{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-05T23:57:45.429","vulnerabilities":[{"cve":{"id":"CVE-2024-43887","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-08-26T11:15:03.877","lastModified":"2024-09-05T19:43:44.197","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp: Disable TCP-AO static key after RCU grace period\n\nThe lifetime of TCP-AO static_key is the same as the last\ntcp_ao_info. On the socket destruction tcp_ao_info ceases to be\nwith RCU grace period, while tcp-ao static branch is currently deferred\ndestructed. The static key definition is\n: DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);\n\nwhich means that if RCU grace period is delayed by more than a second\nand tcp_ao_needed is in the process of disablement, other CPUs may\nyet see tcp_ao_info which atent dead, but soon-to-be.\nAnd that breaks the assumption of static_key_fast_inc_not_disabled().\n\nSee the comment near the definition:\n> * The caller must make sure that the static key can't get disabled while\n> * in this function. It doesn't patch jump labels, only adds a user to\n> * an already enabled static key.\n\nOriginally it was introduced in commit eb8c507296f6 (\"jump_label:\nPrevent key->enabled int overflow\"), which is needed for the atomic\ncontexts, one of which would be the creation of a full socket from a\nrequest socket. In that atomic context, it's known by the presence\nof the key (md5/ao) that the static branch is already enabled.\nSo, the ref counter for that static branch is just incremented\ninstead of holding the proper mutex.\nstatic_key_fast_inc_not_disabled() is just a helper for such usage\ncase. But it must not be used if the static branch could get disabled\nin parallel as it's not protected by jump_label_mutex and as a result,\nraces with jump_label_update() implementation details.\n\nHappened on netdev test-bot[1], so not a theoretical issue:\n\n[] jump_label: Fatal kernel bug, unexpected op at tcp_inbound_hash+0x1a7/0x870 [ffffffffa8c4e9b7] (eb 50 0f 1f 44 != 66 90 0f 1f 00)) size:2 type:1\n[] ------------[ cut here ]------------\n[] kernel BUG at arch/x86/kernel/jump_label.c:73!\n[] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI\n[] CPU: 3 PID: 243 Comm: kworker/3:3 Not tainted 6.10.0-virtme #1\n[] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\n[] Workqueue: events jump_label_update_timeout\n[] RIP: 0010:__jump_label_patch+0x2f6/0x350\n...\n[] Call Trace:\n[]  <TASK>\n[]  arch_jump_label_transform_queue+0x6c/0x110\n[]  __jump_label_update+0xef/0x350\n[]  __static_key_slow_dec_cpuslocked.part.0+0x3c/0x60\n[]  jump_label_update_timeout+0x2c/0x40\n[]  process_one_work+0xe3b/0x1670\n[]  worker_thread+0x587/0xce0\n[]  kthread+0x28a/0x350\n[]  ret_from_fork+0x31/0x70\n[]  ret_from_fork_asm+0x1a/0x30\n[]  </TASK>\n[] Modules linked in: veth\n[] ---[ end trace 0000000000000000 ]---\n[] RIP: 0010:__jump_label_patch+0x2f6/0x350\n\n[1]: https://netdev-3.bots.linux.dev/vmksft-tcp-ao-dbg/results/696681/5-connect-deny-ipv6/stderr"},{"lang":"es","value":"En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net/tcp: deshabilite la clave estática TCP-AO después del período de gracia de RCU. La vida útil de TCP-AO static_key es la misma que la del último tcp_ao_info. En la destrucción del socket, tcp_ao_info deja de tener un período de gracia de RCU, mientras que la rama estática tcp-ao actualmente se retrasa su destrucción. La definición de clave estática es: DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ); lo que significa que si el período de gracia de la RCU se retrasa más de un segundo y tcp_ao_needed está en proceso de deshabilitación, es posible que otras CPU aún vean tcp_ao_info, que está muerto, pero pronto lo estará. Y eso rompe la suposición de static_key_fast_inc_not_disabled(). Vea el comentario cerca de la definición: &gt; * El que llama debe asegurarse de que la clave estática no puede conseguir desactivada mientras &gt; * está en esta función. No parchea etiquetas de salto, sólo agrega un usuario a &gt; * una clave estática ya habilitada. Originalmente se introdujo en el commit eb8c507296f6 (\"jump_label: Prevent key-&gt;enabled int overflow\"), que es necesaria para los contextos atómicos, uno de los cuales sería la creación de un socket completo a partir de un socket de solicitud. En ese contexto atómico, se sabe por la presencia de la clave (md5/ao) que la rama estática ya está habilitada. Entonces, el contador de referencia para esa rama estática simplemente se incrementa en lugar de mantener el mutex adecuado. static_key_fast_inc_not_disabled() es solo una ayuda para tal caso de uso. Pero no debe usarse si la rama estática podría deshabilitarse en paralelo ya que no está protegida por jump_label_mutex y, como resultado, corre con los detalles de implementación de jump_label_update(). Sucedió en netdev test-bot[1], por lo que no es un problema teórico: [] jump_label: error fatal del kernel, operación inesperada en tcp_inbound_hash+0x1a7/0x870 [ffffffffa8c4e9b7] (eb 50 0f 1f 44 != 66 90 0f 1f 00)) tamaño:2 tipo:1 [] ------------[ cortar aquí ]------------ [] ERROR del kernel en arch/x86/kernel/jump_label.c :73! [] Ups: código de operación no válido: 0000 [#1] PREEMPT SMP KASAN NOPTI [] CPU: 3 PID: 243 Comm: kworker/3:3 Not tainted 6.10.0-virtme #1 [] Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 01/04/2014 [] Cola de trabajo: eventos jump_label_update_timeout [] RIP: 0010:__jump_label_patch+0x2f6/0x350... [] Llamada Seguimiento: []  [] arch_jump_label_transform_queue+0x6c/0x110 [] __jump_label_update+0xef/0x350 [] __static_key_slow_dec_cpuslocked.part.0+0x3c/0x60 [] jump_label_update_timeout+0x2c/0x40 [] 0x1670 [] hilo_trabajador+ 0x587/0xce0 [] kthread+0x28a/0x350 [] ret_from_fork+0x31/0x70 [] ret_from_fork_asm+0x1a/0x30 []  [] Módulos vinculados en: veth [] ---[ end trace 0000000000000000 ]--- [] RIP: 0010:__jump_label_patch+0x2f6/0x350 [1]: https://netdev-3.bots.linux.dev/vmksft-tcp-ao-dbg/results/696681/5-connect-deny-ipv6/stderr"}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":4.7,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.0,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"NVD-CWE-noinfo"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.10.5","matchCriteriaId":"D074AE50-4A5E-499C-A2FD-75FD60DEA560"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*","matchCriteriaId":"8B3CE743-2126-47A3-8B7C-822B502CF119"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*","matchCriteriaId":"4DEB27E7-30AA-45CC-8934-B89263EF3551"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/14ab4792ee120c022f276a7e4768f4dcb08f0cdd","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/954d55a59b2501f4a9bd693b40ce45a1c46cb2b3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]}]}}]}