CVE-2024-40949

{"id": "CVE-2024-40949", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2024-07-12T13:15:17.290", "references": [{"url": "https://git.kernel.org/stable/c/8c6c3719ebb7913f8a665d11816d2e38b0eadbab", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9094b4a1c76cfe84b906cc152bab34d4ba26fa5c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8c6c3719ebb7913f8a665d11816d2e38b0eadbab", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/9094b4a1c76cfe84b906cc152bab34d4ba26fa5c", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shmem: fix getting incorrect lruvec when replacing a shmem folio\n\nWhen testing shmem swapin, I encountered the warning below on my machine. \nThe reason is that replacing an old shmem folio with a new one causes\nmem_cgroup_migrate() to clear the old folio's memcg data. As a result,\nthe old folio cannot get the correct memcg's lruvec needed to remove\nitself from the LRU list when it is being freed. This could lead to\npossible serious problems, such as LRU list crashes due to holding the\nwrong LRU lock, and incorrect LRU statistics.\n\nTo fix this issue, we can fallback to use the mem_cgroup_replace_folio()\nto replace the old shmem folio.\n\n[ 5241.100311] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d9960\n[ 5241.100317] head: order:4 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0\n[ 5241.100319] flags: 0x17fffe0000040068(uptodate|lru|head|swapbacked|node=0|zone=2|lastcpupid=0x3ffff)\n[ 5241.100323] raw: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000\n[ 5241.100325] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n[ 5241.100326] head: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000\n[ 5241.100327] head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n[ 5241.100328] head: 17fffe0000000204 fffffdffd6665801 ffffffffffffffff 0000000000000000\n[ 5241.100329] head: 0000000a00000010 0000000000000000 00000000ffffffff 0000000000000000\n[ 5241.100330] page dumped because: VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled())\n[ 5241.100338] ------------[ cut here ]------------\n[ 5241.100339] WARNING: CPU: 19 PID: 78402 at include/linux/memcontrol.h:775 folio_lruvec_lock_irqsave+0x140/0x150\n[...]\n[ 5241.100374] pc : folio_lruvec_lock_irqsave+0x140/0x150\n[ 5241.100375] lr : folio_lruvec_lock_irqsave+0x138/0x150\n[ 5241.100376] sp : ffff80008b38b930\n[...]\n[ 5241.100398] Call trace:\n[ 5241.100399] folio_lruvec_lock_irqsave+0x140/0x150\n[ 5241.100401] __page_cache_release+0x90/0x300\n[ 5241.100404] __folio_put+0x50/0x108\n[ 5241.100406] shmem_replace_folio+0x1b4/0x240\n[ 5241.100409] shmem_swapin_folio+0x314/0x528\n[ 5241.100411] shmem_get_folio_gfp+0x3b4/0x930\n[ 5241.100412] shmem_fault+0x74/0x160\n[ 5241.100414] __do_fault+0x40/0x218\n[ 5241.100417] do_shared_fault+0x34/0x1b0\n[ 5241.100419] do_fault+0x40/0x168\n[ 5241.100420] handle_pte_fault+0x80/0x228\n[ 5241.100422] __handle_mm_fault+0x1c4/0x440\n[ 5241.100424] handle_mm_fault+0x60/0x1f0\n[ 5241.100426] do_page_fault+0x120/0x488\n[ 5241.100429] do_translation_fault+0x4c/0x68\n[ 5241.100431] do_mem_abort+0x48/0xa0\n[ 5241.100434] el0_da+0x38/0xc0\n[ 5241.100436] el0t_64_sync_handler+0x68/0xc0\n[ 5241.100437] el0t_64_sync+0x14c/0x150\n[ 5241.100439] ---[ end trace 0000000000000000 ]---\n\n[baolin.wang@linux.alibaba.com: remove less helpful comments, per Matthew]"}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: mm: shmem: corrige la obtenci\u00f3n de lruvec incorrecto al reemplazar un folio de shmem Al probar shmem swapin, encontr\u00e9 la siguiente advertencia