CVE-2026-99277
ksmbd: hold a connection reference for each session channel
What happened?
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: hold a connection reference for each session channel
ksmbd_session_unregister() removes a session from the global and per- connection tables before dropping the table reference. A concurrent reference holder can keep the session and its channel list alive after those removals.
Connection cleanup can no longer find the unpublished session to remove its channels. Since a channel only stores a raw conn pointer, the connection can be freed while another session reference holder is still accessing it, for example during SMB3.1.1 binding or a procfs read.
Take a connection reference when registering a channel and release it on insertion failure, channel removal, or final session destruction. Keep the channels and signing keys until the session is destroyed so a response can still be signed after the session has been unregistered.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| LinuxLinux | affected: d7fd1f98607f2cd358e583f9548bdf0173090a86 to < 4b333aed69cfc2c8687b86b6a4364a0dffc16dd8; affected: d7fd1f98607f2cd358e583f9548bdf0173090a86 to < add8d7fb04efe564193df73581889c62fc0016f1; 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.