CVE-2024-44991 (GCVE-0-2024-44991)

Vulnerability from cvelistv5 – Published: 2024-09-04 19:54 – Updated: 2026-05-11 20:33
VLAI
Title
tcp: prevent concurrent execution of tcp_sk_exit_batch
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: prevent concurrent execution of tcp_sk_exit_batch Its possible that two threads call tcp_sk_exit_batch() concurrently, once from the cleanup_net workqueue, once from a task that failed to clone a new netns. In the latter case, error unwinding calls the exit handlers in reverse order for the 'failed' netns. tcp_sk_exit_batch() calls tcp_twsk_purge(). Problem is that since commit b099ce2602d8 ("net: Batch inet_twsk_purge"), this function picks up twsk in any dying netns, not just the one passed in via exit_batch list. This means that the error unwind of setup_net() can "steal" and destroy timewait sockets belonging to the exiting netns. This allows the netns exit worker to proceed to call WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount)); without the expected 1 -> 0 transition, which then splats. At same time, error unwind path that is also running inet_twsk_purge() will splat as well: WARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210 ... refcount_dec include/linux/refcount.h:351 [inline] inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70 inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221 inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304 tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 setup_net+0x714/0xb40 net/core/net_namespace.c:375 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 ... because refcount_dec() of tw_refcount unexpectedly dropped to 0. This doesn't seem like an actual bug (no tw sockets got lost and I don't see a use-after-free) but as erroneous trigger of debug check. Add a mutex to force strict ordering: the task that calls tcp_twsk_purge() blocks other task from doing final _dec_and_test before mutex-owner has removed all tw sockets of dying netns.
Severity
No CVSS data available.
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 , < e3d9de3742f4d5c47ae35f888d3023a5b54fcd2f (git)
Affected: e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 , < 99580ae890ec8bd98b21a2a9c6668f8f1555b62e (git)
Affected: e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 , < f6fd2dbf584a4047ba88d1369ff91c9851261ec1 (git)
Affected: e9bd0cca09d13ac2f08d25e195203e42d4ad1ce8 , < 565d121b69980637f040eb4d84289869cdaabedf (git)
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Linux Linux Affected: 6.1
Unaffected: 0 , < 6.1 (semver)
Unaffected: 6.1.107 , ≤ 6.1.* (semver)
Unaffected: 6.6.48 , ≤ 6.6.* (semver)
Unaffected: 6.10.7 , ≤ 6.10.* (semver)
Unaffected: 6.11 , ≤ * (original_commit_for_fix)
Create a notification for this product.
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      "descriptions": "[{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ntcp: prevent concurrent execution of tcp_sk_exit_batch\\n\\nIts possible that two threads call tcp_sk_exit_batch() concurrently,\\nonce from the cleanup_net workqueue, once from a task that failed to clone\\na new netns.  In the latter case, error unwinding calls the exit handlers\\nin reverse order for the \u0027failed\u0027 netns.\\n\\ntcp_sk_exit_batch() calls tcp_twsk_purge().\\nProblem is that since commit b099ce2602d8 (\\\"net: Batch inet_twsk_purge\\\"),\\nthis function picks up twsk in any dying netns, not just the one passed\\nin via exit_batch list.\\n\\nThis means that the error unwind of setup_net() can \\\"steal\\\" and destroy\\ntimewait sockets belonging to the exiting netns.\\n\\nThis allows the netns exit worker to proceed to call\\n\\nWARN_ON_ONCE(!refcount_dec_and_test(\u0026net-\u003eipv4.tcp_death_row.tw_refcount));\\n\\nwithout the expected 1 -\u003e 0 transition, which then splats.\\n\\nAt same time, error unwind path that is also running inet_twsk_purge()\\nwill splat as well:\\n\\nWARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210\\n...\\n refcount_dec include/linux/refcount.h:351 [inline]\\n inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70\\n inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221\\n inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304\\n tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522\\n ops_exit_list+0x128/0x180 net/core/net_namespace.c:178\\n setup_net+0x714/0xb40 net/core/net_namespace.c:375\\n copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508\\n create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110\\n\\n... because refcount_dec() of tw_refcount unexpectedly dropped to 0.\\n\\nThis doesn\u0027t seem like an actual bug (no tw sockets got lost and I don\u0027t\\nsee a use-after-free) but as erroneous trigger of debug check.\\n\\nAdd a mutex to force strict ordering: the task that calls tcp_twsk_purge()\\nblocks other task from doing final _dec_and_test before mutex-owner has\\nremoved all tw sockets of dying netns.