en mi m\u00e1quina. La raz\u00f3n es que reemplazar una publicaci\u00f3n shmem antigua por una nueva hace que mem_cgroup_migrate() borre los datos memcg de la publicaci\u00f3n anterior. Como resultado, el folio antiguo no puede obtener el lruvec de memcg correcto necesario para eliminarse de la lista LRU cuando se libera. Esto podr\u00eda provocar posibles problemas graves, como bloqueos de la lista de LRU debido a que se mantiene el bloqueo de LRU incorrecto y estad\u00edsticas de LRU incorrectas. Para solucionar este problema, podemos utilizar mem_cgroup_replace_folio() para reemplazar el antiguo folio shmem. [ 5241.100311] p\u00e1gina: refcount:0 mapcount:0 mapeo:00000000000000000 index:0x0 pfn:0x5d9960 [ 5241.100317] head: orden:4 mapcount:0 complete_mapcount:0 nr_pages_mapped:0 pincount:0 [ 5241.100319] banderas: 17fffe0000040068(actualizaci\u00f3n|lru |head|swapbacked|node=0|zone=2|lastcpupid=0x3ffff) [ 5241.100323] raw: 17fffe0000040068 ffffdffd6687948 fffffdffd69ae008 0000000000000000 [ 5241.100325] raw: 0000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100326] cabeza: 17fffe0000040068 ffffdffd6687948 ffffdffd69ae008 000000000 [ 5241.100327] cabeza: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100328] cabeza: 17fffe0000000204 fffffdffd6665801 ffffffffffffffff 0000000000000000 [ 5241 .100329] encabezado: 0000000a00000010 0000000000000000 00000000ffffffff 0000000000000000 [5241.100330] p\u00e1gina volcada porque: VM_WARN_ON_ONCE_FOLIO(!memcg &&!mem_cgroup_disable d()) [ 5241.100338] --------- ---[ cortar aqu\u00ed ]------------ [ 5241.100339] ADVERTENCIA: CPU: 19 PID: 78402 en include/linux/memcontrol.h:775 folio_lruvec_lock_irqsave+0x140/0x150 [...] [ 5241.100374] pc : folio_lruvec_lock_irqsave+0x140/0x150 [ 5241.100375] lr : folio_lruvec_lock_irqsave+0x138/0x150 [ 5241.100376] sp : ffff80008b38b930 [...] [ 5241 .100398] Seguimiento de llamadas: [5241.100399] folio_lruvec_lock_irqsave+0x140/0x150 [5241.100401] __page_cache_release+ 0x90/0x300 [ 5241.100404] __folio_put+0x50/0x108 [ 5241.100406] shmem_replace_folio+0x1b4/0x240 [ 5241.100409] shmem_swapin_folio+0x314/0x528 [ 5241.1004 11] shmem_get_folio_gfp+0x3b4/0x930 [ 5241.100412] shmem_fault+0x74/0x160 [ 5241.100414] __do_fault+0x40/ 0x218 [ 5241.100417] do_shared_fault+0x34/0x1b0 [ 5241.100419] do_fault+0x40/0x168 [ 5241.100420] handle_pte_fault+0x80/0x228 [ 5241.100422] 0x1c4/0x440 [ 5241.100424] handle_mm_fault+0x60/0x1f0 [ 5241.100426] do_page_fault+0x120/0x488 [ 5241.100429] do_translation_fault+0x4c/0x68 [ 5241.100431] do_mem_abort+0x48/0xa0 [ 5241.100434] el0_da+0x38/0xc0 [ 5241.100436] [ 5241.100437] el0t_64_sync+0x14c/0x150 [ 5241.100439] ---[ final de seguimiento 00000000000000000 ] --- [baolin.wang@linux.alibaba.com: elimine los comentarios menos \u00fatiles, seg\u00fan Matthew] Enlace: https://lkml.kernel.org/r/ccad3fe1375b468ebca3227b6b729f3eaf9d8046.1718423197.git.baolin.wang@linux.alibaba. com"}], "lastModified": "2025-10-06T20:47:33.097", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0A047AF2-94AC-4A3A-B32D-6AB930D8EF1C", "versionEndExcluding": "6.9.7", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2EBB4392-5FA6-4DA9-9772-8F9C750109FA"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "331C2F14-12C7-45D5-893D-8C52EE38EA10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3173713D-909A-4DD3-9DD4-1E171EB057EE"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.10:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "79F18AFA-40F7-43F0-BA30-7BDB65F918B9"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}