ksmbd: remove stale channels from all sessions on teardown
In the Linux kernel, the following vulnerability has been resolved: ksmbd: remove stale channels from all sessions on teardown ksmbd_sessions_deregister() removes a connection's channels from other sessions' channel lists only while conn->binding is still set: if (conn->binding) { hash_for_each_safe(sessions_table, ...) ksmbd_chann_del(conn, sess); } conn->binding is a transient flag: it is cleared once a binding SESSION_SETUP completes, and also by a subsequent non-binding SESSION_SETUP on the same connection (a reauthentication on a bound channel, or a new SessionId==0 setup). A connection that has bound a channel into another session's ksmbd_chann_list and then clears conn->binding leaves that channel behind when it disconnects: the channel, whose chann->conn points at the now freed struct ksmbd_conn, stays on the owner session's list. When the owning connection later tears down, the second loop dereferences the stale channel: xa_for_each(&sess->ksmbd_chann_list, chann_id, chann) if (chann->conn != conn) ksmbd_conn_set_exiting(chann->conn); /* freed */ which is a use-after-free write into the freed ksmbd_conn (the same stale channel is also walked by show_proc_session() through /proc). The session is leaked as well, because its channel list never empties. Remove the conn->binding gate so a connection always removes its channels from every session on teardown.
CVE-2026-98870
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98870
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b1b6ed903a6e2b3505a48706bcd499b447ef9e44",
"lessThan": "f8200bb4994e65a2e5c5b314789eeae39078619d",
"versionType": "git"
},
{
"status": "affected",
"version": "47b018dba6ec7ebf403fd2d1e713bc7acc9bbb23",
"lessThan": "9cd6d714d3ca0cff296542dc989696884e41970f",
"versionType": "git"
},
{
"status": "affected",
"version": "9ef4dfd5edbd02f4bf10cd420a30896093d98a67",
"lessThan": "b145f9b56c87f9c23ad5464ab0844dbc1de12b36",
"versionType": "git"
},
{
"status": "affected",
"version": "5a5b0b7a01fe19b383b3c046546b5ae30c1a7d71",
"lessThan": "a15cae16f4432a5ad919ee633e31b07178492955",
"versionType": "git"
},
{
"status": "affected",
"version": "faf8578c77f3d846aca9cd882c293e03eafcc6df",
"lessThan": "b10665730fbf6b5e45fe422badcbbc3f0df96ef5",
"versionType": "git"
},
{
"status": "affected",
"version": "e632f21a8bc0c59abc4960482836ac3782db93c0",
"versionType": "git"
},
{
"status": "affected",
"version": "5.15.222",
"lessThan": "5.16",
"versionType": "semver"
}
],
"programFiles": [
"fs/smb/server/mgmt/user_session.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"programFiles": [
"fs/smb/server/mgmt/user_session.c"
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-98870
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #55699 · Revision 1
- Added to Heist Feed
- Publisher date