CVE-2026-74608

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

State: Published
Severity: 9.8 Critical
Published: Aug 22, 2026
Updated: Oct 16, 2026
Reserved: Aug 15, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	cbc53148cc0946b72d62a3c53870cb22ce4ec284 to before 64d7584e62ac8cdc750455c5fdc6008fc2de4f06Affected cff97d683a083b862a8bb24309e0f4d2d928128a to before c292d4686f717c03e5022fc4ae7c782f39a94915Affected 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 47dfac48bce7198ad4f1a388fc8c9491f878ac3bAffected 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 1ffacbadc14530e55b8d86f7b917524f6a0fb891Affected 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805Affected 6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 4986410316b1ae0e63c6ce418e4eb196723626e7Affected 22a6c5b3425f327e7f4c3606a72277dce82c7d83Affected 6.1.78 to before 6.1.183Affected 6.6.17 to before 6.6.152Affected 6.7.5 to before 6.8Affected
LinuxLinux	6.8Affected before 6.8Not affected 6.1.183 through 6.1.Not affected 6.6.152 through 6.6.Not affected 6.12.104 through 6.12.Not affected 6.18.45 through 6.18.Not affected 7.1.9 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

cbc53148cc0946b72d62a3c53870cb22ce4ec284 to before 64d7584e62ac8cdc750455c5fdc6008fc2de4f06Affected
cff97d683a083b862a8bb24309e0f4d2d928128a to before c292d4686f717c03e5022fc4ae7c782f39a94915Affected
6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 47dfac48bce7198ad4f1a388fc8c9491f878ac3bAffected
6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 1ffacbadc14530e55b8d86f7b917524f6a0fb891Affected
6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 1305eadc6a7d78a8d0a52eee29ddd2d9e8a27805Affected
6aac002bcfd554aff6d3ebb55e1660d078d70ab0 to before 4986410316b1ae0e63c6ce418e4eb196723626e7Affected
22a6c5b3425f327e7f4c3606a72277dce82c7d83Affected
6.1.78 to before 6.1.183Affected
6.6.17 to before 6.6.152Affected
6.7.5 to before 6.8Affected

LinuxLinux

6.8Affected
before 6.8Not affected
6.1.183 through 6.1.*Not affected
6.6.152 through 6.6.*Not affected
6.12.104 through 6.12.*Not affected
6.18.45 through 6.18.*Not affected
7.1.9 through 7.1.*Not affected
7.2 and laterNot affected

References

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