CVE-2026-64045

{"id": "CVE-2026-64045", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.4, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.5}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "11851cbd60ea1e5abbd97619d69845ead99303d6", "lessThan": "e5460eb7238c19d651a9b22b2378b587033a4095", "versionType": "git"}, {"status": "affected", "version": "11851cbd60ea1e5abbd97619d69845ead99303d6", "lessThan": "d3ef441907fca7c340979e577a3db3bb634bf166", "versionType": "git"}, {"status": "affected", "version": "11851cbd60ea1e5abbd97619d69845ead99303d6", "lessThan": "775d8d7ad02aa345e1588424a6a8b9ae49fb9012", "versionType": "git"}], "programFiles": ["drivers/net/ovpn/tcp.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.16"}, {"status": "unaffected", "version": "0", "lessThan": "6.16", "versionType": "semver"}, {"status": "unaffected", "version": "6.18.34", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.11", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/net/ovpn/tcp.c"], "defaultStatus": "affected"}]}], "published": "2026-07-19T16:17:44.803", "references": [{"url": "https://git.kernel.org/stable/c/775d8d7ad02aa345e1588424a6a8b9ae49fb9012", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d3ef441907fca7c340979e577a3db3bb634bf166", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e5460eb7238c19d651a9b22b2378b587033a4095", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: tcp - use cached peer pointer in ovpn_tcp_close()\n\novpn_tcp_close() loads the ovpn_socket via rcu_dereference_sk_user_data()\nunder rcu_read_lock(), takes a reference on sock->peer, caches the peer\npointer in a local, and drops the read lock. It then passes sock->peer\n(rather than the cached local) to ovpn_peer_del(), re-dereferencing the\novpn_socket after the RCU read section has ended.\n\nUnlike ovpn_tcp_sendmsg(), which uses the same \"load under RCU, use\nafter unlock\" pattern but is protected by lock_sock() held across the\nfunction, ovpn_tcp_close() runs without the socket lock: inet_release()\ninvokes sk_prot->close() without taking lock_sock first.\n\novpn_socket_release() can therefore complete its kref_put -> detach ->\nsynchronize_rcu -> kfree(sock) sequence concurrently, in the window\nafter ovpn_tcp_close() drops rcu_read_lock() but before it dereferences\nsock->peer. The synchronize_rcu() in ovpn_socket_release() protects\nreaders that use the dereferenced pointer inside the RCU read section,\nnot those that escape the pointer to a local and use it afterwards.\n\nA reproducer follows the pattern of commit 94560267d6c4 (\"ovpn: tcp -\ndon't deref NULL sk_socket member after tcp_close()\"): trigger a peer\nremoval (keepalive expiration or netlink OVPN_CMD_DEL_PEER) at the same\nmoment userspace closes the TCP fd. That commit fixed the detach-side\nof the same race window; this one fixes the close-side at a different\nvictim.\n\nTighten the entry block to read sock->peer exactly once into the cached\npeer local, and route all subsequent uses (the hold check, the\novpn_peer_del() call, and the prot->close() invocation) through that\nlocal. sock->peer is only ever written once in ovpn_socket_new() under\nlock_sock(), before rcu_assign_sk_user_data() publishes the ovpn_socket,\nand is never reassigned afterwards - but the previous multi-read pattern\nmade that invariant implicit rather than explicit. The same multi-read\nshape exists in ovpn_tcp_recvmsg(), ovpn_tcp_sendmsg(),\novpn_tcp_data_ready() and ovpn_tcp_write_space(); those will be cleaned\nup via a dedicated helper in a follow-up net-next series."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\novpn: tcp - usar puntero de par en cach\u00e9 en ovpn_tcp_close()\n\novpn_tcp_close() carga el ovpn_socket a trav\u00e9s de rcu_dereference_sk_user_data() bajo rcu_read_lock(), toma una referencia en sock -> peer, almacena en cach\u00e9 el puntero del par en una variable local, y libera el bloqueo de lectura. Luego pasa sock -> peer (en lugar de la variable local en cach\u00e9) a ovpn_peer_del(), volviendo a desreferenciar el ovpn_socket despu\u00e9s de que la secci\u00f3n de lectura RCU haya terminado.\n\nA diferencia de ovpn_tcp_sendmsg(), que utiliza el mismo patr\u00f3n de \u2019cargar bajo RCU, usar despu\u00e9s de desbloquear\u2019 pero est\u00e1 protegido por lock_sock() mantenido durante toda la funci\u00f3n, ovpn_tcp_close() se ejecuta sin el bloqueo del socket: inet_release() invoca sk_prot -> close() sin tomar lock_sock primero.\n\nPor lo tanto, ovpn_socket_release() puede completar su secuencia kref_put -> detach -> synchronize_rcu -> kfree(sock) concurrentemente, en la ventana despu\u00e9s de que ovpn_tcp_close() libera rcu_read_lock() pero antes de que desreferencie sock -> peer. El synchronize_rcu() en ovpn_socket_release() protege a los lectores que usan el puntero desreferenciado dentro de la secci\u00f3n de lectura RCU, no a aquellos que escapan el puntero a una variable local y lo usan despu\u00e9s.\n\nUn reproductor sigue el patr\u00f3n del commit 94560267d6c4 (\u2019ovpn: tcp - no desreferenciar miembro sk_socket NULL despu\u00e9s de tcp_close()\u2019): activar una eliminaci\u00f3n de par (expiraci\u00f3n de keepalive o netlink OVPN_CMD_DEL_PEER) en el mismo momento en que el espacio de usuario cierra el descriptor de archivo TCP. Ese commit corrigi\u00f3 el lado de desvinculaci\u00f3n de la misma ventana de carrera; este corrige el lado de cierre en una v\u00edctima diferente.\n\nAjustar el bloque de entrada para leer sock -> peer exactamente una vez en la variable local del par en cach\u00e9, y enrutar todos los usos subsiguientes (la verificaci\u00f3n de retenci\u00f3n, la llamada a ovpn_peer_del() y la invocaci\u00f3n de prot -> close()) a trav\u00e9s de esa variable local. sock -> peer solo se escribe una vez en ovpn_socket_new() bajo lock_sock(), antes de que rcu_assign_sk_user_data() publique el ovpn_socket, y nunca se reasigna despu\u00e9s, pero el patr\u00f3n de m\u00faltiples lecturas anterior hizo que ese invariante fuera impl\u00edcito en lugar de expl\u00edcito. La misma forma de m\u00faltiples lecturas existe en ovpn_tcp_recvmsg(), ovpn_tcp_sendmsg(), ovpn_tcp_data_ready() y ovpn_tcp_write_space(); estos se limpiar\u00e1n mediante una funci\u00f3n auxiliar dedicada en una serie net-next de seguimiento."}], "lastModified": "2026-10-24T20:10:00.137", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2437F48D-051C-4E78-83C2-F198D0F2AE92", "versionEndExcluding": "6.18.34", "versionStartIncluding": "6.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750", "versionEndExcluding": "7.0.11", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}