PT-2026-36348 · Linux · Linux Kernel
Published
2026-05-01
·
Updated
2026-05-23
·
CVE-2026-31718
CVSS v3.1
9.8
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
A use-after-free issue exists in the ksmbd module of the Linux kernel. When a durable file handle persists after a session disconnect (TCP close without SMB2 LOGOFF), the
session fd check() function sets fp->conn to NULL but fails to clean up byte-range locks on fp->lock list. Subsequently, when the durable scavenger thread times out and invokes the ksmbd close fd() function, it attempts to acquire a spin lock using fp->conn->llist lock. Since fp->conn is NULL and the original connection object was already freed by ksmbd tcp disconnect(), a slab use-after-free occurs. This is caused by asymmetric cleanup where lock entries (smb lock->clist) remain dangling on the freed conn->lock list while fp->conn is nulled.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
RCE
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Linux Kernel