CVE-2026-80784mptcp: pm: fix memory leak from alloc-during-teardown race
- —Not scoredno CVSS score yet
- 0.17%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: fix memory leak from alloc-during-teardown race mptcp_pm_destroy() empties msk->pm.anno_list and msk->pm.userspace_pm_local_addr_list under msk->pm.lock during socket teardown, dropping the lock between the two. A concurrent userspace PM genl ANNOUNCE on the same msk holds a sock reference via mptcp_token_get_sock() and, in mptcp_pm_nl_announce_doit(), calls mptcp_userspace_pm_append_new_local_addr() and mptcp_pm_announced_alloc(). Both take msk->pm.lock briefly to add to their respective lists. Because the genl handler holds a sock reference, mptcp_pm_destroy() may run on the same msk via mptcp_disconnect(), which invokes mptcp_destroy_common() without dropping the sock refcount, before the handler completes. If the lock acquisitions interleave such that mptcp_pm_destroy() empties a list first, the later alloc adds its entry to a list head that nothing else iterates for this msk, and the entry leaks. kmemleak reports both mptcp_pm_add_addr objects (from mptcp_pm_announced_alloc()) and mptcp_pm_addr_entry objects (from mptcp_userspace_pm_append_new_local_addr()) under sustained concurrent ANNOUNCE + close load against the userspace PM. Add an MPTCP_PM_DESTROYING bit in msk->pm.status, set by mptcp_pm_destroy() under pm.lock before the lists are emptied and checked under pm.lock by the alloc paths. Either the alloc takes pm.lock first, in which case its entry is on the list when mptcp_pm_destroy() frees it; or mptcp_pm_destroy() takes pm.lock first, in which case the later alloc observes the bit and refuses. Found by an MPTCP protocol-flow harness extending BRF (arXiv:2305.08782).
Timeline
ID reserved
By Linux
- 9 days later
· 9 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.17% · top 93% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < f48341830e4202db3fe884b819b2db6740f0537d
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < bb32e9a6a9a9f99eeda16c4efe443400f3e43892
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < 9fe5eebb664ecdba88f3fde18062d94b1d1c465f
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < 6c290915a03fc8228b473641025cf762b256dbd2
- affected 9ab4807c84a4aacfc9b4f79cc81254035e0ec361 – < efc33b5102ff859bacd390a5f30112d8e0c084c0
- affected 5.19
- unaffected < 5.19
- unaffected 6.1.187 – ≤ 6.1.*
- unaffected 6.6.154 – ≤ 6.6.*
- unaffected 6.12.106 – ≤ 6.12.*
- unaffected 6.18.47 – ≤ 6.18.*
- unaffected 7.1.11 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References6
- https://git.kernel.org/stable/c/f48341830e4202db3fe884b819b2db6740f0537d (opens in a new tab)
- https://git.kernel.org/stable/c/bb32e9a6a9a9f99eeda16c4efe443400f3e43892 (opens in a new tab)
- https://git.kernel.org/stable/c/b2a0b55bf613bd3e81ed26a847b0f6b8e6b7f804 (opens in a new tab)
- https://git.kernel.org/stable/c/9fe5eebb664ecdba88f3fde18062d94b1d1c465f (opens in a new tab)
- https://git.kernel.org/stable/c/6c290915a03fc8228b473641025cf762b256dbd2 (opens in a new tab)
- https://git.kernel.org/stable/c/efc33b5102ff859bacd390a5f30112d8e0c084c0 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-71427 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-80784)Record last updated .