\"}, {\"lang\": \"es\", \"value\": \"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tcp: evitar la ejecuci\\u00f3n concurrente de tcp_sk_exit_batch Es posible que dos subprocesos llamen a tcp_sk_exit_batch() simult\\u00e1neamente, una vez desde la cola de trabajo cleanup_net, otra desde una tarea que no pudo clonar una nueva netns. En el \\u00faltimo caso, el desenrollado de errores llama a los controladores de salida en orden inverso para las netns \\\"fallidas\\\". tcp_sk_exit_batch() llama a tcp_twsk_purge(). El problema es que desde el commit b099ce2602d8 (\\\"net: Batch inet_twsk_purge\\\"), esta funci\\u00f3n recoge twsk en cualquier netn moribundo, no solo en el que se pasa a trav\\u00e9s de la lista exit_batch. Esto significa que el desenrollado de errores de setup_net() puede \\\"robar\\\" y destruir los sockets timewait que pertenecen a las netns que salen. Esto permite que el trabajador de salida netns proceda a llamar a WARN_ON_ONCE(!refcount_dec_and_test(\u0026amp;net-\u0026gt;ipv4.tcp_death_row.tw_refcount)); sin la transici\\u00f3n esperada de 1 -\u0026gt; 0, que luego falla. Al mismo tiempo, la ruta de desenrollado de error que tambi\\u00e9n est\\u00e1 ejecutando inet_twsk_purge() tambi\\u00e9n se mostrar\\u00e1: ADVERTENCIA: .. en lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210 ... refcount_dec include/linux/refcount.h:351 [en l\\u00ednea] inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70 inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221 inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304 tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 setup_net+0x714/0xb40 net/core/net_namespace.c:375 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 ... porque refcount_dec() de tw_refcount cay\\u00f3 inesperadamente a 0. Esto no parece un error real (no se perdieron sockets tw y no veo un use-after-free) sino un disparador err\\u00f3neo de la comprobaci\\u00f3n de depuraci\\u00f3n. Agregue un mutex para forzar un orden estricto: la tarea que llama a tcp_twsk_purge() impide que otra tarea realice _dec_and_test final antes de que el propietario del mutex haya eliminado todos los sockets tw de los netn moribundos.\"}]",
      "id": "CVE-2024-44991",
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    "nvd": "{\"cve\":{\"id\":\"CVE-2024-44991\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-09-04T20:15:08.150\",\"lastModified\":\"2025-11-03T23:15:47.283\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ntcp: prevent concurrent execution of tcp_sk_exit_batch\\n\\nIts possible that two threads call tcp_sk_exit_batch() concurrently,\\nonce from the cleanup_net workqueue, once from a task that failed to clone\\na new netns.  In the latter case, error unwinding calls the exit handlers\\nin reverse order for the \u0027failed\u0027 netns.\\n\\ntcp_sk_exit_batch() calls tcp_twsk_purge().\\nProblem is that since commit b099ce2602d8 (\\\"net: Batch inet_twsk_purge\\\"),\\nthis function picks up twsk in any dying netns, not just the one passed\\nin via exit_batch list.\\n\\nThis means that the error unwind of setup_net() can \\\"steal\\\" and destroy\\ntimewait sockets belonging to the exiting netns.\\n\\nThis allows the netns exit worker to proceed to call\\n\\nWARN_ON_ONCE(!refcount_dec_and_test(\u0026net-\u003eipv4.tcp_death_row.tw_refcount));\\n\\nwithout the expected 1 -\u003e 0 transition, which then splats.\\n\\nAt same time, error unwind path that is also running inet_twsk_purge()\\nwill splat as well:\\n\\nWARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210\\n...\\n refcount_dec include/linux/refcount.h:351 [inline]\\n inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70\\n inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221\\n inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304\\n tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522\\n ops_exit_list+0x128/0x180 net/core/net_namespace.c:178\\n setup_net+0x714/0xb40 net/core/net_namespace.c:375\\n copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508\\n create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110\\n\\n... because refcount_dec() of tw_refcount unexpectedly dropped to 0.\\n\\nThis doesn\u0027t seem like an actual bug (no tw sockets got lost and I don\u0027t\\nsee a use-after-free) but as erroneous trigger of debug check.\\n\\nAdd a mutex to force strict ordering: the task that calls tcp_twsk_purge()\\nblocks other task from doing final _dec_and_test before mutex-owner has\\nremoved all tw sockets of dying netns.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tcp: evitar la ejecuci\u00f3n concurrente de tcp_sk_exit_batch Es posible que dos subprocesos llamen a tcp_sk_exit_batch() simult\u00e1neamente, una vez desde la cola de trabajo cleanup_net, otra desde una tarea que no pudo clonar una nueva netns. En el \u00faltimo caso, el desenrollado de errores llama a los controladores de salida en orden inverso para las netns \\\"fallidas\\\". tcp_sk_exit_batch() llama a tcp_twsk_purge(). El problema es que desde el commit b099ce2602d8 (\\\"net: Batch inet_twsk_purge\\\"), esta funci\u00f3n recoge twsk en cualquier netn moribundo, no solo en el que se pasa a trav\u00e9s de la lista exit_batch. Esto significa que el desenrollado de errores de setup_net() puede \\\"robar\\\" y destruir los sockets