{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-02T00:51:42.468","vulnerabilities":[{"cve":{"id":"CVE-2021-46929","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-02-27T10:15:07.573","lastModified":"2024-11-21T06:34:57.380","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: use call_rcu to free endpoint\n\nThis patch is to delay the endpoint free by calling call_rcu() to fix\nanother use-after-free issue in sctp_sock_dump():\n\n  BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20\n  Call Trace:\n    __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218\n    lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844\n    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]\n    _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168\n    spin_lock_bh include/linux/spinlock.h:334 [inline]\n    __lock_sock+0x203/0x350 net/core/sock.c:2253\n    lock_sock_nested+0xfe/0x120 net/core/sock.c:2774\n    lock_sock include/net/sock.h:1492 [inline]\n    sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324\n    sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091\n    sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527\n    __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049\n    inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065\n    netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244\n    __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352\n    netlink_dump_start include/linux/netlink.h:216 [inline]\n    inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170\n    __sock_diag_cmd net/core/sock_diag.c:232 [inline]\n    sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263\n    netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477\n    sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274\n\nThis issue occurs when asoc is peeled off and the old sk is freed after\ngetting it by asoc->base.sk and before calling lock_sock(sk).\n\nTo prevent the sk free, as a holder of the sk, ep should be alive when\ncalling lock_sock(). This patch uses call_rcu() and moves sock_put and\nep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to\nhold the ep under rcu_read_lock in sctp_transport_traverse_process().\n\nIf sctp_endpoint_hold() returns true, it means this ep is still alive\nand we have held it and can continue to dump it; If it returns false,\nit means this ep is dead and can be freed after rcu_read_unlock, and\nwe should skip it.\n\nIn sctp_sock_dump(), after locking the sk, if this ep is different from\ntsp->asoc->ep, it means during this dumping, this asoc was peeled off\nbefore calling lock_sock(), and the sk should be skipped; If this ep is\nthe same with tsp->asoc->ep, it means no peeloff happens on this asoc,\nand due to lock_sock, no peeloff will happen either until release_sock.\n\nNote that delaying endpoint free won't delay the port release, as the\nport release happens in sctp_endpoint_destroy() before calling call_rcu().\nAlso, freeing endpoint by call_rcu() makes it safe to access the sk by\nasoc->base.sk in sctp_assocs_seq_show() and sctp_rcv().\n\nThanks Jones to bring this issue up.\n\nv1->v2:\n  - improve the changelog.\n  - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed."},{"lang":"es","value":"En el kernel de Linux, se resolvió la siguiente vulnerabilidad: sctp: use call_rcu para liberar el endpoint. Este parche tiene como objetivo retrasar la liberación del endpoint llamando a call_rcu() para solucionar otro problema de use-after-free en sctp_sock_dump(): ERROR: KASAN: use-after-free en __lock_acquire+0x36d9/0x4c20 Rastreo de llamadas: __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_bh include/linux/spinlock_api_smp.h :135 [en línea] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [en línea] __lock_sock+0x203/0x350 net/core/sock.c:2253 lock_sock_nested+0xfe/ 0x120 net/core/sock.c:2774 lock_sock include/net/sock.h:1492 [en línea] sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324 sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c: 5091 sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527 __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065 netlink_dump+0x6 06/0x1080 neto/ netlink/af_netlink.c:2244 __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:216 [en línea] inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170 __sock_diag_cm re neto /core/sock_diag.c:232 [en línea] sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 sock_diag_rcv+0x2a/0x40 net/core/sock_diag. c:274 Este problema ocurre cuando se quita asoc y se libera el sk antiguo después de obtenerlo mediante asoc->base.sk y antes de llamar a lock_sock(sk). Para evitar que sk se libere, como titular de sk, ep debe estar activo al llamar a lock_sock(). Este parche usa call_rcu() y mueve sock_put y ep free a sctp_endpoint_destroy_rcu(), por lo que es seguro intentar mantener el ep bajo rcu_read_lock en sctp_transport_traverse_process(). Si sctp_endpoint_hold() devuelve verdadero, significa que este ep todavía está vivo, lo hemos retenido y podemos continuar descartándolo; Si devuelve falso, significa que este ep está muerto y puede liberarse después de rcu_read_unlock, y debemos omitirlo. En sctp_sock_dump(), después de bloquear el sk, si este ep es diferente de tsp->asoc->ep, significa que durante este volcado, este asoc se eliminó antes de llamar a lock_sock(), y el sk debe omitirse; Si este ep es el mismo con tsp->asoc->ep, significa que no se produce ningún despegue en este asoc y, debido a lock_sock, tampoco se producirá ningún despegue hasta que se libere_sock. Tenga en cuenta que retrasar la liberación del endpoint  no retrasará la liberación del puerto, ya que la liberación del puerto ocurre en sctp_endpoint_destroy() antes de llamar a call_rcu(). Además, liberar el endpoint mediante call_rcu() hace que sea seguro acceder a sk mediante asoc->base.sk en sctp_assocs_seq_show() y sctp_rcv(). Gracias Jones por plantear este problema. v1->v2: - mejorar el registro de cambios. - agregue kfree(ep) a sctp_endpoint_destroy_rcu(), como notó Jakub."}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-416"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.0","versionEndExcluding":"4.14.261","matchCriteriaId":"D04E4F21-CE5F-4E9D-A182-492968E35204"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15.0","versionEndExcluding":"4.19.224","matchCriteriaId":"B34A1353-506A-4AB9-87EC-CD50F09DFB8A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20.0","versionEndExcluding":"5.4.170","matchCriteriaId":"56D16FBB-453E-4316-A027-E517828203D7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5.0","versionEndExcluding":"5.10.90","matchCriteriaId":"C87FB3FD-3E74-4588-A1A4-B9BA8AE0C06B"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11.0","versionEndExcluding":"5.15.13","matchCriteriaId":"083E0940-932B-447B-A6B2-677DAE27FD04"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/5ec7d18d1813a5bead0b495045606c93873aecbb","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/75799e71df1da11394740b43ae5686646179561d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/769d14abd35e0e153b5149c3e1e989a9d719e3ff","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/831de271452b87657fcf8d715ee20519b79caef5","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/8873140f95d4977bf37e4cf0d5c5e3f6e34cdd3e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/af6e6e58f7ebf86b4e7201694b1e4f3a62cbc3ec","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/5ec7d18d1813a5bead0b495045606c93873aecbb","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/75799e71df1da11394740b43ae5686646179561d","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/769d14abd35e0e153b5149c3e1e989a9d719e3ff","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/831de271452b87657fcf8d715ee20519b79caef5","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/8873140f95d4977bf37e4cf0d5c5e3f6e34cdd3e","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/af6e6e58f7ebf86b4e7201694b1e4f3a62cbc3ec","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]}]}}]}