{"id":"CVE-2026-97566","published":"2026-09-25T11:17:07.233","lastModified":"2026-09-25T11:17:07.233","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: kernel: drop pending ADD_ADDR when removing ID0\n\nThe in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement\nentry alive when removing the id 0 endpoint. This happens because the id 0\nremoval path does not tear down pending announcements, unlike the non-zero\nid path.\n\nWhen the PM later reselects id 0 after adding another signal endpoint, it\nfinds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel())\nin mptcp_pm_announced_alloc().\n\nRoot cause: asymmetry between removal paths.\n- Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls\n  mptcp_pm_remove_announced() to clean up.\n- Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.\n\nFix by making the id 0 path symmetric: call mptcp_pm_announced_remove()\nand decrement add_addr_signaled before queuing the RM_ADDR.\n\nSubtle detail: signal endpoints are stored in anno_list with port 0, but\nmsk_local carries the connection's local port. In other words, entries\nlinked to ID0 paths should have port == 0. A follow-up patch will ensure\nthat. mptcp_pm_announced_remove() uses use_port=true for comparison. So\nclear the port before the lookup.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/2ac7d6e620764f1fc79eb4edd3610a7a661981ca","tags":[]},{"url":"https://git.kernel.org/stable/c/545616b4e7325be3c61fc082538cb06d14f7b1db","tags":[]},{"url":"https://git.kernel.org/stable/c/d4a67a880654e1bfe318a31bea0bdbb026a09ade","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}