CVE-2026-64016 PUBLISHED

ksmbd: fix durable reconnect error path file lifetime

Assigner: Linux
Reserved: 19.07.2026 Published: 19.07.2026 Updated: 20.07.2026

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix durable reconnect error path file lifetime

After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes the same ksmbd_file into the session volatile-id table. If smb2_open() then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp) and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp).

In this case fp and dh_info.fp are the same object. The first put drops the reconnect lookup reference, but the final durable put can run __ksmbd_close_fd(NULL, fp). Because the final close is not session-aware, it can free the file object without removing the volatile-id entry that was just published into the session table.

Use the session-aware put for the final reconnect drop when the reconnect had already succeeded and the error path is cleaning up the republished file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep using the durable-only put path.

Metrics

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

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from ce2e164c1c51c3f7813b80f8c926836e896bcbb3 to a1a39f227c80cbf369767badc32cba2b225147d1 (excl.)
  • affected from 97a0cd55283b4e63fd92804da91c8d9896adcad9 to 6cb0b9385320110fe24a5d5ac0000ade4bb3a3f3 (excl.)
  • affected from 1baff47b81f94f9231c91236aa511420d0e266b9 to 3515503322f4819277091839eed46b695096aca5 (excl.)
Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 6.18.33 to 6.18.34 (excl.)
  • affected from 7.0.10 to 7.0.11 (excl.)

References