CVE-2024-43887 (GCVE-0-2024-43887)
Vulnerability from cvelistv5
Published
2024-08-26 10:10
Modified
2025-05-04 09:28
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net/tcp: Disable TCP-AO static key after RCU grace period The lifetime of TCP-AO static_key is the same as the last tcp_ao_info. On the socket destruction tcp_ao_info ceases to be with RCU grace period, while tcp-ao static branch is currently deferred destructed. The static key definition is : DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ); which means that if RCU grace period is delayed by more than a second and tcp_ao_needed is in the process of disablement, other CPUs may yet see tcp_ao_info which atent dead, but soon-to-be. And that breaks the assumption of static_key_fast_inc_not_disabled(). See the comment near the definition: > * The caller must make sure that the static key can't get disabled while > * in this function. It doesn't patch jump labels, only adds a user to > * an already enabled static key. Originally it was introduced in commit eb8c507296f6 ("jump_label: Prevent key->enabled int overflow"), which is needed for the atomic contexts, one of which would be the creation of a full socket from a request socket. In that atomic context, it's known by the presence of the key (md5/ao) that the static branch is already enabled. So, the ref counter for that static branch is just incremented instead of holding the proper mutex. static_key_fast_inc_not_disabled() is just a helper for such usage case. But it must not be used if the static branch could get disabled in parallel as it's not protected by jump_label_mutex and as a result, races with jump_label_update() implementation details. Happened on netdev test-bot[1], so not a theoretical issue: [] 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 [] ------------[ cut here ]------------ [] kernel BUG at arch/x86/kernel/jump_label.c:73! [] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI [] CPU: 3 PID: 243 Comm: kworker/3:3 Not tainted 6.10.0-virtme #1 [] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [] Workqueue: events jump_label_update_timeout [] RIP: 0010:__jump_label_patch+0x2f6/0x350 ... [] Call Trace: [] <TASK> [] 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 [] process_one_work+0xe3b/0x1670 [] worker_thread+0x587/0xce0 [] kthread+0x28a/0x350 [] ret_from_fork+0x31/0x70 [] ret_from_fork_asm+0x1a/0x30 [] </TASK> [] Modules linked in: 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
References
Impacted products
Vendor Product Version
Linux Linux Version: 67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43
Version: 67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43
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    "dateReserved": "2024-08-17T09:11:59.288Z",
    "dateUpdated": "2025-05-04T09:28:35.479Z",
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    "nvd": "{\"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\u003e * The caller must make sure that the static key can\u0027t get disabled while\\n\u003e * in this function. It doesn\u0027t patch jump labels, only adds a user to\\n\u003e * an already enabled static key.\\n\\nOriginally it was introduced in commit eb8c507296f6 (\\\"jump_label:\\nPrevent key-\u003eenabled 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\u0027s 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\u0027s 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[]  \u003cTASK\u003e\\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[]  \u003c/TASK\u003e\\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 resolvi\u00f3 la siguiente vulnerabilidad: net/tcp: deshabilite la clave est\u00e1tica TCP-AO despu\u00e9s del per\u00edodo de gracia de RCU. La vida \u00fatil de TCP-AO static_key es la misma que la del \u00faltimo tcp_ao_info. En la destrucci\u00f3n del socket, tcp_ao_info deja de tener un per\u00edodo de gracia de RCU, mientras que la rama est\u00e1tica tcp-ao actualmente se retrasa su destrucci\u00f3n. La definici\u00f3n de clave est\u00e1tica es: DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ); lo que significa que si el per\u00edodo de gracia de la RCU se retrasa m\u00e1s de un segundo y tcp_ao_needed est\u00e1 en proceso de deshabilitaci\u00f3n, es posible que otras CPU a\u00fan vean tcp_ao_info, que est\u00e1 muerto, pero pronto lo estar\u00e1. Y eso rompe la suposici\u00f3n de static_key_fast_inc_not_disabled(). Vea el comentario cerca de la definici\u00f3n: \u0026gt; * El que llama debe asegurarse de que la clave est\u00e1tica no puede conseguir desactivada mientras \u0026gt; * est\u00e1 en esta funci\u00f3n. No parchea etiquetas de salto, s\u00f3lo agrega un usuario a \u0026gt; * una clave est\u00e1tica ya habilitada. Originalmente se introdujo en el commit eb8c507296f6 (\\\"jump_label: Prevent key-\u0026gt;enabled int overflow\\\"), que es necesaria para los contextos at\u00f3micos, uno de los cuales ser\u00eda la creaci\u00f3n de un socket completo a partir de un socket de solicitud. En ese contexto at\u00f3mico, se sabe por la presencia de la clave (md5/ao) que la rama est\u00e1tica ya est\u00e1 habilitada. Entonces, el contador de referencia para esa rama est\u00e1tica 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 est\u00e1tica podr\u00eda deshabilitarse en paralelo ya que no est\u00e1 protegida por jump_label_mutex y, como resultado, corre con los detalles de implementaci\u00f3n de jump_label_update(). Sucedi\u00f3 en netdev test-bot[1], por lo que no es un problema te\u00f3rico: [] jump_label: error fatal del kernel, operaci\u00f3n inesperada en tcp_inbound_hash+0x1a7/0x870 [ffffffffa8c4e9b7] (eb 50 0f 1f 44 != 66 90 0f 1f 00)) tama\u00f1o:2 tipo:1 [] ------------[ cortar aqu\u00ed ]------------ [] ERROR del kernel en arch/x86/kernel/jump_label.c :73! [] Ups: c\u00f3digo de operaci\u00f3n no v\u00e1lido: 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 est\u00e1ndar 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 []  [] M\u00f3dulos 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\"]}]}}",
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      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2024-43887\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-09-10T15:32:02.385131Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-09-11T12:42:12.577Z\"}}], \"cna\": {\"title\": \"net/tcp: Disable TCP-AO static key after RCU grace period\", \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43\", \"lessThan\": \"954d55a59b2501f4a9bd693b40ce45a1c46cb2b3\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43\", \"lessThan\": \"14ab4792ee120c022f276a7e4768f4dcb08f0cdd\", \"versionType\": \"git\"}], \"programFiles\": [\"net/ipv4/tcp_ao.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"6.7\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"6.7\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"6.10.5\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.10.*\"}, {\"status\": \"unaffected\", \"version\": \"6.11\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"net/ipv4/tcp_ao.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/954d55a59b2501f4a9bd693b40ce45a1c46cb2b3\"}, {\"url\": \"https://git.kernel.org/stable/c/14ab4792ee120c022f276a7e4768f4dcb08f0cdd\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"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\u003e * The caller must make sure that the static key can\u0027t get disabled while\\n\u003e * in this function. It doesn\u0027t patch jump labels, only adds a user to\\n\u003e * an already enabled static key.\\n\\nOriginally it was introduced in commit eb8c507296f6 (\\\"jump_label:\\nPrevent key-\u003eenabled 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\u0027s 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\u0027s 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[]  \u003cTASK\u003e\\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[]  \u003c/TASK\u003e\\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\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.10.5\", \"versionStartIncluding\": \"6.7\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.11\", \"versionStartIncluding\": \"6.7\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2025-05-04T09:28:35.479Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2024-43887\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-05-04T09:28:35.479Z\", \"dateReserved\": \"2024-08-17T09:11:59.288Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-08-26T10:10:39.383Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}


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