0209690db75341528ec53fd87e0ac1460 \|\| >=bacd704a95ad0b93af995aae4a523aa046f46563 <d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818	ea43a15cea36dc5ddd832be5bddeac7dd804cbcf, a6b6561522212af852c9ad8a7dca8d59ef2c7377, 5b01a8c0209690db75341528ec53fd87e0ac1460, d806d5a85dcbe2a0f181b2f0f9f61ddfbefa1818
Linux/Linuxgeneric	5.7	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to ea43a15cea36dc5ddd832be5bddeac7dd804cbcf if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: smb: client: pin DFS superblock in iterator callback tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super() takes its active reference only after iterate_supers_type() has dropped s_umount and its passive reference. Concurrent DFS automount expiry can therefore free the superblock before cifs_sb_active() uses it. A deterministic KASAN test reproduces the race as: BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80 The same test passes with this change applied. Take the active reference in the callback while iterate_supers_type() still holds s_umount shared. cifs_put_tcp_super() remains the matching release.

Quoted source text, attributed separately from HOL analysis.