CVE-2024-45000

{"id": "CVE-2024-45000", "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": "2024-09-04T20:15:08.657", "references": [{"url": "https://git.kernel.org/stable/c/0a4d41fa14b2a0efd40e350cfe8ec6a4c998ac1d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b8a50877f68efdcc0be3fcc5116e00c31b90e45b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dfaa39b05a6cf34a16c525a2759ee6ab26b5fef6", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f71aa06398aabc2e3eaac25acdf3d62e0094ba70", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/netfs/fscache_cookie: add missing \"n_accesses\" check\n\nThis fixes a NULL pointer dereference bug due to a data race which\nlooks like this:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000008\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: 0000 [#1] SMP PTI\n CPU: 33 PID: 16573 Comm: kworker/u97:799 Not tainted 6.8.7-cm4all1-hp+ #43\n Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018\n Workqueue: events_unbound netfs_rreq_write_to_cache_work\n RIP: 0010:cachefiles_prepare_write+0x30/0xa0\n Code: 57 41 56 45 89 ce 41 55 49 89 cd 41 54 49 89 d4 55 53 48 89 fb 48 83 ec 08 48 8b 47 08 48 83 7f 10 00 48 89 34 24 48 8b 68 20 <48> 8b 45 08 4c 8b 38 74 45 49 8b 7f 50 e8 4e a9 b0 ff 48 8b 73 10\n RSP: 0018:ffffb4e78113bde0 EFLAGS: 00010286\n RAX: ffff976126be6d10 RBX: ffff97615cdb8438 RCX: 0000000000020000\n RDX: ffff97605e6c4c68 RSI: ffff97605e6c4c60 RDI: ffff97615cdb8438\n RBP: 0000000000000000 R08: 0000000000278333 R09: 0000000000000001\n R10: ffff97605e6c4600 R11: 0000000000000001 R12: ffff97605e6c4c68\n R13: 0000000000020000 R14: 0000000000000001 R15: ffff976064fe2c00\n FS: 0000000000000000(0000) GS:ffff9776dfd40000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000000000000008 CR3: 000000005942c002 CR4: 00000000001706f0\n Call Trace:\n <TASK>\n ? __die+0x1f/0x70\n ? page_fault_oops+0x15d/0x440\n ? search_module_extables+0xe/0x40\n ? fixup_exception+0x22/0x2f0\n ? exc_page_fault+0x5f/0x100\n ? asm_exc_page_fault+0x22/0x30\n ? cachefiles_prepare_write+0x30/0xa0\n netfs_rreq_write_to_cache_work+0x135/0x2e0\n process_one_work+0x137/0x2c0\n worker_thread+0x2e9/0x400\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xcc/0x100\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x30/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1b/0x30\n </TASK>\n Modules linked in:\n CR2: 0000000000000008\n ---[ end trace 0000000000000000 ]---\n\nThis happened because fscache_cookie_state_machine() was slow and was\nstill running while another process invoked fscache_unuse_cookie();\nthis led to a fscache_cookie_lru_do_one() call, setting the\nFSCACHE_COOKIE_DO_LRU_DISCARD flag, which was picked up by\nfscache_cookie_state_machine(), withdrawing the cookie via\ncachefiles_withdraw_cookie(), clearing cookie->cache_priv.\n\nAt the same time, yet another process invoked\ncachefiles_prepare_write(), which found a NULL pointer in this code\nline:\n\n struct cachefiles_object *object = cachefiles_cres_object(cres);\n\nThe next line crashes, obviously:\n\n struct cachefiles_cache *cache = object->volume->cache;\n\nDuring cachefiles_prepare_write(), the \"n_accesses\" counter is\nnon-zero (via fscache_begin_operation()). The cookie must not be\nwithdrawn until it drops to zero.\n\nThe counter is checked by fscache_cookie_state_machine() before\nswitching to FSCACHE_COOKIE_STATE_RELINQUISHING and\nFSCACHE_COOKIE_STATE_WITHDRAWING (in \"case\nFSCACHE_COOKIE_STATE_FAILED\"), but not for\nFSCACHE_COOKIE_STATE_LRU_DISCARDING (\"case\nFSCACHE_COOKIE_STATE_ACTIVE\").\n\nThis patch adds the missing check. With a non-zero access counter,\nthe function returns and the next fscache_end_cookie_access() call\nwill queue another fscache_cookie_state_machine() call to handle the\nstill-pending FSCACHE_COOKIE_DO_LRU_DISCARD."