{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-23T11:47:10.643","vulnerabilities":[{"cve":{"id":"CVE-2021-47089","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-03-04T18:15:07.560","lastModified":"2025-04-04T14:41:46.367","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n    unreferenced object 0xffff93d1d8cc02e8 (size 248):\n      comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n      hex dump (first 32 bytes):\n        00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00  .@..............\n        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n      backtrace:\n         seq_open+0x2a/0x80\n         full_proxy_open+0x167/0x1e0\n         do_dentry_open+0x1e1/0x3a0\n         path_openat+0x961/0xa20\n         do_filp_open+0xae/0x120\n         do_sys_openat2+0x216/0x2f0\n         do_sys_open+0x57/0x80\n         do_syscall_64+0x33/0x40\n         entry_SYSCALL_64_after_hwframe+0x44/0xa9\n    unreferenced object 0xffff93d419854000 (size 4096):\n      comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n      hex dump (first 32 bytes):\n        6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30  kfence-#250: 0x0\n        30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d  0000000754bda12-\n      backtrace:\n         seq_read_iter+0x313/0x440\n         seq_read+0x14b/0x1a0\n         full_proxy_read+0x56/0x80\n         vfs_read+0xa5/0x1b0\n         ksys_read+0xa0/0xf0\n         do_syscall_64+0x33/0x40\n         entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan > /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n    do_syscall_64\n      do_sys_open\n        do_dentry_open\n          full_proxy_open\n            seq_open            ---> alloc seq_file\n      vfs_read\n        full_proxy_read\n          seq_read\n            seq_read_iter\n              traverse          ---> alloc seq_buf\n\nAnd it should have been released in the following process:\n\n    do_syscall_64\n      syscall_exit_to_user_mode\n        exit_to_user_mode_prepare\n          task_work_run\n            ____fput\n              __fput\n                full_proxy_release  ---> free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence.  As a result, a memory leak occurs.  Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."},{"lang":"es","value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: kfence: repara la pérdida de memoria cuando los objetos cat kfence Hulk robot informó un problema kmemleak: objeto sin referencia 0xffff93d1d8cc02e8 (tamaño 248): comm \"cat\", pid 23327, jiffies 4624670141 (edad 495992.217s ) volcado hexadecimal (primeros 32 bytes): 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@.............. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................. rastreo inverso: seq_open+0x2a/0x80 full_proxy_open+0x167/0x1e0 do_dentry_open+0x1e1/0x3a0 path_openat+0x961/0xa20 do_filp_open+0xae/0x120 do_sys_openat2+0x216/0x2f0 do_sys_open+0x57/0x80 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 objeto sin referencia 0xffff93d419854000 (tamaño 4096): comm \"cat\", pid 23327, Jiffies 4624670141 (edad 495992,217 s) volcado hexadecimal (primeros 32 bytes) : 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda1 2- rastreo inverso: seq_read_iter+0x313/0x440 seq_read+ 0x14b/0x1a0 full_proxy_read+0x56/0x80 vfs_read+0xa5/0x1b0 ksys_read+0xa0/0xf0 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 Creo que podemos reproducir fácilmente este problema con los siguientes comandos: cat /sys/kernel/ depurar/ kfence/objects echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak La memoria filtrada se asigna en la pila siguiente: do_syscall_64 do_sys_open do_dentry_open full_proxy_open seq_open ---> alloc seq_file vfs_read full_proxy_read seq_read seq_read_iter traverse - --> alloc seq_buf Y debería haberse liberado en el siguiente proceso: do_syscall_64 syscall_exit_to_user_mode exit_to_user_mode_prepare task_work_run ____fput __fput full_proxy_release ---> free aquí Sin embargo, la función de liberación correspondiente a file_operatives no está implementada en kfence. Como resultado, se produce una pérdida de memoria. Por tanto, la solución a este problema es implementar la función de liberación correspondiente."}],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","baseScore":3.3,"baseSeverity":"LOW","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":1.8,"impactScore":1.4}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-401"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"5.15.12","matchCriteriaId":"5CAD6D48-E560-4E57-93BC-36BEBD6A8FA6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*","matchCriteriaId":"357AA433-37E8-4323-BFB2-3038D6E4B414"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*","matchCriteriaId":"A73429BA-C2D9-4D0C-A75F-06A1CA8B3983"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*","matchCriteriaId":"F621B5E3-E99D-49E7-90B9-EC3B77C95383"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*","matchCriteriaId":"F7BFDCAA-1650-49AA-8462-407DD593F94F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*","matchCriteriaId":"6EC9882F-866D-4ACB-8FBC-213D8D8436C8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*","matchCriteriaId":"8A0915FE-A4AA-4C94-B783-CF29D81E7E54"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]}]}}]}