CVE-2026-99276
ksmbd: defer connection scavenging while session locks are busy
What happened?
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: defer connection scavenging while session locks are busy
The expiration worker holds conn_list_lock for reading while checking for authenticated sessions. Without this change, the check can wait for conn->session_lock or sessions_table_lock.
In destroy_previous_session(), the status updates after ksmbd_conn_wait_idle_sess() run with both session locks held for writing. Both the KSMBD_SESS_GOOD error path and the KSMBD_SESS_NEED_SETUP success path call ksmbd_all_conn_set_status(), which takes conn_list_lock for reading.
A writer queued on conn_list_lock can block these new read acquisitions. The worker then waits for a session lock held by destroy_previous_session(), which waits behind the writer. The writer cannot proceed until the worker releases conn_list_lock.
Try both session locks instead of waiting in the scavenging check. Keep the connection when either lock is busy and let the periodic worker retry later.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| LinuxLinux | affected: d7fd1f98607f2cd358e583f9548bdf0173090a86 to < 4e4e8b38994a0b0fc23f00ca6698b469a41abe70; affected: d7fd1f98607f2cd358e583f9548bdf0173090a86 to < b4bae7af1154089be87c7475218264fcbfd16d10; affected: c99ea7855124ca1428a1e59c2b4590aaef34eacf; affected: 7.2.8 to < 7.3 | See vendor advisory |
| LinuxLinux | affected: 7.3; unaffected: 0 to < 7.3; unaffected: 7.3.2 to ≤ 7.3.*; unaffected: 7.4-rc1 to ≤ * | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.