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fs/netfs/fscache_cookie: agregar comprobaci\u00f3n \"n_accesses\" faltante Esto corrige un error de desreferencia de puntero NULL debido a una ejecuci\u00f3n de datos que se ve as\u00ed: ERROR: desreferencia de puntero NULL del kernel, direcci\u00f3n: 0000000000000008 #PF: acceso de lectura de supervisor en modo kernel #PF: error_code(0x0000) - p\u00e1gina no presente PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 33 PID: 16573 Comm: kworker/u97:799 No contaminado 6.8.7-cm4all1-hp+ #43 Nombre del hardware: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 17/10/2018 Cola de trabajo: events_unbound netfs_rreq_write_to_cache_work RIP: 0010:cachefiles_prepare_write+0x30/0xa0 C\u00f3digo: 57 41 56 45 89 ce 41 55 49 89 cd 41 54 49 89 d4 55 53 48 89 fb 48 83 ec 08 48 8b 47 08 48 83 7f 10 00 48 89 34 24 48 8b 68 20 &lt;48&gt; 8b 45 08 4c 8b 38 74 45 49 8b 7f 50 e8 4e a9 b0 ff 48 8b 73 10 RSP: 0018:ffffb4e78113bde0 EFLAGS: 00010286 RAX: ffff976126be6d10 RBX: ffff97615cdb8438 RCX: 0000000000020000 RDX: ffff97605e6c4c68 RSI: ffff97605e6c4c60 RDI: ffff97615cdb8438 RBP: 000000000000000 R08: 0000000000278333 R09: 0000000000000001 R10: ffff97605e6c4600 R11: 0000000000000001 R12: ffff97605e6c4c68 R13: 0000000000020000 R14: 0000000000000001 R15: ffff976064fe2c00 FS: 000000000000000(0000) GS:ffff9776dfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000008 CR3: 000000005942c002 CR4: 00000000001706f0 Seguimiento de llamadas: ? __die+0x1f/0x70 ? page_fault_oops+0x15d/0x440 ? search_module_extables+0xe/0x40 ? fixup_exception+0x22/0x2f0 ? exc_page_fault+0x5f/0x100 ? asm_exc_page_fault+0x22/0x30 ? cachefiles_prepare_write+0x30/0xa0 netfs_rreq_write_to_cache_work+0x135/0x2e0 process_one_work+0x137/0x2c0 subproceso_trabajador+0x2e9/0x400 ? __pfx_worker_thread+0x10/0x10 kthread+0xcc/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 M\u00f3dulos vinculados en: CR2: 000000000000008 ---[ fin del seguimiento 000000000000000 ]--- Esto sucedi\u00f3 porque fscache_cookie_state_machine() era lento y todav\u00eda se estaba ejecutando mientras otro proceso invocaba fscache_unuse_cookie(); Esto llev\u00f3 a una llamada a fscache_cookie_lru_do_one(), que estableci\u00f3 el indicador FSCACHE_COOKIE_DO_LRU_DISCARD, que fue detectado por fscache_cookie_state_machine(), retirando la cookie a trav\u00e9s de cachefiles_withdraw_cookie(), borrando cookie-&gt;cache_priv. Al mismo tiempo, otro proceso invoc\u00f3 cachefiles_prepare_write(), que encontr\u00f3 un puntero NULL en esta l\u00ednea de c\u00f3digo: struct cachefiles_object *object = cachefiles_cres_object(cres); La siguiente l\u00ednea falla, obviamente: struct cachefiles_cache *cache = object-&gt;volume-&gt;cache; Durante cachefiles_prepare_write(), el contador \"n_accesses\" no es cero (a trav\u00e9s de fscache_begin_operation()). La cookie no debe retirarse hasta que baje a cero. El contador se comprueba mediante fscache_cookie_state_machine() antes de cambiar a FSCACHE_COOKIE_STATE_RELINQUISHING y FSCACHE_COOKIE_STATE_WITHDRAWING (en el \"caso FSCACHE_COOKIE_STATE_FAILED\"), pero no para FSCACHE_COOKIE_STATE_LRU_DISCARDING (\"caso FSCACHE_COOKIE_STATE_ACTIVE\"). Este parche agrega la comprobaci\u00f3n faltante. Con un contador de acceso distinto de cero, la funci\u00f3n retorna y la siguiente llamada fscache_end_cookie_access() pondr\u00e1 en cola otra llamada fscache_cookie_state_machine() para manejar la FSCACHE_COOKIE_DO_LRU_DISCARD a\u00fan pendiente."}], "lastModified": "2024-09-06T16:27:31.003", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E1FCBB3B-3EA3-4D99-B4C1-E8EA9F3DA097", "versionEndExcluding": "6.1.107", "versionStartIncluding": "5.17"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9DE9201A-CE6B-4726-BABB-8265EA0F8AE4", "versionEndExcluding": "6.6.48", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D2AFDFD1-D95A-4EB7-843B-5E7659518B67", "versionEndExcluding": "6.10.7", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8B3CE743-2126-47A3-8B7C-822B502CF119"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4DEB27E7-30AA-45CC-8934-B89263EF3551"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E0005AEF-856E-47EB-BFE4-90C46899394D"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}