Bug 2568638 (CVE-2026-99277) - CVE-2026-99277 kernel: kernel: ksmbd: Denial of Service via use-after-free in session channel handling
Summary: CVE-2026-99277 kernel: kernel: ksmbd: Denial of Service via use-after-free in...
Keywords:
Status: NEW
Alias: CVE-2026-99277
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-11-07 14:22 UTC by OSIDB Bzimport
Modified: 2026-11-07 20:29 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-11-07 14:22:35 UTC
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Connection cleanup can no longer find the unpublished session to remove its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.


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