timewait que pertenecen a las netns que salen. Esto permite que el trabajador de salida netns proceda a llamar a WARN_ON_ONCE(!refcount_dec_and_test(\u0026amp;net-\u0026gt;ipv4.tcp_death_row.tw_refcount)); sin la transici\u00f3n esperada de 1 -\u0026gt; 0, que luego falla. Al mismo tiempo, la ruta de desenrollado de error que tambi\u00e9n est\u00e1 ejecutando inet_twsk_purge() tambi\u00e9n se mostrar\u00e1: ADVERTENCIA: .. en lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210 ... refcount_dec include/linux/refcount.h:351 [en l\u00ednea] inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70 inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221 inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304 tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 setup_net+0x714/0xb40 net/core/net_namespace.c:375 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 ... porque refcount_dec() de tw_refcount cay\u00f3 inesperadamente a 0. Esto no parece un error real (no se perdieron sockets tw y no veo un use-after-free) sino un disparador err\u00f3neo de la comprobaci\u00f3n de depuraci\u00f3n. Agregue un mutex para forzar un orden estricto: la tarea que llama a tcp_twsk_purge() impide que otra tarea realice _dec_and_test final antes de que el propietario del mutex haya eliminado todos los sockets tw de los netn moribundos.\"}],\"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\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.1\",\"versionEndExcluding\":\"6.1.107\",\"matchCriteriaId\":\"8D4DE0F9-B1B3-4577-84CD-11CF847ABCE6\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.6.48\",\"matchCriteriaId\":\"9DE9201A-CE6B-4726-BABB-8265EA0F8AE4\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.7\",\"versionEndExcluding\":\"6.10.7\",\"matchCriteriaId\":\"D2AFDFD1-D95A-4EB7-843B-5E7659518B67\"},{\"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\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"E0005AEF-856E-47EB-BFE4-90C46899394D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"39889A68-6D34-47A6-82FC-CD0BF23D6754\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/565d121b69980637f040eb4d84289869cdaabedf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/99580ae890ec8bd98b21a2a9c6668f8f1555b62e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/e3d9de3742f4d5c47ae35f888d3023a5b54fcd2f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/f6fd2dbf584a4047ba88d1369ff91c9851261ec1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "vulnrichment": {
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In the latter case, error unwinding calls the exit handlers\\nin reverse order for the \u0027failed\u0027 netns.\\n\\ntcp_sk_exit_batch() calls tcp_twsk_purge().\\nProblem is that since commit b099ce2602d8 (\\\"net: Batch inet_twsk_purge\\\"),\\nthis function picks up twsk in any dying netns, not just the one passed\\nin via exit_batch list.\\n\\nThis means that the error unwind of setup_net() can \\\"steal\\\" and destroy\\ntimewait sockets belonging to the exiting netns.\\n\\nThis allows the netns exit worker to proceed to call\\n\\nWARN_ON_ONCE(!refcount_dec_and_test(\u0026net-\u003eipv4.tcp_death_row.tw_refcount));\\n\\nwithout the expected 1 -\u003e 0 transition, which then splats.\\n\\nAt same time, error unwind path that is also running inet_twsk_purge()\\nwill splat as well:\\n\\nWARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210\\n...\\n refcount_dec include/linux/refcount.h:351 [inline]\\n inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70\\n inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221\\n inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304\\n tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522\\n ops_exit_list+0x128/0x180 net/core/net_namespace.c:178\\n setup_net+0x714/0xb40 net/core/net_namespace.c:375\\n copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508\\n create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110\\n\\n... because refcount_dec() of tw_refcount unexpectedly dropped to 0.\\n\\nThis doesn\u0027t seem like an actual bug (no tw sockets got lost and I don\u0027t\\nsee a use-after-free) but as erroneous trigger of debug check.\\n\\nAdd a mutex to force strict ordering: the task that calls tcp_twsk_purge()\\nblocks other task from doing final _dec_and_test before mutex-owner has\\nremoved all tw sockets of dying netns.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.1.107\", \"versionStartIncluding\": \"6.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.6.48\", \"versionStartIncluding\": \"6.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.10.7\", \"versionStartIncluding\": \"6.1\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.11\", \"versionStartIncluding\": \"6.1\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-05-11T20:33:21.068Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2024-44991\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-11T20:33:21.068Z\", \"dateReserved\": \"2024-08-21T05:34:56.671Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-09-04T19:54:38.206Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.