CVE-2026-74522

ksmbd: fix use-after-free in __close_file_table_ids()

HIGH
8.8
CVSS Score
Published: August 15, 2026 at 12:27 PM UTC
Updated: August 19, 2026 at 05:21 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.8
Exploit prediction
EPSS 0.6%

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __close_file_table_ids() A ksmbd_file can remain alive after logical close while another session holds a temporary reference obtained through ksmbd_lookup_fd_inode(). ksmbd_close_fd() currently marks the file closed and drops the idr-owned reference, but leaves the pointer published in the closing session's idr until the final reference is dropped. If the foreign holder performs the final ksmbd_fd_put(), __put_fd_final() supplies the foreign session's file table to __ksmbd_close_fd(). The object is then freed without being removed from its owner's idr, and the owner session later dereferences the stale pointer during file-table teardown. Remove the volatile id from the owner's idr while ksmbd_close_fd() still holds that table's lock, and clear volatile_id before dropping the idr-owned reference. A later foreign final put then only performs physical destruction and cannot remove the object from the wrong table.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 5.15.38v ≥ 5.17.65.15.38 ≤ v < 5.165.17.6 ≤ v < 5.185.18 ≤ v < 6.1.1835.18 ≤ v < 6.12.1035.18 ≤ v < 6.18.445.18 ≤ v < 6.6.1515.18 ≤ v < 7.1.85.18 ≤ v < 7.25.15.385.17.65.188510a043d334ecdf83d4604782f288db6bf21d60aaf1d5ebb358f546414965b39da90107a7ca7ce5df30cbfd3d8a70e61ce59f63ce5ed2261799ac10
Vendor states this is fixed in 0c3918c2cee62ec6c9de8d5c73ebfe6f833961ac (fixed)
Vendor states this is fixed in 19bfd90d5aaf63217735d81964585c5306158e5f (fixed)
Vendor states this is fixed in 67aaec2a1fdce3e1dde46c45b5d1ef8cf22f65cd (fixed)
Vendor states this is fixed in 9be4a66f019ea90bd9deca70511f4f9ffebf5c6f (fixed)
Vendor states this is fixed in cffbdc86393b0235383a20c8c59bc32f16036459 (fixed)
Vendor states this is fixed in e7188199eff46a636f3436356f0aae039be6dd66 (fixed)
Affected range stops below 5.16, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 5.18 (unaffected)
Vendor states this is fixed in 6.1.183 (unaffected)
Vendor states this is fixed in 6.12.103 (unaffected)
Vendor states this is fixed in 6.18.44 (unaffected)
Vendor states this is fixed in 6.6.151 (unaffected)
Vendor states this is fixed in 7.1.8 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

8.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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