mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0
The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement
entry alive when removing the id 0 endpoint. This happens because the id 0
removal path does not tear down pending announcements, unlike the non-zero
id path.
When the PM later reselects id 0 after adding another signal endpoint, it
finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel())
in mptcp_pm_announced_alloc().
Root cause: asymmetry between removal paths.
- Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls
mptcp_pm_remove_announced() to clean up.
- Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.
Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove()
and decrement add_addr_signaled before queuing the RM_ADDR.
Subtle detail: signal endpoints are stored in anno_list with port 0, but
msk_local carries the connection's local port. In other words, entries
linked to ID0 paths should have port == 0. A follow-up patch will ensure
that. mptcp_pm_announced_remove() uses use_port=true for comparison. So
clear the port before the lookup.
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4850-1 | linux-6.12 security update |
Debian DSA |
DSA-6568-1 | linux security update |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Fri, 30 Oct 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 21 Oct 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Sat, 03 Oct 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Thu, 01 Oct 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-391 CWE-682 |
Tue, 29 Sep 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-617 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 25 Sep 2026 23:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-391 CWE-682 |
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not tear down pending announcements, unlike the non-zero id path. When the PM later reselects id 0 after adding another signal endpoint, it finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel()) in mptcp_pm_announced_alloc(). Root cause: asymmetry between removal paths. - Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls mptcp_pm_remove_announced() to clean up. - Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely. Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove() and decrement add_addr_signaled before queuing the RM_ADDR. Subtle detail: signal endpoints are stored in anno_list with port 0, but msk_local carries the connection's local port. In other words, entries linked to ID0 paths should have port == 0. A follow-up patch will ensure that. mptcp_pm_announced_remove() uses use_port=true for comparison. So clear the port before the lookup. | |
| Title | mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-30T12:37:27.459Z
Reserved: 2026-09-24T16:01:01.155Z
Link: CVE-2026-97566
No data.
Status : Received
Published: 2026-09-25T11:17:07.233
Modified: 2026-10-30T13:21:08.483
Link: CVE-2026-97566
OpenCVE Enrichment
Updated: 2026-10-01T11:45:07Z
Debian DLA
Debian DSA