smb: client: Fix use-after-free in cifs_try_adding_channels() (CVE-2026-74608) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-74608

smb: client: Fix use-after-free in cifs_try_adding_channels()

Answer in brief

CVE-2026-74608 records a Unknown severity vulnerability in smb: client: Fix use-after-free in cifs_try_adding_channels(). 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 Aug 22, 2026Updated Aug 22, 2026Source checked Aug 22, 2026First seen by HOL Aug 22, 2026Material review Aug 22, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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	>=cbc53148cc0946b72d62a3c53870cb22ce4ec284 <64d7584e62ac8cdc750455c5fdc6008fc2de4f06 \|\| >=cff97d683a083b862a8bb24309e0f4d2d928128a <c292d4686f717c03e5022fc4ae7c782f39a94915 \|\| >=6aac002bcfd554aff6d3ebb55e1660d078d70ab0 <47dfac48bce7198ad4f1a388fc8c9491f878ac3b \|\| >=6aac002bcfd554aff6d3ebb55e1660d078d70ab0 <1ffacbadc14530e55b8d86f7b917524f6a0fb891 \|\| >=6aac002bcfd554aff6d3ebb55e1660d078d70ab0 <1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805 \|\| >=6aac002bcfd554aff6d3ebb55e1660d078d70ab0 <4986410316b1ae0e63c6ce418e4eb196723626e7 \|\| 22a6c5b3425f327e7f4c3606a72277dce82c7d83 \|\| >=6.1.78 <6.1.183 \|\| >=6.6.17 <6.6.152 \|\| >=6.7.5 <6.8	64d7584e62ac8cdc750455c5fdc6008fc2de4f06, c292d4686f717c03e5022fc4ae7c782f39a94915, 47dfac48bce7198ad4f1a388fc8c9491f878ac3b, 1ffacbadc14530e55b8d86f7b917524f6a0fb891, 1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805, 4986410316b1ae0e63c6ce418e4eb196723626e7, 6.1.183, 6.6.152, 6.8
Linux/Linuxgeneric	6.8	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 64d7584e62ac8cdc750455c5fdc6008fc2de4f06 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 22, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix use-after-free in cifs_try_adding_channels() cifs_try_adding_channels() takes a temporary reference to an interface before dropping iface_lock. If cifs_ses_add_channel() fails, it drops that reference and then increments iface->weight_fulfilled. A concurrent interface list refresh can remove the list reference while channel creation is in progress. In that case, the failure-path kref_put() releases the last reference and frees iface. Updating weight_fulfilled afterward then accesses freed memory. Increment weight_fulfilled before dropping the temporary reference, keeping iface alive for the final access.

Quoted source text, attributed separately from HOL analysis.