cve-2024-43887
Vulnerability from cvelistv5
Published
2024-08-26 10:10
Modified
2024-12-19 09:17
Severity ?
EPSS score ?
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
{ "containers": { "adp": [ { "metrics": [ { "other": { "content": { "id": "CVE-2024-43887", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "timestamp": "2024-09-10T15:32:02.385131Z", "version": "2.0.3" }, "type": "ssvc" } } ], "providerMetadata": { "dateUpdated": "2024-09-12T17:32:58.944Z", "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP" }, "title": "CISA ADP Vulnrichment" } ], "cna": { "affected": [ { "defaultStatus": "unaffected", "product": "Linux", "programFiles": [ "net/ipv4/tcp_ao.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "lessThan": "954d55a59b2501f4a9bd693b40ce45a1c46cb2b3", "status": "affected", "version": "67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43", "versionType": "git" }, { "lessThan": "14ab4792ee120c022f276a7e4768f4dcb08f0cdd", "status": "affected", "version": "67fa83f7c86a86913ab9cd5a13b4bebd8d2ebb43", "versionType": "git" } ] }, { "defaultStatus": "affected", "product": "Linux", "programFiles": [ "net/ipv4/tcp_ao.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "status": "affected", "version": "6.7" }, { "lessThan": "6.7", "status": "unaffected", "version": "0", "versionType": "semver" }, { "lessThanOrEqual": "6.10.*", "status": "unaffected", "version": "6.10.5", "versionType": "semver" }, { "lessThanOrEqual": "*", "status": "unaffected", "version": "6.11", "versionType": "original_commit_for_fix" } ] } ], "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" } ], "providerMetadata": { "dateUpdated": "2024-12-19T09:17:50.152Z", "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux" }, "references": [ { "url": "https://git.kernel.org/stable/c/954d55a59b2501f4a9bd693b40ce45a1c46cb2b3" }, { "url": "https://git.kernel.org/stable/c/14ab4792ee120c022f276a7e4768f4dcb08f0cdd" } ], "title": "net/tcp: Disable TCP-AO static key after RCU grace period", "x_generator": { "engine": "bippy-5f407fcff5a0" } } }, "cveMetadata": { "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "assignerShortName": "Linux", "cveId": "CVE-2024-43887", "datePublished": "2024-08-26T10:10:39.383Z", "dateReserved": "2024-08-17T09:11:59.288Z", "dateUpdated": "2024-12-19T09:17:50.152Z", "state": "PUBLISHED" }, "dataType": "CVE_RECORD", "dataVersion": "5.1", "meta": { "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\"]}]}}" } }
Loading…
Loading…
Sightings
Author | Source | Type | Date |
---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.